1
|
Higgs MG, Greenwald MA, Roca C, Macdonald JK, Sidders AE, Conlon BP, Wolfgang MC. Flagellar motility and the mucus environment influence aggregation-mediated antibiotic tolerance of Pseudomonas aeruginosa in chronic lung infection. mBio 2025:e0083125. [PMID: 40372059 DOI: 10.1128/mbio.00831-25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2025] [Accepted: 04/15/2025] [Indexed: 05/16/2025] Open
Abstract
Pseudomonas aeruginosa routinely causes chronic lung infection in individuals with muco-obstructive airway diseases (MADs). In MADs, P. aeruginosa forms antibiotic-tolerant biofilm-like aggregates within hyperconcentrated airway mucus. While the contribution of mucin hyper-concentration to antibiotic tolerance and bacterial aggregation has been described, less is known about the bacterial factors involved. We previously found that P. aeruginosa populations isolated from people with MADs exhibited significant variability in antibiotic tolerance. This variability is not explained by antibiotic resistance or the mucus environment, suggesting bacterial-driven mechanisms play a crucial role in treatment outcomes. Here, we investigated the contribution of flagellar motility to aggregate formation and tolerance by manipulating motility behaviors. Similar to prior studies, we found that loss of flagellar motility resulted in increased aggregation and tolerance to various antibiotics. We identified novel differential roles of the MotAB and MotCD stators, which power flagellar rotation, in antimicrobial tolerance and aggregate formation. In addition, we found that control of fliC expression was important for aggregate formation and antibiotic tolerance. Constitutive expression of fliC allowed P. aeruginosa to overcome entropic forces of mucin, antagonizing aggregate formation and increasing antibiotic efficacy. Lastly, we demonstrate that neutrophil elastase, an abundant antimicrobial protease in chronic lung infection, promotes antibiotic treatment failure by impairing flagellar motility leading to antibiotic-tolerant aggregate formation. These results underscore the crucial role of flagellar motility in aggregate formation and antibiotic tolerance, enhancing our understanding of how P. aeruginosa adapts to the MADs lung environment. IMPORTANCE Antibiotic treatment failure of Pseudomonas aeruginosa infection is a key driver of mortality in muco-obstructive airway diseases (MADs). The bacterial mechanisms that contribute to antibiotic tolerance in MADS infection are poorly understood. We investigated the impact of swimming motility behaviors on P. aeruginosa antibiotic tolerance in the context of the diseased mucus environment. Loss of flagellar motility, a common adaptation in chronic lung infection, drives antibiotic tolerance by promoting aggregate formation under physiologically relevant mucin concentrations. We uncovered novel roles of the flagellar stators in motility and mucus aggregate formation. Furthermore, neutrophil elastase, an abundant host-derived antimicrobial protease, promotes antibiotic tolerance and aggregation by impairing flagellar motility. These results further our understanding of the formation of antibiotic-tolerant aggregates within the MADs airway, revealing potential new targets to improve antibiotic treatment of chronic P. aeruginosa airway infection.
Collapse
Affiliation(s)
- Matthew G Higgs
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Matthew A Greenwald
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Cristian Roca
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jade K Macdonald
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ashelyn E Sidders
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Brian P Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Matthew C Wolfgang
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| |
Collapse
|
2
|
Van Loon JC, Le Mauff F, Vargas MA, Gilbert S, Pfoh R, Morrison ZA, Razvi E, Nitz M, Sheppard DC, Howell PL. Structural and functional analysis of Pseudomonas aeruginosa PelA provides insight into the modification of the Pel exopolysaccharide. J Biol Chem 2025; 301:108432. [PMID: 40120681 PMCID: PMC12022489 DOI: 10.1016/j.jbc.2025.108432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2025] [Revised: 03/14/2025] [Accepted: 03/18/2025] [Indexed: 03/25/2025] Open
Abstract
A major biofilm matrix determinant of Pseudomonas aeruginosa is the partially deacetylated α-1,4 linked N-acetylgalactosamine polymer, Pel. After synthesis and transport of the GalNAc polysaccharide across the inner membrane, PelA partially deacetylates and hydrolyzes Pel before its export out of the cell via PelB. While the Pel modification and export proteins are known to interact in the periplasm, it is unclear how the interaction of PelA and PelB coordinates these processes. To determine how PelA modifies the polymer, we determined its structure to 2.1 Å and found a unique arrangement of four distinct domains. We have shown previously that the hydrolase domain exhibits endo-α-1,4-N-acetylgalactosaminidase activity. Characterization of the deacetylase domain revealed that PelA is the founding member of a new carbohydrate esterase family, CE21. Further, we found that the PelAB interaction enhances the deacetylation of N-acetylgalactosamine oligosaccharides. Using the PelA structure in conjunction with AlphaFold2 modeling of the PelAB complex, we propose a model wherein PelB guides Pel to the deacetylase domain of PelA and subsequently to the porin domain of PelB for export. Perturbation or loss of the PelAB interaction would result in less efficient deacetylation and potentially increased Pel hydrolysis. In PelA homologs across many phyla, the predicted structure and active sites are conserved, suggesting a common modification mechanism in Gram-negative bacterial species containing a functional pel operon.
Collapse
Affiliation(s)
- Jaime C Van Loon
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - François Le Mauff
- Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, Quebec, Canada; Infectious Disease and Immunity in Global Health, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada; McGill Interdisciplinary Initiative in Infection and Immunity, Montreal, Quebec, Canada; GlycoNET Integrated Services, Microbial Glycomic Node, Montreal, Quebec, Canada
| | - Mario A Vargas
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stephanie Gilbert
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Roland Pfoh
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Zachary A Morrison
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Erum Razvi
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Mark Nitz
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Donald C Sheppard
- Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, Quebec, Canada; Infectious Disease and Immunity in Global Health, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada; McGill Interdisciplinary Initiative in Infection and Immunity, Montreal, Quebec, Canada
| | - P Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
3
|
Ma W, Huang Z, Zhang Y, Liu K, Li D, Liu Q. Interaction between inflammation and biofilm infection and advances in targeted biofilm therapy strategies. Microbiol Res 2025; 298:128199. [PMID: 40347631 DOI: 10.1016/j.micres.2025.128199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2024] [Revised: 04/25/2025] [Accepted: 04/27/2025] [Indexed: 05/14/2025]
Abstract
Biofilms are aggregates of bacteria, primarily regulated by quorum sensing (QS) and extracellular polymeric substances (EPS) mechanisms. Inflammation is the immune system's response to tissue damage and infection, which is regulated by a variety of cytokines and mediators. Bacterial biofilm intensified the development of inflammation, and inflammation of the microenvironment in turn promoted bacterial biofilm formation and diffusion, forming a positive feedback loop of "inflammation-biofilm", leading to the treatment-resistant of related infections. A deep understanding of the treatment of inflammatory and recalcitrant biofilm disease might offer important diagnostic and therapeutic perceptions. Therefore, this review summarizes the role of biofilm in different inflammatory diseases, and the complex interactions between bacterial biofilm infections and host inflammatory responses are emphasized. Finally, the current treatment methods for bacterial biofilm infection are also discussed, and specifically highlights biofilm infection treatments based on nanocomposite materials, aiming to provide insights and guidance for research and clinical management of biofilm-associated diseases.
Collapse
Affiliation(s)
- WenWen Ma
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, PR China
| | - ZhiQiang Huang
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, PR China
| | - Ye Zhang
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, PR China
| | - Kun Liu
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, PR China
| | - DeZhi Li
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, PR China
| | - Qing Liu
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, PR China.
| |
Collapse
|
4
|
Borisova D, Strateva T, Dimov SG, Atanassova B, Paunova-Krasteva T, Topouzova-Hristova T, Danova ST, Tropcheva R, Stoitsova S. Diversification of Pseudomonas aeruginosa After Inhaled Tobramycin Therapy of Cystic Fibrosis Patients: Genotypic and Phenotypic Characteristics of Paired Pre- and Post-Treatment Isolates. Microorganisms 2025; 13:730. [PMID: 40284567 PMCID: PMC12029236 DOI: 10.3390/microorganisms13040730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2025] [Revised: 03/19/2025] [Accepted: 03/20/2025] [Indexed: 04/29/2025] Open
Abstract
This study examines the impact of inhaled tobramycin therapy on the within-host changes in P. aeruginosa strains isolated from Bulgarian patients with CF prior to and post treatment. Genotypic comparison by RAPD-PCR indicated that most of the pre-treatment isolates had a high similarity and were genetically comparatively close to strains from other countries with known increased morbidity or treatment requirements. Most of the post-treatment isolates were, however, genetically distant from their pre-treatment counterparts, showing genotypic diversification after the treatment. Phenotypic comparisons showed a lower ODmax reached during groswth and an increased lag-time in the post-treatment isolates. All strains were capable of invasion and intracellular reproduction within A549 cultured cells. The addition of sub-inhibitory amounts (1/4 or 1/2 MIC) of tobramycin during growth showed the higher relative fitness (as a percentage of the untreated control) of the post-treatment strains. The effects of sub-MICs on biofilm growth did not show such a pronounced trend. However, when a resazurin-based viability test was applied, the advantage of the post-treatment strains was confirmed for both broth and biofilm cultures. In spite of that, according to the determined MIC values, all isolates were tobramycin-sensitive, and the data from this study imply the development of tolerance to the antibiotic in the strains that survived the treatment.
Collapse
Affiliation(s)
- Dayana Borisova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 25, 1113 Sofia, Bulgaria; (D.B.); (T.P.-K.); (S.T.D.)
| | - Tanya Strateva
- Department of Medical Microbiology “Corr. Mem. Prof. Ivan Mitov, MD, DMSc”, Faculty of Medicine, Medical University of Sofia, 2 Zdrave Str., 1431 Sofia, Bulgaria;
| | - Svetoslav G. Dimov
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria; (S.G.D.); (B.A.); (T.T.-H.)
| | - Borjana Atanassova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria; (S.G.D.); (B.A.); (T.T.-H.)
| | - Tsvetelina Paunova-Krasteva
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 25, 1113 Sofia, Bulgaria; (D.B.); (T.P.-K.); (S.T.D.)
| | - Tanya Topouzova-Hristova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria; (S.G.D.); (B.A.); (T.T.-H.)
| | - Svetla T. Danova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 25, 1113 Sofia, Bulgaria; (D.B.); (T.P.-K.); (S.T.D.)
| | - Rositsa Tropcheva
- Center of Applied Studies and Innovation, 8, Dragan Tsankov Blvd., 1164 Sofia, Bulgaria;
| | - Stoyanka Stoitsova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 25, 1113 Sofia, Bulgaria; (D.B.); (T.P.-K.); (S.T.D.)
| |
Collapse
|
5
|
Lew SQ, Chong SY, Lau GW. Modulation of pulmonary immune functions by the Pseudomonas aeruginosa secondary metabolite pyocyanin. Front Immunol 2025; 16:1550724. [PMID: 40196115 PMCID: PMC11973339 DOI: 10.3389/fimmu.2025.1550724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2024] [Accepted: 03/05/2025] [Indexed: 04/09/2025] Open
Abstract
Pseudomonas aeruginosa is a prevalent opportunistic Gram-negative bacterial pathogen. One of its key virulence factors is pyocyanin, a redox-active phenazine secondary metabolite that plays a crucial role in the establishment and persistence of chronic infections. This review provides a synopsis of the mechanisms through which pyocyanin exacerbates pulmonary infections. Pyocyanin induces oxidative stress by generating reactive oxygen and nitrogen species which disrupt essential defense mechanisms in respiratory epithelium. Pyocyanin increases airway barrier permeability and facilitates bacterial invasion. Pyocyanin also impairs mucociliary clearance by damaging ciliary function, resulting in mucus accumulation and airway obstruction. Furthermore, it modulates immune responses by promoting the production of pro-inflammatory cytokines, accelerating neutrophil apoptosis, and inducing excessive neutrophil extracellular trap formation, which exacerbates lung tissue damage. Additionally, pyocyanin disrupts macrophage phagocytic function, hindering the clearance of apoptotic cells and perpetuating inflammation. It also triggers mucus hypersecretion by inactivating the transcription factor FOXA2 and enhancing the IL-4/IL-13-STAT6 and EGFR-AKT/ERK1/2 signaling pathways, leading to goblet cell metaplasia and increased mucin production. Insights into the role of pyocyanin in P. aeruginosa infections may reveal potential therapeutic strategies to alleviate the severity of infections in chronic respiratory diseases including cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD).
Collapse
Affiliation(s)
| | | | - Gee W. Lau
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| |
Collapse
|
6
|
Byeon CH, Kinney T, Saricayir H, Holst Hansen K, Scott FJ, Srinivasa S, Wells MK, Mentink-Vigier F, Kim W, Akbey Ü. Ultrasensitive Characterization of Native Bacterial Biofilms via Dynamic Nuclear Polarization-Enhanced Solid-State NMR. Angew Chem Int Ed Engl 2025; 64:e202418146. [PMID: 39777964 PMCID: PMC11919551 DOI: 10.1002/anie.202418146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2024] [Revised: 12/27/2024] [Accepted: 01/07/2025] [Indexed: 01/11/2025]
Abstract
Bacterial biofilms are major contributors to persistent infections and antimicrobial resistance, posing significant challenges to treatment. However, obtaining high-resolution structural information on native bacterial biofilms has remained elusive due to the methodological limitations associated with analyzing complex biological samples. Solid-state NMR (ssNMR) has shown promise in this regard, but its conventional application is hindered by sensitivity constraints for unlabeled samples. In this study, we utilized high-sensitivity Dynamic Nuclear Polarization (DNP) ssNMR to characterize native Pseudomonas fluorescens colony biofilms. The ~75-fold sensitivity enhancement provided by DNP enabled structural characterization without isotope labeling or chemical/physical modification. We successfully collected 1D 13C/15N, and 2D 1H-13C, 1H-15N and 13C-13C ssNMR spectra within seconds, minutes or hours, facilitating the identification and quantification of biofilm extracellular matrix (ECM) components. Additionally, DNP ssNMR allowed quantitative detection of both flexible and rigid biofilm components by favorable freezing conditions. This study represents the first application of ultrasensitive DNP ssNMR to characterize a native bacterial biofilm, significantly expanding the capabilities of ssNMR for analyzing the composition and structure of a wide array of in vitro and ex vivo biofilms. The versatility of this approach will accelerate structure-guided efforts to combat infections caused by biofilm-forming microbes.
Collapse
Affiliation(s)
- Chang-Hyeock Byeon
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Ted Kinney
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Hakan Saricayir
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Kasper Holst Hansen
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
- Department of Biomedicine, Aarhus University, Aarhus, 8000, Denmark
| | - Faith J Scott
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Sadhana Srinivasa
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA, 15282, USA
| | - Meghan K Wells
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA, 15282, USA
| | - Frederic Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306, USA
| | - Wook Kim
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA, 15282, USA
| | - Ümit Akbey
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| |
Collapse
|
7
|
Panthi VK, Fairfull-Smith KE, Wells TJ, Wang T, Islam N. Ceftriaxone-Loaded Liposomal Nanoparticles for Pulmonary Delivery Against Lower Respiratory Tract Infections: Development and Characterization. Pharmaceuticals (Basel) 2025; 18:414. [PMID: 40143190 PMCID: PMC11945751 DOI: 10.3390/ph18030414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2025] [Revised: 03/11/2025] [Accepted: 03/11/2025] [Indexed: 03/28/2025] Open
Abstract
Background/Objectives: Herein, we demonstrate the development and characterization of ceftriaxone (CTX)-loaded liposomal nanoparticles (NPs) intended to be applicable to the management of lower respiratory tract infections (LRTIs) associated with resistant bacteria. Methods: The CTX-loaded liposomal NPs were fabricated by a thin film hydration approach. Results: The particle size of the NPs, determined by a Zetasizer, was within the range of 90-536 nm. Microscopic examination by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) revealed that particles are spherical in shape and have retained their original morphology even after freeze-drying. Attenuated total reflection-Fourier transform infrared (ATR-FTIR), differential scanning calorimetry (DSC), thermogravimetric (TG), and powder X-ray diffraction (PXRD) spectra exhibited that CTX is incorporated into the liposomes with no possible interaction between drug and excipients. The formation of the CTX-loaded liposomal NPs was dependent on the concentrations of phospholipids, cholesterol and mannitol; however, no considerable differences were observed in entrapment efficiency and loading capacity of CTX formulations (F6-F10). Using a twin-stage impinger (TSI), the in vitro aerosolization of the formulations were carried out at a flow rate of 60 ± 5 L/min and CTX was determined by a validated HPLC method and the prepared liposomal formulations produced promising fine particle fraction (FPF) between 47 and 62%. The prepared formulation (F6) showed prolonged CTX release of 94.0% ± 5.7 and 95.9% ± 3.9 at 24 h and 48 h, respectively. The drug release followed the Hixon-Crowell model, with CTX being transported through Fickian diffusion. Conclusions: These results highlight the prepared CTX-loaded inhaled liposomal formulation would be suitable for pulmonary delivery and extend the successful antibiotic delivery strategies for the effective management of LRTIs.
Collapse
Affiliation(s)
- Vijay Kumar Panthi
- Pharmacy Discipline, School of Clinical Sciences, Faculty of Health, Queensland University of Technology (QUT), Brisbane, QLD 4000, Australia;
| | - Kathryn E. Fairfull-Smith
- School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), Brisbane, QLD 4000, Australia;
- Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, QLD 4000, Australia
| | - Timothy J. Wells
- Frazer Institute, The University of Queensland, Brisbane, QLD 4102, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4001, Australia
| | - Tony Wang
- Central Analytical Research Facility, Research Portfolio, Queensland University of Technology (QUT), Brisbane, QLD 4000, Australia;
| | - Nazrul Islam
- Pharmacy Discipline, School of Clinical Sciences, Faculty of Health, Queensland University of Technology (QUT), Brisbane, QLD 4000, Australia;
- Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, QLD 4000, Australia
- Centre for Immunology and Infection Control (CIIC), Queensland University of Technology (QUT), Brisbane, QLD 4000, Australia
| |
Collapse
|
8
|
Reichhardt C, Matwichuk ML, Lewerke LT, Jacobs HM, Yan J, Parsek MR. Non-disruptive matrix turnover is a conserved feature of biofilm aggregate growth in paradigm pathogenic species. mBio 2025; 16:e0393524. [PMID: 39982068 PMCID: PMC11898600 DOI: 10.1128/mbio.03935-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2024] [Accepted: 01/23/2025] [Indexed: 02/22/2025] Open
Abstract
Bacteria form multicellular aggregates called biofilms. A crucial component of these aggregates is a protective matrix that holds the community together. Biofilm matrix composition varies depending upon bacterial species but typically includes exopolysaccharides (EPS), proteins, and extracellular DNA. Pseudomonas aeruginosa is a model organism for the study of biofilms, and in non-mucoid biofilms, it uses the structurally distinct EPS Psl and Pel, the EPS-binding protein CdrA, and eDNA as key matrix components. An interesting phenomenon that we and others have observed is that the periphery of a biofilm aggregate can be EPS-rich and contain very few cells. In this study, we investigated two possible models of assembly and dynamics of this EPS-rich peripheral region: (i) newly synthesized EPS is inserted and incorporated into the existing EPS-rich region at the periphery during biofilm aggregate growth or (ii) EPS is continuously turned over and newly synthesized EPS is deposited at the outermost edge of the aggregate. Our results support the latter model. Specifically, we observed that new EPS is continually deposited at the aggregate periphery, which is necessary for continued aggregate growth but not aggregate stability. We made similar observations in another paradigm biofilm-forming species, Vibrio cholerae. This pattern of deposition raises the question of how EPS is retained. Specifically, for P. aeruginosa biofilms, the matrix adhesin CdrA is thought to retain EPS. However, current thinking is that cell-associated CdrA is responsible for this retention, and it is not clear how CdrA might function in the relatively cell-free aggregate periphery. We observed that CdrA is enzymatically degraded during aggregate growth without negatively impacting biofilm stability and that cell-free CdrA can partially maintain aggregation and Psl retention. Overall, this study shows that the matrix of P. aeruginosa biofilms undergoes both continuous synthesis of matrix material and matrix turnover to accommodate biofilm aggregate growth and that cell-free matrix can at least partially maintain biofilm aggregation and EPS localization. Furthermore, our similar observations for V. cholerae biofilms suggest that our findings may represent basic principles of aggregate assembly in bacteria. IMPORTANCE Here, we show that, to accommodate growing cellular biomass, newly produced Psl is deposited over existing Psl at the periphery of biofilm aggregates. We demonstrated that V. cholerae employs a similar mechanism with its biofilm matrix EPS, VPS. In addition, we found that the protease LasB is present in the biofilm matrix, resulting in degradation of CdrA to lower molecular weight cell-free forms. We then show that the released forms of CdrA are retained in the matrix and remain functional. Together, our findings support that the P. aeruginosa biofilm matrix is dynamic during the course of aggregate growth and that other species may employ similar mechanisms to remodel their matrix.
Collapse
Affiliation(s)
- Courtney Reichhardt
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | | | - Lincoln T. Lewerke
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - Holly M. Jacobs
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - Jing Yan
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA
| | - Matthew R. Parsek
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| |
Collapse
|
9
|
Amier Y, Ji W, Xun Y, Yu X, Zhu Z, Rao J. pH-Responsive Protein-Polycation Nanocarriers for Efficient Eradication of Bacterial Biofilms and Intracellular Bacteria. Macromol Rapid Commun 2025; 46:e2400809. [PMID: 39555902 DOI: 10.1002/marc.202400809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2024] [Revised: 11/05/2024] [Indexed: 11/19/2024]
Abstract
Bacterial biofilms and intracellular pathogens pose significant challenges in eradication, often leading to persistent infections that are difficult to treat. To address this issue, the hydrophobic biofilm dispersant D-tyrosine is encapsulated within protein-polycation nanoparticles, designed using a mannose-terminated cationic polymer and concanavalin through electrostatic interactions. Thermodynamic studies reveal that free mannosyl groups on the nanoparticle surface promote spontaneous binding to receptor molecules mimicking those on bacterial biofilms and host cells. Under mildly acidic conditions, the nanoparticles reduce in size from 550 to ≈48 nm within 2 h, releasing 76% of encapsulated D-tyrosine. The combination of mannose targeting, particle size reduction, and controlled D-tyrosine release enable the nanoparticles to eliminate 70%-80% of the Pseudomonas aeruginosa and Staphylococcus aureus biofilm biomass at minimum bactericidal concentration (MBC) and 2MBC while eradicating 8 log of bacteria embedded within the biofilm. In an intracellular Pseudomonas aeruginosa infection model using RAW 264.7 macrophages, the nanoparticles at 2MBC eliminate over 95% of the intracellular bacteria without inducing an increase in the inflammatory cytokine interleukin-6. These protein-polycation nanoparticles, which activate their antimicrobial properties under acidic conditions, efficiently penetrate bacterial biofilms and host cell barriers via their mannose-rich surface, offering a promising strategy for the treatment of persistent infections.
Collapse
Affiliation(s)
- Yirixiatijiang Amier
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P. R. China
- State Key Laboratory of Materials Processing and Die & Mould Technology, and Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Wenke Ji
- State Key Laboratory of Materials Processing and Die & Mould Technology, and Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Yang Xun
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P. R. China
| | - Xiao Yu
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P. R. China
| | - Zhiyuan Zhu
- Taizhou Research Institute, Southern University of Science and Technology, Taizhou, Zhejiang, 318001, P. R. China
| | - Jingyi Rao
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P. R. China
- State Key Laboratory of Materials Processing and Die & Mould Technology, and Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| |
Collapse
|
10
|
Flemming HC, van Hullebusch ED, Little BJ, Neu TR, Nielsen PH, Seviour T, Stoodley P, Wingender J, Wuertz S. Microbial extracellular polymeric substances in the environment, technology and medicine. Nat Rev Microbiol 2025; 23:87-105. [PMID: 39333414 DOI: 10.1038/s41579-024-01098-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2024] [Indexed: 09/29/2024]
Abstract
Microbial biofilms exhibit a self-produced matrix of extracellular polymeric substances (EPS), including polysaccharides, proteins, extracellular DNA and lipids. EPS promote interactions of the biofilm with other cells and sorption of organics, metals and chemical pollutants, and they facilitate cell adhesion at interfaces and ensure matrix cohesion. EPS have roles in various natural environments, such as soils, sediments and marine habitats. In addition, EPS are relevant in technical environments, such as wastewater and drinking water treatment facilities, and water distribution systems, and they contribute to biofouling and microbially influenced corrosion. In medicine, EPS protect pathogens within the biofilm against the host immune system and antimicrobials, and emerging evidence suggests that EPS can represent potential virulence factors. By contrast, EPS yield a wide range of valuable products that include their role in self-repairing concrete. In this Review, we aim to explore EPS as a functional unit of biofilms in the environment, in technology and in medicine.
Collapse
Affiliation(s)
- Hans-Curt Flemming
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore.
- Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao, China.
| | | | | | - Thomas R Neu
- Department of River Ecology, Helmholtz Centre for Environmental Research - UFZ, Magdeburg, Germany
| | - Per H Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Thomas Seviour
- Aarhus University Centre for Water Technology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Paul Stoodley
- Department of Microbial Infection and Immunity and the Department of Orthopaedics, the Ohio State University, Columbus, OH, USA
- National Centre for Advanced Tribology at Southampton (nCATS), National Biofilm Innovation Centre (NBIC), Mechanical Engineering, University of Southampton, Southampton, UK
| | - Jost Wingender
- University of Duisburg-Essen, Faculty of Chemistry, Environmental Microbiology and Biotechnology, Essen, Germany
| | - Stefan Wuertz
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
| |
Collapse
|
11
|
Gannon AD, Matlack J, Darch SE. Exploring aggregation genes in a P. aeruginosa chronic infection model. J Bacteriol 2025; 207:e0042924. [PMID: 39660900 PMCID: PMC11784459 DOI: 10.1128/jb.00429-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2024] [Accepted: 10/28/2024] [Indexed: 12/12/2024] Open
Abstract
Bacterial aggregates are observed in both natural and artificial environments. In the context of disease, aggregates have been isolated from chronic and acute infections. Pseudomonas aeruginosa (Pa) aggregates contribute significantly to chronic infections, particularly in the lungs of people with cystic fibrosis (CF). Unlike the large biofilm structures observed in vitro, Pa in CF sputum forms smaller aggregates (~10-1,000 cells), and the mechanisms behind their formation remain underexplored. This study aims to identify genes essential and unique to Pa aggregate formation in a synthetic CF sputum media (SCFM2). We cultured Pa strain PAO1 in SCFM2 and LB, both with and without mucin, and used RNA sequencing (RNA-seq) to identify differentially expressed genes. The presence of mucin revealed 13 significantly differentially expressed (DE) genes, predominantly downregulated, with 40% encoding hypothetical proteins unique to aggregates. Using high-resolution microscopy, we assessed the ability of mutants to form aggregates. Notably, no mutant exhibited a completely planktonic phenotype. Instead, we identified multiple spatial phenotypes described as "normal," "entropic," or "impaired." Entropic mutants displayed tightly packed, raft-like structures, while impaired mutants had loosely packed cells. Predictive modeling linked the prioritized genes to metabolic shifts, iron acquisition, surface modification, and quorum sensing. Co-culture experiments with wild-type PAO1 revealed further spatial heterogeneity and the ability to "rescue" some mutant phenotypes, suggesting cooperative interactions during growth. This study enhances our understanding of Pa aggregate biology, specifically the genes and pathways unique to aggregation in CF-like environments. Importantly, it provides insights for developing therapeutic strategies targeting aggregate-specific pathways. IMPORTANCE This study identifies genes essential for the formation of Pseudomonas aeruginosa (Pa) aggregates in cystic fibrosis (CF) sputum, filling a critical gap in understanding their specific biology. Using a synthetic CF sputum model (SCFM2) and RNA sequencing, 13 key genes were identified, whose disruption led to distinct spatial phenotypes observed through high-resolution microscopy. The addition of wild-type cells either rescued the mutant phenotype or increased spatial heterogeneity, suggesting cooperative interactions are involved in aggregate formation. This research advances our knowledge of Pa aggregate biology, particularly the unique genes and pathways involved in CF-like environments, offering valuable insights for developing targeted therapeutic strategies against aggregate-specific pathways.
Collapse
Affiliation(s)
- Alexa D. Gannon
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Jenet Matlack
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA
| | - Sophie E. Darch
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| |
Collapse
|
12
|
Zubair M, Fatima F, Rahman S, Alrasheed T, Alatawy R, Mesaik MA. Disruption of Biofilm Formation by Dead Sea Soil Extracts: A Novel Approach Against Diabetic Foot Wound Isolates. MICROBIOLOGY RESEARCH 2024; 15:2535-2553. [DOI: 10.3390/microbiolres15040169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2025] Open
Abstract
Bacterial biofilms are closely associated with the rising threat of antimicrobial resistance, which is becoming a global concern. Recently, there has been increased interest in natural extracts as potential antimicrobial agents. One such extract is Dead Sea mud. While there is some evidence of its antimicrobial properties, it has not been extensively studied. Therefore, we designed a study to evaluate the potential of Dead Sea soil as an antimicrobial agent. For this purpose, three bacterial species (Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus) were isolated from the ulcerated foot of a patient in a hospital in Tabuk. P. aeruginosa exhibited significant antibiotic resistance, particularly to Levofloxacin (90%) and Tobramycin (80%), while S. aureus showed 70% resistance to Levofloxacin but no vancomycin resistance. Biofilm activity varied among bacterial strains, with P. aeruginosa showing 30% strong biofilm production. MIC values indicated resistance levels, with P. aeruginosa strain PA8 having the highest MIC at 650 µL/mL. All strains showed significant differences in exopolysaccharide (EPS) production at 0.25 × MIC (p ≤ 0.05) and 0.5 × MIC (p ≤ 0.005). Similarly, alginate production was significantly reduced at 0.25 × MIC (p ≤ 0.05), with even greater inhibition at 0.5 × MIC for combinations such as EC7 + SA5 (p ≤ 0.001). Hydrophobicity significantly changed at 0.25 × MIC (p ≤ 0.05), and combinations revealed highly significant reductions at 0.5 × MIC (p ≤ 0.001). Additionally, significant differences in outer membrane disruption were observed (p ≤ 0.05) with greater effects at 0.5 × MIC (p ≤ 0.005). Swarming motility was notably reduced for SA5 at 0.25 × MIC (p ≤ 0.05) and for PA2 at 0.5 × MIC (p ≤ 0.001). Chitinase activity showed greater reductions at 0.5 × MIC, with EC7 exhibiting the highest decrease. Lastly, sub-MIC concentrations enhanced reactive oxygen species (ROS) production, particularly for strains PA2 and SA5. Our results demonstrate the excellent potential of Dead Sea soil extract as an antimicrobial compound. Future studies should incorporate in vivo models to validate these findings clinically.
Collapse
Affiliation(s)
- Mohammad Zubair
- Department of Medical Microbiology, Faculty of Medicine, University of Tabuk, Tabuk 71491, Saudi Arabia
- Molecular Microbiology and Infectious Diseases Research Center, Faculty of Medicine, University of Tabuk, Tabuk 71491, Saudi Arabia
| | - Farha Fatima
- Department of Zoology, Faculty of Life Science, Aligarh Muslim University, Aligarh 202001, India
| | - Sumbul Rahman
- Department of Ilmul Advia, Faculty of Unani Medicine, Aligarh Muslim University, Aligarh 202001, India
| | - Tariq Alrasheed
- Department of Internal Medicine, Faculty of Medicine, University of Tabuk, Tabuk 71491, Saudi Arabia
| | - Roba Alatawy
- Department of Medical Microbiology, Faculty of Medicine, University of Tabuk, Tabuk 71491, Saudi Arabia
- Molecular Microbiology and Infectious Diseases Research Center, Faculty of Medicine, University of Tabuk, Tabuk 71491, Saudi Arabia
| | - M. Ahmed Mesaik
- Department of Medical Microbiology, Faculty of Medicine, University of Tabuk, Tabuk 71491, Saudi Arabia
- Molecular Microbiology and Infectious Diseases Research Center, Faculty of Medicine, University of Tabuk, Tabuk 71491, Saudi Arabia
| |
Collapse
|
13
|
Meirelles LA, Vayena E, Debache A, Schmidt E, Rossy T, Distler T, Hatzimanikatis V, Persat A. Pseudomonas aeruginosa faces a fitness trade-off between mucosal colonization and antibiotic tolerance during airway infection. Nat Microbiol 2024; 9:3284-3303. [PMID: 39455898 DOI: 10.1038/s41564-024-01842-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 09/27/2024] [Indexed: 10/28/2024]
Abstract
Pseudomonas aeruginosa frequently causes antibiotic-recalcitrant pneumonia, but the mechanisms driving its adaptation during human infections remain unclear. To reveal the selective pressures and adaptation strategies at the mucosal surface, here we investigated P. aeruginosa growth and antibiotic tolerance in tissue-engineered airways by transposon insertion sequencing (Tn-seq). Metabolic modelling based on Tn-seq data revealed the nutritional requirements for P. aeruginosa growth, highlighting reliance on glucose and lactate and varying requirements for amino acid biosynthesis. Tn-seq also revealed selection against biofilm formation during mucosal growth in the absence of antibiotics. Live imaging in engineered organoids showed that biofilm-dwelling cells remained sessile while colonizing the mucosal surface, limiting nutrient foraging and reduced growth. Conversely, biofilm formation increased antibiotic tolerance at the mucosal surface. Moreover, mutants with exacerbated biofilm phenotypes protected less tolerant but more cytotoxic strains, contributing to phenotypic heterogeneity. P. aeruginosa must therefore navigate conflicting physical and biological selective pressures to establish chronic infections.
Collapse
Affiliation(s)
- Lucas A Meirelles
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Evangelia Vayena
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Auriane Debache
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Eric Schmidt
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Tamara Rossy
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Tania Distler
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Vassily Hatzimanikatis
- Laboratory of Computational Systems Biotechnology, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Alexandre Persat
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| |
Collapse
|
14
|
Byeon CH, Hansen KH, DePas W, Akbey Ü. High-resolution 2D solid-state NMR provides insights into nontuberculous mycobacteria. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2024; 134:101970. [PMID: 39312837 DOI: 10.1016/j.ssnmr.2024.101970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 09/05/2024] [Accepted: 09/09/2024] [Indexed: 09/25/2024]
Abstract
We present a high-resolution magic-angle spinning (MAS) solid-state NMR (ssNMR) study to characterize nontuberculous mycobacteria (NTM). We studied two different NTM strains, Mycobacterium smegmatis, a model, non-pathogenic strain, and Mycobacterium abscessus, an emerging and important human pathogen. Hydrated NTM samples were studied at natural abundance without isotope-labelling, as whole-cells versus cell envelope isolates, and native versus fixed sample preparations. We utilized 1D13C and 2D 1H-13C ssNMR spectra and peak deconvolution to identify NTM cell-wall chemical sites. More than ∼100 distinct 13C signals were identified in the ssNMR spectra. We provide tentative assignments for ∼30 polysaccharides by using well resolved 1H/13C chemical shifts from the 2D INEPT-based 1H-13C ssNMR spectrum. The signals originating from both the flexible and rigid fractions of the whole-cell bacteria samples were selectively analyzed by utilizing either CP or INEPT based 13C ssNMR spectra. CP buildup curves provide insights into the dynamical similarity of the cell-wall components for NTM strains. Signals from peptidoglycan, arabinogalactan and mycolic acid were identified. The majority of the 13C signals were not affected by fixation of the whole cell samples. The isolated cell envelope NMR spectrum overlap with the whole-cell spectrum to a large extent, where the latter has more signals. As an orthogonal way of characterizing these bacteria, electron microscopy (EM) was used to provide spatial information. ssNMR and EM data suggest that the M. abscessus cell-wall is composed of a smaller peptidoglycan layer which is more flexible compared to M. smegmatis, which may be related to its higher pathogenicity. Here in this work, we used high-resolution 2D ssNMR first time to characterize NTM strains and identify chemical sites. These results will aid the development of structure-based approaches to combat NTM infections.
Collapse
Affiliation(s)
- Chang-Hyeock Byeon
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, 15261, United States
| | - Kasper Holst Hansen
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, 15261, United States
| | - William DePas
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, 15261, United States
| | - Ümit Akbey
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Pittsburgh, 15261, United States.
| |
Collapse
|
15
|
Coenye T, Ahonen M, Anderson S, Cámara M, Chundi P, Fields M, Foidl I, Gnimpieba EZ, Griffin K, Hinks J, Loka AR, Lushbough C, MacPhee C, Nater N, Raval R, Slater-Jefferies J, Teo P, Wilks S, Yung M, Biofilm Priority Questions Exercise Participants, Webb JS. Global challenges and microbial biofilms: Identification of priority questions in biofilm research, innovation and policy. Biofilm 2024; 8:100210. [PMID: 39221168 PMCID: PMC11364012 DOI: 10.1016/j.bioflm.2024.100210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 09/04/2024] Open
Abstract
Priority question exercises are increasingly used to frame and set future research, innovation and development agendas. They can provide an important bridge between the discoveries, data and outputs generated by researchers, and the information required by policy makers and funders. Microbial biofilms present huge scientific, societal and economic opportunities and challenges. In order to identify key priorities that will help to advance the field, here we review questions from a pool submitted by the international biofilm research community and from practitioners working across industry, the environment and medicine. To avoid bias we used computational approaches to group questions and manage a voting and selection process. The outcome of the exercise is a set of 78 unique questions, categorized in six themes: (i) Biofilm control, disruption, prevention, management, treatment (13 questions); (ii) Resistance, persistence, tolerance, role of aggregation, immune interaction, relevance to infection (10 questions); (iii) Model systems, standards, regulatory, policy education, interdisciplinary approaches (15 questions); (iv) Polymicrobial, interactions, ecology, microbiome, phage (13 questions); (v) Clinical focus, chronic infection, detection, diagnostics (13 questions); and (vi) Matrix, lipids, capsule, metabolism, development, physiology, ecology, evolution environment, microbiome, community engineering (14 questions). The questions presented are intended to highlight opportunities, stimulate discussion and provide focus for researchers, funders and policy makers, informing future research, innovation and development strategy for biofilms and microbial communities.
Collapse
Affiliation(s)
- Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Belgium
- ESCMID Study Group on Biofilms (ESGB), Basel, Switzerland
| | - Merja Ahonen
- Satakunta University of Applied Sciences, Finland
| | - Skip Anderson
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Miguel Cámara
- National Biofilms Innovation Centre, University of Nottingham Biodiscovery Institute, School of Life Sciences, University of Nottingham, Nottingham, UK
| | | | - Matthew Fields
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Ines Foidl
- National Biofilms Innovation Centre, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | | | - Kristen Griffin
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Jamie Hinks
- Nanyang Technological University, Singapore
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Singapore
| | | | | | - Cait MacPhee
- National Biofilms Innovation Centre, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Natasha Nater
- National Biofilms Innovation Centre, School of Biological Sciences, University of Southampton, Southampton, UK
| | - Rasmita Raval
- National Biofilms Innovation Centre, Open Innovation Hub for Antimicrobial Surfaces, Department of Chemistry, University of Liverpool, Liverpool, UK
| | - Jo Slater-Jefferies
- National Biofilms Innovation Centre, School of Biological Sciences, University of Southampton, Southampton, UK
| | - Pauline Teo
- Nanyang Technological University, Singapore
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Singapore
| | - Sandra Wilks
- National Biofilms Innovation Centre, School of Biological Sciences, University of Southampton, Southampton, UK
| | - Maria Yung
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Singapore
| | | | - Jeremy S. Webb
- National Biofilms Innovation Centre, School of Biological Sciences, University of Southampton, Southampton, UK
| |
Collapse
|
16
|
Vargas-Cuebas GG, Sanchez CA, Bezold EL, Walker GM, Siddiqui S, Minbiole KP, Wuest WM. Adaptations to cationic biocide exposure differentially influence virulence factors and pathogenicity in Pseudomonas aeruginosa. Virulence 2024; 15:2397503. [PMID: 39282885 PMCID: PMC11407422 DOI: 10.1080/21505594.2024.2397503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 05/09/2024] [Accepted: 07/24/2024] [Indexed: 09/19/2024] Open
Abstract
Cationic biocides (CBs), which include quaternary ammonium compounds (QACs), are employed to mitigate the spread of infectious bacteria, but resistance to such surface disinfectants is rising. CB exposure can have profound phenotypic implications that extend beyond allowing microorganisms to persist on surfaces. Pseudomonas aeruginosa is a deadly bacterial pathogen that is intrinsically tolerant to a wide variety of antimicrobials and is commonly spread in healthcare settings. In this study, we pursued resistance selection assays to the QAC benzalkonium chloride and quaternary phosphonium compound P6P-10,10 to assess the phenotypic effects of CB exposure in P. aeruginosa PAO1 and four genetically diverse, drug-resistant clinical isolates. In particular, we sought to examine how CB exposure affects defensive strategies and the virulence-associated "offensive" strategies in P. aeruginosa. We demonstrated that development of resistance to BAC is associated with increased production of virulence-associated pigments and alginate as well as pellicle formation. In an in vivo infection model, CB-resistant PAO1 exhibited a decreased level of virulence compared to wild type, potentially due to an observed fitness cost in these strains. Taken together, these results illustrate the significant consequence CB resistance exerts on the virulence-associated phenotypes of P. aeruginosa.
Collapse
Affiliation(s)
- Germán G. Vargas-Cuebas
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
| | | | | | | | | | | | | |
Collapse
|
17
|
Duong K, Moss E, Reichhardt C. Solid-state NMR compositional analysis of sputum from people with cystic fibrosis. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2024; 134:101975. [PMID: 39489104 DOI: 10.1016/j.ssnmr.2024.101975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 09/12/2024] [Accepted: 10/24/2024] [Indexed: 11/05/2024]
Abstract
People with the genetic disease cystic fibrosis (CF) often have chronic airway infections and produce airway secretions called sputum. A better understanding of sputum composition is desired in order to track changes in response to CF therapeutics and to improve laboratory models for the study of CF airway infections. The glycosylated protein mucin is a primary component. Along with extracellular DNA, mucin gives rise to the high viscoelasticity of sputum, which inhibits airway clearance and is thought to promote chronic airway infections in people with CF. Past studies of sputum composition identified additional biomolecular components of sputum including other proteins, both glycosylated and not glycosylated, free amino acids, and lipids. Typically, studies of sputum, as well as other complex biological materials, have focused on soluble or isolated components. Solid-state NMR is not limited to the study of soluble components. Instead, it can provide molecular-level information about insoluble biological samples. Additionally, solid-state NMR can provide information about sample composition without requiring any processing of the sample, eliminating the possibility of misestimating certain components due to insolubility or potential sample loss in isolation steps. In this study, we used both 13C and 31P CPMAS to investigate the total composition of sputum samples obtained from six people with CF. We compared these spectra to those of commercially available mucin, DNA, and phospholipid samples. Lastly, we performed complementary biochemical analyses to identify specific proteins present in the sputum samples. Overall, our findings provide insight into the composition of unprocessed sputum samples from people with CF, which can be used as a benchmark for future investigations of CF and infections in the airways of people with CF. Further, this study provides opportunities to expand the solid-state NMR approach to include dynamic nuclear polarization (DNP) to obtain high-resolution information of sputum and similar biological samples that are not feasible to isotopically enrich.
Collapse
Affiliation(s)
- Kathy Duong
- Department of Chemistry, Washington University, St. Louis, MO, 63130, United States
| | - Evan Moss
- Department of Chemistry, Washington University, St. Louis, MO, 63130, United States
| | - Courtney Reichhardt
- Department of Chemistry, Washington University, St. Louis, MO, 63130, United States.
| |
Collapse
|
18
|
Barclay AM, Ninaber DK, Limpens RWL, Walburg KV, Bárcena M, Hiemstra PS, Ottenhoff TH, van der Does AM, Joosten SA. Mycobacteria develop biofilms on airway epithelial cells and promote mucosal barrier disruption. iScience 2024; 27:111063. [PMID: 39502292 PMCID: PMC11536035 DOI: 10.1016/j.isci.2024.111063] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 08/14/2024] [Accepted: 09/25/2024] [Indexed: 11/08/2024] Open
Abstract
Tuberculosis displays several features commonly linked to biofilm-associated infections, including recurrence of infection and resistance to antibiotic treatment. The respiratory epithelium represents the first line of defense against pathogens such as Mycobacterium tuberculosis (Mtb). Here, we use an air-liquid interface model of human primary bronchial epithelial cells (PBEC) to explore the capability of four species of mycobacteria (Mtb, M. bovis (BCG), M. avium, and M. smegmatis) to form biofilms on airway epithelial cells. Mtb, BCG, and M. smegmatis consistently formed biofilms with extracellular matrixes on PBEC cultures. Biofilms varied in biomass, matrix polysaccharide content, and bacterial metabolic activity between species. Exposure of PBEC to mycobacteria caused the disruption of the epithelial barrier and was accompanied by mostly apical non-apoptotic cell death. Structural analysis revealed pore-like structures in 7-day biofilms. Taken together, mycobacteria can form biofilms on human airway epithelial cells, and long-term infection negatively affects barrier function and promotes cell death.
Collapse
Affiliation(s)
- Amy M. Barclay
- Leiden University Center for Infectious Diseases, (LUCID), Leiden University Medical Center, Leiden, the Netherlands
| | - Dennis K. Ninaber
- PulmoScience Lab, Department of Pulmonology, Leiden University Medical Center, Leiden, the Netherlands
| | - Ronald W.A. L. Limpens
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Kimberley V. Walburg
- Leiden University Center for Infectious Diseases, (LUCID), Leiden University Medical Center, Leiden, the Netherlands
| | - Montserrat Bárcena
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Pieter S. Hiemstra
- PulmoScience Lab, Department of Pulmonology, Leiden University Medical Center, Leiden, the Netherlands
| | - Tom H.M. Ottenhoff
- Leiden University Center for Infectious Diseases, (LUCID), Leiden University Medical Center, Leiden, the Netherlands
| | - Anne M. van der Does
- PulmoScience Lab, Department of Pulmonology, Leiden University Medical Center, Leiden, the Netherlands
| | - Simone A. Joosten
- Leiden University Center for Infectious Diseases, (LUCID), Leiden University Medical Center, Leiden, the Netherlands
| |
Collapse
|
19
|
Higgs MG, Greenwald MA, Roca C, Macdonald JK, Sidders AE, Conlon BP, Wolfgang MC. Flagellar motility and the mucus environment influence aggregation mediated antibiotic tolerance of Pseudomonas aeruginosa in chronic lung infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.10.25.620240. [PMID: 39484600 PMCID: PMC11527127 DOI: 10.1101/2024.10.25.620240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/03/2024]
Abstract
Pseudomonas aeruginosa frequently causes chronic lung infection in individuals with muco-obstructive airway diseases (MADs). Chronic P. aeruginosa infections are difficult to treat, primarily owing to antibiotic treatment failure, which is often observed in the absence of antimicrobial resistance. In MADs, P. aeruginosa forms biofilm-like aggregates within the luminal mucus. While the contribution of mucin hyperconcentration towards antibiotic tolerance has been described, the mechanism for mucin driven antibiotic tolerance and the influence of aggregates have not been fully elucidated. In this study, we investigated the contribution of flagellar motility towards aggregate formation as it relates to the diseased mucus environment. We found that loss of flagellar motility resulted in increased P. aeruginosa aggregation and tolerance to multiple classes of antibiotics. Further, we observed differential roles in antimicrobial tolerance of the motAB and motCD stators, which power the flagellum. Additionally, we found that control of fliC expression was important for aggregate formation and antibiotic tolerance as a strain constitutively expressing fliC was unable to form aggregates and was highly susceptible to treatment. Lastly, we demonstrate that neutrophil elastase, an abundant immune mediator and biomarker of chronic lung infection, promotes aggregation and antibiotic tolerance by impairing flagellar motility. Collectively, these results highlight the key role of flagellar motility in aggregate formation and antibiotic tolerance and deepens our understanding of how the MADs lung environment promotes antibiotic tolerance of P. aeruginosa.
Collapse
Affiliation(s)
- Matthew G. Higgs
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Matthew A. Greenwald
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Cristian Roca
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Jade K. Macdonald
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Ashelyn E. Sidders
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Brian P. Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Matthew C. Wolfgang
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| |
Collapse
|
20
|
Byeon CH, Kinney T, Saricayir H, Hansen KH, Scott F, Srinivasa S, Wells MK, Mentink-Vigier F, Kim W, Akbey Ü. High-Sensitivity Analysis of Native Bacterial Biofilms Using Dynamic Nuclear Polarization-Enhanced Solid-State NMR. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.25.614951. [PMID: 39386544 PMCID: PMC11463664 DOI: 10.1101/2024.09.25.614951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/12/2024]
Abstract
Bacterial biofilms cause persistent infections that are difficult to treat and contribute greatly to antimicrobial resistance. However, high-resolution structural information on native bacterial biofilms remain very limited. This limitation is primarily due to methodological constraints associated with analyzing complex native samples. Although solid-state NMR (ssNMR) is a promising method in this regard, its conventional applications typically suffer from sensitivity limitations, particularly for unlabeled native samples. Through the use of Dynamic Nuclear Polarization (DNP), we applied sensitivity enhanced ssNMR to characterize native Pseudomonas fluorescens colony biofilms. The increased ssNMR sensitivity by DNP enabled ultrafast structural characterization of the biofilm samples without isotope-labelling, and chemical or physical modification. We collected 1D 13 C and 15 N, and 2D 1 H- 13 C, 1 H- 15 N and 13 C- 13 C ssNMR spectra within seconds/minutes or hours, respectively which enabled us to identify biofilm components as polysaccharides, proteins, and eDNA effectively. This study represents the first application of ultrasensitive DNP ssNMR to characterize a native bacterial biofilm and expands the technical scope of ssNMR towards obtaining insights into the composition and structure of a wide array of in vitro and ex vivo biofilm applications. Such versatility should greatly boost efforts to develop structure-guided approaches for combating infections caused by biofilm-forming microbes.
Collapse
|
21
|
Ledger EL, Smith DJ, Teh JJ, Wood ME, Whibley PE, Morrison M, Goldberg JB, Reid DW, Wells TJ. Impact of CFTR Modulation on Pseudomonas aeruginosa Infection in People With Cystic Fibrosis. J Infect Dis 2024; 230:e536-e547. [PMID: 38442240 PMCID: PMC11420785 DOI: 10.1093/infdis/jiae051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/29/2024] [Indexed: 03/07/2024] Open
Abstract
BACKGROUND Pseudomonas aeruginosa is a multidrug-resistant pathogen causing recalcitrant pulmonary infections in people with cystic fibrosis (pwCF). Cystic fibrosis transmembrane conductance regulator (CFTR) modulators have been developed that partially correct the defective chloride channel driving disease. Despite the many clinical benefits, studies in adults have demonstrated that while P. aeruginosa sputum load decreases, chronic infection persists. Here, we investigate how P. aeruginosa in pwCF may change in the altered lung environment after CFTR modulation. METHODS P. aeruginosa strains (n = 105) were isolated from the sputum of 11 chronically colonized pwCF at baseline and up to 21 months posttreatment with elexacaftor-tezacaftor-ivacaftor or tezacaftor-ivacaftor. Phenotypic characterization and comparative genomics were performed. RESULTS Clonal lineages of P. aeruginosa persisted after therapy, with no evidence of displacement by alternative strains. We identified commonly mutated genes among patient isolates that may be positively selected for in the CFTR-modulated lung. However, classic chronic P. aeruginosa phenotypes such as mucoid morphology were sustained, and isolates remained just as resistant to clinically relevant antibiotics. CONCLUSIONS Despite the clinical benefits of CFTR modulators, clonal lineages of P. aeruginosa persist that may prove just as difficult to manage in the future, especially in pwCF with advanced lung disease.
Collapse
Affiliation(s)
- Emma L Ledger
- Frazer Institute, Faculty of Medicine, The University of Queensland, Brisbane, Australia
| | - Daniel J Smith
- Northside Clinical Unit, The University of Queensland, Brisbane, Australia
- Adult Cystic Fibrosis Centre, The Prince Charles Hospital, Brisbane, Australia
| | - Jing Jie Teh
- Frazer Institute, Faculty of Medicine, The University of Queensland, Brisbane, Australia
| | - Michelle E Wood
- Adult Cystic Fibrosis Centre, The Prince Charles Hospital, Brisbane, Australia
| | - Page E Whibley
- Adult Cystic Fibrosis Centre, The Prince Charles Hospital, Brisbane, Australia
| | - Mark Morrison
- Frazer Institute, Faculty of Medicine, The University of Queensland, Brisbane, Australia
- Australian Infectious Diseases Research Centre, Brisbane, Australia
| | - Joanna B Goldberg
- Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, Georgia, USA
| | - David W Reid
- Northside Clinical Unit, The University of Queensland, Brisbane, Australia
- Australian Infectious Diseases Research Centre, Brisbane, Australia
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Timothy J Wells
- Frazer Institute, Faculty of Medicine, The University of Queensland, Brisbane, Australia
- Australian Infectious Diseases Research Centre, Brisbane, Australia
| |
Collapse
|
22
|
Mishra A, Tabassum N, Aggarwal A, Kim YM, Khan F. Artificial Intelligence-Driven Analysis of Antimicrobial-Resistant and Biofilm-Forming Pathogens on Biotic and Abiotic Surfaces. Antibiotics (Basel) 2024; 13:788. [PMID: 39200087 PMCID: PMC11351874 DOI: 10.3390/antibiotics13080788] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2024] [Revised: 08/14/2024] [Accepted: 08/19/2024] [Indexed: 09/01/2024] Open
Abstract
The growing threat of antimicrobial-resistant (AMR) pathogens to human health worldwide emphasizes the need for more effective infection control strategies. Bacterial and fungal biofilms pose a major challenge in treating AMR pathogen infections. Biofilms are formed by pathogenic microbes encased in extracellular polymeric substances to confer protection from antimicrobials and the host immune system. Biofilms also promote the growth of antibiotic-resistant mutants and latent persister cells and thus complicate therapeutic approaches. Biofilms are ubiquitous and cause serious health risks due to their ability to colonize various surfaces, including human tissues, medical devices, and food-processing equipment. Detection and characterization of biofilms are crucial for prompt intervention and infection control. To this end, traditional approaches are often effective, yet they fail to identify the microbial species inside biofilms. Recent advances in artificial intelligence (AI) have provided new avenues to improve biofilm identification. Machine-learning algorithms and image-processing techniques have shown promise for the accurate and efficient detection of biofilm-forming microorganisms on biotic and abiotic surfaces. These advancements have the potential to transform biofilm research and clinical practice by allowing faster diagnosis and more tailored therapy. This comprehensive review focuses on the application of AI techniques for the identification of biofilm-forming pathogens in various industries, including healthcare, food safety, and agriculture. The review discusses the existing approaches, challenges, and potential applications of AI in biofilm research, with a particular focus on the role of AI in improving diagnostic capacities and guiding preventative actions. The synthesis of the current knowledge and future directions, as described in this review, will guide future research and development efforts in combating biofilm-associated infections.
Collapse
Affiliation(s)
- Akanksha Mishra
- School of Bioengineering and Biosciences, Lovely Professional University, Phagwara 144001, Punjab, India;
| | - Nazia Tabassum
- Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; (N.T.); (Y.-M.K.)
- Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea
| | - Ashish Aggarwal
- School of Bioengineering and Biosciences, Lovely Professional University, Phagwara 144001, Punjab, India;
| | - Young-Mog Kim
- Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; (N.T.); (Y.-M.K.)
- Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea
- Department of Food Science and Technology, Pukyong National University, Busan 48513, Republic of Korea
| | - Fazlurrahman Khan
- Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; (N.T.); (Y.-M.K.)
- Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea
- Institute of Fisheries Science, Pukyong National University, Busan 48513, Republic of Korea
- International Graduate Program of Fisheries Science, Pukyong National University, Busan 48513, Republic of Korea
| |
Collapse
|
23
|
Cojocaru E, Petriș OR, Cojocaru C. Nanoparticle-Based Drug Delivery Systems in Inhaled Therapy: Improving Respiratory Medicine. Pharmaceuticals (Basel) 2024; 17:1059. [PMID: 39204164 PMCID: PMC11357421 DOI: 10.3390/ph17081059] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Revised: 08/03/2024] [Accepted: 08/09/2024] [Indexed: 09/03/2024] Open
Abstract
Inhaled nanoparticle (NP) therapy poses intricate challenges in clinical and pharmacodynamic realms. Recent strides have revolutionized NP technology by enabling the incorporation of diverse molecules, thus circumventing systemic clearance mechanisms and enhancing drug effectiveness while mitigating systemic side effects. Despite the established success of systemic NP delivery in oncology and other disciplines, the exploration of inhaled NP therapies remains relatively nascent. NPs loaded with bronchodilators or anti-inflammatory agents exhibit promising potential for precise distribution throughout the bronchial tree, offering targeted treatment for respiratory diseases. This article conducts a comprehensive review of NP applications in respiratory medicine, highlighting their merits, ranging from heightened stability to exacting lung-specific delivery. It also explores cutting-edge technologies optimizing NP-loaded aerosol systems, complemented by insights gleaned from clinical trials. Furthermore, the review examines the current challenges and future prospects in NP-based therapies. By synthesizing current data and perspectives, the article underscores the transformative promise of NP-mediated drug delivery in addressing chronic conditions such as chronic obstructive pulmonary disease, a pressing global health concern ranked third in mortality rates. This overview illuminates the evolving landscape of NP inhalation therapies, presenting optimistic avenues for advancing respiratory medicine and improving patient outcomes.
Collapse
Affiliation(s)
- Elena Cojocaru
- Morpho-Functional Sciences II Department, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania;
| | - Ovidiu Rusalim Petriș
- Medical II Department, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Cristian Cojocaru
- Medical III Department, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania;
| |
Collapse
|
24
|
Walsh D, Parmenter C, Bakker SE, Lithgow T, Traven A, Harrison F. A new model of endotracheal tube biofilm identifies combinations of matrix-degrading enzymes and antimicrobials able to eradicate biofilms of pathogens that cause ventilator-associated pneumonia. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001480. [PMID: 39088248 PMCID: PMC11541551 DOI: 10.1099/mic.0.001480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 07/04/2024] [Indexed: 08/02/2024]
Abstract
Ventilator-associated pneumonia is defined as pneumonia that develops in a patient who has been on mechanical ventilation for more than 48 hours through an endotracheal tube. It is caused by biofilm formation on the indwelling tube, which introduces pathogenic microbes such as Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans into the patient's lower airways. Currently, there is a lack of accurate in vitro models of ventilator-associated pneumonia development. This greatly limits our understanding of how the in-host environment alters pathogen physiology and the efficacy of ventilator-associated pneumonia prevention or treatment strategies. Here, we showcase a reproducible model that simulates the biofilm formation of these pathogens in a host-mimicking environment and demonstrate that the biofilm matrix produced differs from that observed in standard laboratory growth medium. In our model, pathogens are grown on endotracheal tube segments in the presence of a novel synthetic ventilated airway mucus medium that simulates the in-host environment. Matrix-degrading enzymes and cryo-scanning electron microscopy were employed to characterize the system in terms of biofilm matrix composition and structure, as compared to standard laboratory growth medium. As seen in patients, the biofilms of ventilator-associated pneumonia pathogens in our model either required very high concentrations of antimicrobials for eradication or could not be eradicated. However, combining matrix-degrading enzymes with antimicrobials greatly improved the biofilm eradication of all pathogens. Our in vitro endotracheal tube model informs on fundamental microbiology in the ventilator-associated pneumonia context and has broad applicability as a screening platform for antibiofilm measures including the use of matrix-degrading enzymes as antimicrobial adjuvants.
Collapse
Affiliation(s)
- Dean Walsh
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Chris Parmenter
- Nanoscale and Microscale Research Centre, University of Nottingham, Nottingham, UK
| | | | - Trevor Lithgow
- Department of Biochemistry and Molecular Biology, Infection Program, Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
- Center To Impact AMR, Monash University, Clayton 3800, Victoria, Australia
| | - Ana Traven
- Department of Biochemistry and Molecular Biology, Infection Program, Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
- Center To Impact AMR, Monash University, Clayton 3800, Victoria, Australia
| | - Freya Harrison
- School of Life Sciences, University of Warwick, Coventry, UK
| |
Collapse
|
25
|
Schneier A, Melaugh G, Sadler JC. Engineered plastic-associated bacteria for biodegradation and bioremediation. BIOTECHNOLOGY FOR THE ENVIRONMENT 2024; 1:7. [PMID: 39026535 PMCID: PMC11256910 DOI: 10.1186/s44314-024-00007-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 04/29/2024] [Indexed: 07/20/2024]
Abstract
The global plastic waste crisis has triggered the development of novel methods for removal of recalcitrant polymers from the environment. Biotechnological approaches have received particular attention due to their potential for enabling sustainable, low-intensity bioprocesses which could also be interfaced with microbial upcycling pathways to support the emerging circular bioeconomy. However, low biodegradation efficiency of solid plastic materials remains a bottleneck, especially at mesophilic conditions required for one-pot degradation and upcycling. A promising strategy used in nature to address this is localisation of plastic-degrading microbes to the plastic surface via biofilm-mediated surface association. This review highlights progress and opportunities in leveraging these naturally occurring mechanisms of biofilm formation and other cell-surface adhesion biotechnologies to co-localise engineered cells to plastic surfaces. We further discuss examples of combining these approaches with extracellular expression of plastic-degrading enzymes to accelerate plastic degradation. Additionally, we review this topic in the context of nano- and microplastics bioremediation and their removal from wastewater and finally propose future research directions for this nascent field.
Collapse
Affiliation(s)
- Arianna Schneier
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Roger Land Building, Alexander Crum Brown Road, King’s Buildings, Edinburgh, EH9 3FF UK
| | - Gavin Melaugh
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD UK
- School of Engineering, University of Edinburgh, Edinburgh, EH9 3JL UK
| | - Joanna C. Sadler
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Roger Land Building, Alexander Crum Brown Road, King’s Buildings, Edinburgh, EH9 3FF UK
| |
Collapse
|
26
|
Edvardsen PKT, Askarian F, Zurich R, Nizet V, Vaaje-Kolstad G. Exploring roles of the chitinase ChiC in modulating Pseudomonas aeruginosa virulence phenotypes. Microbiol Spectr 2024; 12:e0054624. [PMID: 38819151 PMCID: PMC11218509 DOI: 10.1128/spectrum.00546-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 04/23/2024] [Indexed: 06/01/2024] Open
Abstract
Chitinases are ubiquitous enzymes involved in biomass degradation and chitin turnover in nature. Pseudomonas aeruginosa (PA), an opportunistic human pathogen, expresses ChiC, a secreted glycoside hydrolase 18 family chitinase. Despite speculation about ChiC's role in PA disease pathogenesis, there is scant evidence supporting this hypothesis. Since PA cannot catabolize chitin, we investigated the potential function(s) of ChiC in PA pathophysiology. Our findings show that ChiC exhibits activity against both insoluble (α- and β-chitin) and soluble chitooligosaccharides. Enzyme kinetics toward (GlcNAc)4 revealed a kcat of 6.50 s-1 and a KM of 1.38 mM, the latter remarkably high for a canonical chitinase. In our label-free proteomics investigation, ChiC was among the most abundant proteins in the Pel biofilm, suggesting a potential contribution to PA biofilm formation. Using an intratracheal challenge model of PA pneumonia, the chiC::ISphoA/hah transposon insertion mutant paradoxically showed slightly increased virulence compared to the wild-type parent strain. Our results indicate that ChiC is a genuine chitinase that contributes to a PA pathoadaptive pathway.IMPORTANCEIn addition to performing chitin degradation, chitinases from the glycoside hydrolase 18 family have been found to play important roles during pathogenic bacterial infection. Pseudomonas aeruginosa is an opportunistic pathogen capable of causing pneumonia in immunocompromised individuals. Despite not being able to grow on chitin, the bacterium produces a chitinase (ChiC) with hitherto unknown function. This study describes an in-depth characterization of ChiC, focusing on its potential contribution to the bacterium's disease-causing ability. We demonstrate that ChiC can degrade both polymeric chitin and chitooligosaccharides, and proteomic analysis of Pseudomonas aeruginosa biofilm revealed an abundance of ChiC, hinting at a potential role in biofilm formation. Surprisingly, a mutant strain incapable of ChiC production showed higher virulence than the wild-type strain. While ChiC appears to be a genuine chitinase, further investigation is required to fully elucidate its contribution to Pseudomonas aeruginosa virulence, an important task given the evident health risk posed by this bacterium.
Collapse
Affiliation(s)
| | - Fatemeh Askarian
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, UC San Diego School of Medicine, La Jolla, California, USA
| | - Raymond Zurich
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, UC San Diego School of Medicine, La Jolla, California, USA
| | - Victor Nizet
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, UC San Diego School of Medicine, La Jolla, California, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, California, USA
| | - Gustav Vaaje-Kolstad
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| |
Collapse
|
27
|
Liu W, Wang Y, Sun Y, Xia W, Qian X, Bo R, Huang Y, Ruan X. Baicalein inhibits biofilm formation of avian pathogenic Escherichia coli in vitro mainly by affecting adhesion. Res Vet Sci 2024; 174:105291. [PMID: 38729095 DOI: 10.1016/j.rvsc.2024.105291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 04/20/2024] [Accepted: 05/05/2024] [Indexed: 05/12/2024]
Abstract
Avian pathogenic Escherichia coli (APEC) is a widespread bacterium that causes significant economic losses to the poultry industry. APEC biofilm formation may result in chronic, persistent, and recurrent infections in clinics, making treatment challenging. Baicalein is a natural product that exhibits antimicrobial and antibiofilm activities. This study investigates the inhibitory effect of baicalein on APEC biofilm formation at different stages. The minimum inhibitory concentration (MIC) of baicalein on APEC was determined, and the growth curve of APEC biofilm formation was determined. The effects of baicalein on APEC biofilm adhesion, accumulation, and maturation were observed using optical microscopy, confocal laser scanning microscopy, and scanning electron microscopy. The biofilm inhibition rate of baicalein was calculated at different stages. The MIC of baicalein against APEC was 256 μg/mL. The process of APEC biofilm maturation takes approximately 48 h after incubation, with initial adhesion completed at 12 h, and cell accumulation finished at 24 h. Baicalein had a significant inhibitory effect on APEC biofilm formation at concentrations above 1 μg/mL (p < 0.01). Notably, baicalein had the highest rate of biofilm formation inhibition when added at the adhesion stage. Therefore, it can be concluded that baicalein is a potent inhibitor of APEC biofilm formation in vitro and acts, primarily by inhibiting cell adhesion. These findings suggests that baicalein has a potential application for inhibiting APEC biofilm formation and provides a novel approach for the prevention and control APEC-related diseases.
Collapse
Affiliation(s)
- Wanru Liu
- Laboratory of Veterinary Pharmacology and Toxicology, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, China
| | - Yufang Wang
- Laboratory of Veterinary Pharmacology and Toxicology, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, China
| | - Ying Sun
- Laboratory of Veterinary Pharmacology and Toxicology, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, China
| | - Wenjie Xia
- Laboratory of Veterinary Pharmacology and Toxicology, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, China
| | - Xiaoyue Qian
- Laboratory of Veterinary Pharmacology and Toxicology, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, China
| | - Ruihong Bo
- Laboratory of Veterinary Pharmacology and Toxicology, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, China
| | - Yuanyuan Huang
- Laboratory of Veterinary Pharmacology and Toxicology, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, China
| | - Xiangchun Ruan
- Laboratory of Veterinary Pharmacology and Toxicology, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, China; Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Hefei, Anhui Province 230036, China.
| |
Collapse
|
28
|
Grassi L, Asfahl KL, Van den Bossche S, Maenhout I, Sass A, Vande Weygaerde Y, Van Braeckel E, Verhasselt B, Boelens J, Tunney MM, Dandekar AA, Coenye T, Crabbé A. Antibiofilm activity of Prevotella species from the cystic fibrosis lung microbiota against Pseudomonas aeruginosa. Biofilm 2024; 7:100206. [PMID: 38975276 PMCID: PMC11225020 DOI: 10.1016/j.bioflm.2024.100206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 05/06/2024] [Accepted: 06/06/2024] [Indexed: 07/09/2024] Open
Abstract
It is increasingly recognized that interspecies interactions may modulate the pathogenicity of Pseudomonas aeruginosa during chronic lung infections. Nevertheless, while the interaction between P. aeruginosa and pathogenic microorganisms co-infecting the lungs has been widely investigated, little is known about the influence of other members of the lung microbiota on the infection process. In this study, we focused on investigating the impact of Prevotella species isolated from the sputum of people with cystic fibrosis (pwCF) on biofilm formation and virulence factor production by P. aeruginosa. Screening of a representative collection of Prevotella species recovered from clinical samples showed that several members of this genus (8 out 10 isolates) were able to significantly reduce biofilm formation of P. aeruginosa PAO1, without impact on growth. Among the tested isolates, the strongest biofilm-inhibitory activity was observed for Prevotella intermedia and Prevotella nigrescens, which caused a reduction of up to 90% in the total biofilm biomass of several P. aeruginosa isolates from pwCF. In addition, a strain-specific effect of P. nigrescens on the ability of P. aeruginosa to produce proteases and pyocyanin was observed, with significant alterations in the levels of these virulence factors detected in LasR mutant strains. Overall, these results suggest that non-pathogenic bacteria from the lung microbiota may regulate pathogenicity traits of P. aeruginosa, and possibly affect the outcome of chronic lung infections.
Collapse
Affiliation(s)
- Lucia Grassi
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Kyle L. Asfahl
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | | | - Ine Maenhout
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Andrea Sass
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Yannick Vande Weygaerde
- Cystic Fibrosis Reference Centre, Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
| | - Eva Van Braeckel
- Cystic Fibrosis Reference Centre, Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium
- Department of Internal Medicine and Paediatrics, Ghent University, Ghent, Belgium
| | - Bruno Verhasselt
- Laboratory of Medical Microbiology, Ghent University Hospital, Ghent, Belgium
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Jerina Boelens
- Laboratory of Medical Microbiology, Ghent University Hospital, Ghent, Belgium
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Michael M. Tunney
- School of Pharmacy, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Ajai A. Dandekar
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Aurélie Crabbé
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| |
Collapse
|
29
|
Amyx-Sherer K, Reichhardt C. Challenges and opportunities in elucidating the structures of biofilm exopolysaccharides: A case study of the Pseudomonas aeruginosa exopolysaccharide called Pel. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2024; 62:361-369. [PMID: 37919227 DOI: 10.1002/mrc.5405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 10/09/2023] [Accepted: 10/17/2023] [Indexed: 11/04/2023]
Abstract
Biofilm formation protects bacteria from antibiotic treatment and host immune responses, making biofilm infections difficult to treat. Within biofilms, bacterial cells are entangled in a self-produced extracellular matrix that typically includes exopolysaccharides. Molecular-level descriptions of biofilm matrix components, especially exopolysaccharides, have been challenging to attain due to their complex nature and lack of solubility and crystallinity. Solid-state nuclear magnetic resonance (NMR) has emerged as a key tool to determine the structure of biofilm matrix exopolysaccharides without degradative sample preparation. In this review, we discuss challenges of studying biofilm matrix exopolysaccharides and opportunities to develop solid-state NMR approaches to study these generally intractable materials. We specifically highlight investigations of the exopolysaccharide called Pel made by the opportunistic pathogen, Pseudomonas aeruginosa. We provide a roadmap for determining exopolysaccharide structure and discuss future opportunities to study such systems using solid-state NMR. The strategies discussed for elucidating biofilm exopolysaccharide structure should be broadly applicable to studying the structures of other glycans.
Collapse
Affiliation(s)
- Kristen Amyx-Sherer
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Courtney Reichhardt
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA
| |
Collapse
|
30
|
Rapsinski GJ, Michaels LA, Hill M, Yarrington KD, Haas AL, D’Amico EJ, Armbruster CR, Zemke A, Limoli D, Bomberger JM. Pseudomonas aeruginosa senses and responds to epithelial potassium flux via Kdp operon to promote biofilm. PLoS Pathog 2024; 20:e1011453. [PMID: 38820569 PMCID: PMC11168685 DOI: 10.1371/journal.ppat.1011453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/12/2024] [Accepted: 05/21/2024] [Indexed: 06/02/2024] Open
Abstract
Mucosa-associated biofilms are associated with many human disease states, but the host mechanisms promoting biofilm remain unclear. In chronic respiratory diseases like cystic fibrosis (CF), Pseudomonas aeruginosa establishes chronic infection through biofilm formation. P. aeruginosa can be attracted to interspecies biofilms through potassium currents emanating from the biofilms. We hypothesized that P. aeruginosa could, similarly, sense and respond to the potassium efflux from human airway epithelial cells (AECs) to promote biofilm. Using respiratory epithelial co-culture biofilm imaging assays of P. aeruginosa grown in association with CF bronchial epithelial cells (CFBE41o-), we found that P. aeruginosa biofilm was increased by potassium efflux from AECs, as examined by potentiating large conductance potassium channel, BKCa (NS19504) potassium efflux. This phenotype is driven by increased bacterial attachment and increased coalescence of bacteria into aggregates. Conversely, biofilm formation was reduced when AECs were treated with a BKCa blocker (paxilline). Using an agar-based macroscopic chemotaxis assay, we determined that P. aeruginosa chemotaxes toward potassium and screened transposon mutants to discover that disruption of the high-sensitivity potassium transporter, KdpFABC, and the two-component potassium sensing system, KdpDE, reduces P. aeruginosa potassium chemotaxis. In respiratory epithelial co-culture biofilm imaging assays, a KdpFABCDE deficient P. aeruginosa strain demonstrated reduced biofilm growth in association with AECs while maintaining biofilm formation on abiotic surfaces. Furthermore, we determined that the Kdp operon is expressed in vivo in people with CF and the genes are conserved in CF isolates. Collectively, these data suggest that P. aeruginosa biofilm formation can be increased by attracting bacteria to the mucosal surface and enhancing coalescence into microcolonies through aberrant AEC potassium efflux sensed by the KdpFABCDE system. These findings suggest host electrochemical signaling can enhance biofilm, a novel host-pathogen interaction, and potassium flux could be a therapeutic target to prevent chronic infections in diseases with mucosa-associated biofilms, like CF.
Collapse
Affiliation(s)
- Glenn J. Rapsinski
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United State of America
- Division of Infectious Disease, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Lia A. Michaels
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Madison Hill
- Department of Biology, Saint Vincent College, Latrobe, Pennsylvania, United States of America
| | - Kaitlin D. Yarrington
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Allison L. Haas
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United State of America
| | - Emily J. D’Amico
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United State of America
| | - Catherine R. Armbruster
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United State of America
| | - Anna Zemke
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Dominique Limoli
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Jennifer M. Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United State of America
| |
Collapse
|
31
|
Chance DL, Wang W, Waters JK, Mawhinney TP. Insights on Pseudomonas aeruginosa Carbohydrate Binding from Profiles of Cystic Fibrosis Isolates Using Multivalent Fluorescent Glycopolymers Bearing Pendant Monosaccharides. Microorganisms 2024; 12:801. [PMID: 38674745 PMCID: PMC11051836 DOI: 10.3390/microorganisms12040801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/07/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
Pseudomonas aeruginosa contributes to frequent, persistent, and, often, polymicrobial respiratory tract infections for individuals with cystic fibrosis (CF). Chronic CF infections lead to bronchiectasis and a shortened lifespan. P. aeruginosa expresses numerous adhesins, including lectins known to bind the epithelial cell and mucin glycoconjugates. Blocking carbohydrate-mediated host-pathogen and intra-biofilm interactions critical to the initiation and perpetuation of colonization offer promise as anti-infective treatment strategies. To inform anti-adhesion therapies, we profiled the monosaccharide binding of P. aeruginosa from CF and non-CF sources, and assessed whether specific bacterial phenotypic characteristics affected carbohydrate-binding patterns. Focusing at the cellular level, microscopic and spectrofluorometric tools permitted the solution-phase analysis of P. aeruginosa binding to a panel of fluorescent glycopolymers possessing distinct pendant monosaccharides. All P. aeruginosa demonstrated significant binding to glycopolymers specific for α-D-galactose, β-D-N-acetylgalactosamine, and β-D-galactose-3-sulfate. In each culture, a small subpopulation accounted for the binding. The carbohydrate anomeric configuration and sulfate ester presence markedly influenced binding. While this opportunistic pathogen from CF hosts presented with various colony morphologies and physiological activities, no phenotypic, physiological, or structural feature predicted enhanced or diminished monosaccharide binding. Important to anti-adhesive therapeutic strategies, these findings suggest that, regardless of phenotype or clinical source, P. aeruginosa maintain a small subpopulation that may readily associate with specific configurations of specific monosaccharides. This report provides insights into whole-cell P. aeruginosa carbohydrate-binding profiles and into the context within which successful anti-adhesive and/or anti-virulence anti-infective agents for CF must contend.
Collapse
Affiliation(s)
- Deborah L. Chance
- Department of Molecular Microbiology & Immunology, University of Missouri School of Medicine, Columbia, MO 65212, USA
- Department of Pediatrics, University of Missouri School of Medicine, Columbia, MO 65212, USA;
| | - Wei Wang
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA;
| | - James K. Waters
- Experiment Station Chemical Laboratories, University of Missouri, Columbia, MO 65211, USA;
| | - Thomas P. Mawhinney
- Department of Pediatrics, University of Missouri School of Medicine, Columbia, MO 65212, USA;
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA;
- Experiment Station Chemical Laboratories, University of Missouri, Columbia, MO 65211, USA;
| |
Collapse
|
32
|
Granton E, Brown L, Defaye M, Moazen P, Almblad H, Randall TE, Rich JD, Geppert A, Abdullah NS, Hassanabad MF, Hiroki CH, Farias R, Nguyen AP, Schubert C, Lou Y, Andonegui G, Iftinca M, Raju D, Vargas MA, Howell PL, Füzesi T, Bains J, Kurrasch D, Harrison JJ, Altier C, Yipp BG. Biofilm exopolysaccharides alter sensory-neuron-mediated sickness during lung infection. Cell 2024; 187:1874-1888.e14. [PMID: 38518773 DOI: 10.1016/j.cell.2024.03.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 01/04/2024] [Accepted: 03/01/2024] [Indexed: 03/24/2024]
Abstract
Infections of the lung cause observable sickness thought to be secondary to inflammation. Signs of sickness are crucial to alert others via behavioral-immune responses to limit contact with contagious individuals. Gram-negative bacteria produce exopolysaccharide (EPS) that provides microbial protection; however, the impact of EPS on sickness remains uncertain. Using genome-engineered Pseudomonas aeruginosa (P. aeruginosa) strains, we compared EPS-producers versus non-producers and a virulent Escherichia coli (E. coli) lung infection model in male and female mice. EPS-negative P. aeruginosa and virulent E. coli infection caused severe sickness, behavioral alterations, inflammation, and hypothermia mediated by TLR4 detection of the exposed lipopolysaccharide (LPS) in lung TRPV1+ sensory neurons. However, inflammation did not account for sickness. Stimulation of lung nociceptors induced acute stress responses in the paraventricular hypothalamic nuclei by activating corticotropin-releasing hormone neurons responsible for sickness behavior and hypothermia. Thus, EPS-producing biofilm pathogens evade initiating a lung-brain sensory neuronal response that results in sickness.
Collapse
Affiliation(s)
- Elise Granton
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Luke Brown
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Manon Defaye
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Inflammation Research Network, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Parisa Moazen
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Henrik Almblad
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Trevor E Randall
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Jacquelyn D Rich
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Andrew Geppert
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Nasser S Abdullah
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Inflammation Research Network, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Mortaza F Hassanabad
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Carlos H Hiroki
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Raquel Farias
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Angela P Nguyen
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Courtney Schubert
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Yuefei Lou
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Graciela Andonegui
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Mircea Iftinca
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Inflammation Research Network, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Deepa Raju
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Mario A Vargas
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - P Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Tamás Füzesi
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Cumming School of Medicine Optogenetics Core Facility, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jaideep Bains
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Krembil Research Institute, University Health Network, Toronto, ON, Canada.
| | - Deborah Kurrasch
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
| | - Joe Jonathan Harrison
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Biological Sciences, University of Calgary, Calgary, AB, Canada.
| | - Christophe Altier
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Inflammation Research Network, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
| | - Bryan G Yipp
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
| |
Collapse
|
33
|
Deiss-Yehiely E, Dzordzorme AE, Loiselle ME, Yonker LM, Hammond PT. Carboxylated Nanoparticle Surfaces Enhance Association with Mucoid Pseudomonas aeruginosa Biofilms. ACS APPLIED MATERIALS & INTERFACES 2024; 16:14573-14582. [PMID: 38484043 PMCID: PMC10982939 DOI: 10.1021/acsami.3c18656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/05/2024] [Accepted: 01/08/2024] [Indexed: 04/04/2024]
Abstract
Pseudomonas aeruginosa biofilms comprise three main polysaccharides: alginate, psl, and pel, which all imbue tolerance against exogenous antimicrobials. Nanoparticles (NPs) are an exciting new strategy to overcome the biofilm matrix for therapeutic delivery applications; however, zero existing FDA approvals for biofilm-specific NP formulations can be attributed to the complex interplay of physiochemical forces at the biofilm-NP interface. Here, we leverage a set of inducible, polysaccharide-specific, expressing isogenic P. aeruginosa mutants coupled with an assembled layer-by-layer NP (LbL NP) panel to characterize biofilm-NP interactions. When investigating these interactions using confocal microscopy, alginate-layered NPs associated more than dextran-sulfate-layered NPs with biofilms that had increased alginate production, including biofilms produced by mucoid P. aeruginosa isolates from people with cystic fibrosis. These differences were further confirmed in LbL NPs layered with polysaccharide- or hydrocarbon-based polymers with pendent carboxylate or sulfate functional groups. These data suggest carboxylated NP surfaces have enhanced interactions specifically with mucoid biofilms as compared to sulfated surfaces and lay the foundation for their inclusion as a design element for increasing biofilm-NP interactions and efficacious drug delivery.
Collapse
Affiliation(s)
- Elad Deiss-Yehiely
- Department
of Materials Science and Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
- Koch
Institute for Integrative Cancer Research, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| | - Abigail E. Dzordzorme
- Department
of Biological Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Maggie Elizabeth Loiselle
- Mucosal
Immunology and Biology Research Center, Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Department
of Pediatrics, Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
| | - Lael M. Yonker
- Mucosal
Immunology and Biology Research Center, Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Department
of Pediatrics, Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Harvard
Medical School, Boston, Massachusetts 02115, United States
| | - Paula T. Hammond
- Koch
Institute for Integrative Cancer Research, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
- Institute
for Soldier Nanotechnologies, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department
of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
34
|
Levy IK, Salustro D, Battaglini F, Lizarraga L, Murgida DH, Agusti R, D’Accorso N, Raventos Segura D, González Palmén L, Negri RM. Quantification of Enzymatic Biofilm Removal Using the Sauerbrey Equation: Application to the Case of Pseudomonas protegens. ACS OMEGA 2024; 9:10445-10458. [PMID: 38463305 PMCID: PMC10918834 DOI: 10.1021/acsomega.3c08475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 11/30/2023] [Accepted: 01/03/2024] [Indexed: 03/12/2024]
Abstract
A methodology for the quantitative analysis of enzymatic removal of biofilms (BF) was developed, based on a quartz crystal microbalance (QCM) under stationary conditions. This was applied to the case of Pseudomonas protegens (PP) BFs, through a series of five enzymes, whose removal activity was screened using the presented methodology. The procedure is based on the following: when BFs can be modeled as rigid materials, QCM can be used as a balance under stationary conditions for determining the BFs mass reduction by enzymatic removal. For considering a BF as a rigid model, energy dissipation effects, associated with viscoelastic properties of the BF, must be negligible. Hence, a QCM system with detection of dissipation (referred to as QCM with dissipation) was used for evaluating the energy losses, which, in fact, resulted in negligible energy losses in the case of dehydrated PP BFs, validating the application of the Sauerbrey equation for the change of mass calculations. The stationary methodology reduces operating times and simplifies data analysis in comparison to dynamic approaches based on flow setups, which requires the incorporation of dissipation effects due to the liquid media. By carrying out QCM, glycosidase-type enzymes showed BF removal higher than 80% at enzyme concentration 50 ppm, reaching removal over 90% in the cases of amylase and cellulase/xylanase enzymes. The highest removal percentage produced a reduction from about 15 to 1 μg in the BF mass. Amylase enzyme was tested from below 50 to 1 ppm, reaching around 60% of removal at 1 ppm. The obtained results were supported by other instrumental techniques such as Raman spectroscopy, attenuated total reflection Fourier transform infrared spectroscopy, atomic force microscopy, high performance anion exchange chromatography, thermogravimetric analysis, and differential scanning calorimetry. The removal quantifications obtained with QCM were compared with those obtained by well-established screening techniques (UV-vis spectrophotometry using crystal violet and agar diffusion test). The proposed methodology expands the possibility of using a quartz microbalance to perform enzymatic activity screening.
Collapse
Affiliation(s)
- Ivana K. Levy
- Instituto
de Química Física de los Materiales, Medio Ambiente
y Energía (INQUIMAE). Consejo Nacional de Investigaciones Científicas
y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Buenos Aires C1428EGA, Argentina
| | - Débora Salustro
- Instituto
de Química Física de los Materiales, Medio Ambiente
y Energía (INQUIMAE). Consejo Nacional de Investigaciones Científicas
y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Buenos Aires C1428EGA, Argentina
| | - Fernando Battaglini
- Instituto
de Química Física de los Materiales, Medio Ambiente
y Energía (INQUIMAE). Consejo Nacional de Investigaciones Científicas
y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Buenos Aires C1428EGA, Argentina
- Universidad
de Buenos Aires (UBA), Departamento de Química Inorgánica,
Analítica y Química Física. Facultad de Ciencias
Exactas y Naturales, Buenos Aires C1428EGA, Argentina
| | - Leonardo Lizarraga
- Universidad
de Buenos Aires (UBA), Departamento de Química Inorgánica,
Analítica y Química Física. Facultad de Ciencias
Exactas y Naturales, Buenos Aires C1428EGA, Argentina
- Centro
de Investigación en Bionanociencias (CIBION), Consejo Nacional
de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1425FQD, Argentina
| | - Daniel H. Murgida
- Instituto
de Química Física de los Materiales, Medio Ambiente
y Energía (INQUIMAE). Consejo Nacional de Investigaciones Científicas
y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Buenos Aires C1428EGA, Argentina
- Universidad
de Buenos Aires (UBA), Departamento de Química Inorgánica,
Analítica y Química Física. Facultad de Ciencias
Exactas y Naturales, Buenos Aires C1428EGA, Argentina
| | - Rosalía Agusti
- Centro
de Investigaciones en Hidratos de Carbono (CIHIDECAR), Consejo Nacional
de Investigaciones Científicas y Técnicas (CONICET),
Universidad de Buenos Aires, Buenos
Aires C1428EGA, Argentina
- Universidad
de Buenos Aires (UBA), Departamento de Química Orgánica,
Facultad de Ciencias Exactas y Naturales, Buenos Aires C1428EGA, Argentina
| | - Norma D’Accorso
- Centro
de Investigaciones en Hidratos de Carbono (CIHIDECAR), Consejo Nacional
de Investigaciones Científicas y Técnicas (CONICET),
Universidad de Buenos Aires, Buenos
Aires C1428EGA, Argentina
- Universidad
de Buenos Aires (UBA), Departamento de Química Orgánica,
Facultad de Ciencias Exactas y Naturales, Buenos Aires C1428EGA, Argentina
| | | | | | - R. Martín Negri
- Instituto
de Química Física de los Materiales, Medio Ambiente
y Energía (INQUIMAE). Consejo Nacional de Investigaciones Científicas
y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Buenos Aires C1428EGA, Argentina
- Universidad
de Buenos Aires (UBA), Departamento de Química Inorgánica,
Analítica y Química Física. Facultad de Ciencias
Exactas y Naturales, Buenos Aires C1428EGA, Argentina
| |
Collapse
|
35
|
Van Loon JC, Whitfield GB, Wong N, O'Neal L, Henrickson A, Demeler B, O'Toole GA, Parsek MR, Howell PL. Binding of GTP to BifA is required for the production of Pel-dependent biofilms in Pseudomonas aeruginosa. J Bacteriol 2024; 206:e0033123. [PMID: 38197635 PMCID: PMC10882990 DOI: 10.1128/jb.00331-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 12/13/2023] [Indexed: 01/11/2024] Open
Abstract
The Pel exopolysaccharide is one of the most mechanistically conserved and phylogenetically diverse bacterial biofilm matrix determinants. Pel is a major contributor to the structural integrity of Pseudomonas aeruginosa biofilms, and its biosynthesis is regulated by the binding of cyclic-3',5'-dimeric guanosine monophosphate (c-di-GMP) to the PelD receptor. c-di-GMP is synthesized from two molecules of guanosine triphosphate (GTP) by diguanylate cyclases with GGDEF domains and degraded by phosphodiesterases with EAL or HD-GYP domains. As the P. aeruginosa genome encodes 43 c-di-GMP metabolic enzymes, one way signaling specificity can be achieved is through direct interaction between specific enzyme-receptor pairs. Here, we show that the inner membrane hybrid GGDEF-EAL enzyme, BifA, directly interacts with PelD via its cytoplasmic HAMP, GGDEF, and EAL domains. Despite having no catalytic function, the degenerate active site motif of the BifA GGDEF domain (GGDQF) has retained the ability to bind GTP with micromolar affinity. Mutations that abolish GTP binding result in increased biofilm formation but stable global c-di-GMP levels. Our data suggest that BifA forms a dimer in solution and that GTP binding induces conformational changes in dimeric BifA that enhance the BifA-PelD interaction and stimulate its phosphodiesterase activity, thus reducing c-di-GMP levels and downregulating Pel biosynthesis. Structural comparisons between the dimeric AlphaFold2 model of BifA and the structures of other hybrid GGDEF-EAL proteins suggest that the regulation of BifA by GTP may occur through a novel mechanism.IMPORTANCEc-di-GMP is the most common cyclic dinucleotide used by bacteria to regulate phenotypes such as motility, biofilm formation, virulence factor production, cell cycle progression, and cell differentiation. While the identification and initial characterization of c-di-GMP metabolic enzymes are well established, our understanding of how these enzymes are regulated to provide signaling specificity remains understudied. Here we demonstrate that the inactive GGDEF domain of BifA binds GTP and regulates the adjacent phosphodiesterase EAL domain, ultimately downregulating Pel-dependent P. aeruginosa biofilm formation through an interaction with PelD. This discovery adds to the growing body of literature regarding how hybrid GGDEF-EAL enzymes are regulated and provides additional precedence for studying how direct interactions between c-di-GMP metabolic enzymes and effectors result in signaling specificity.
Collapse
Affiliation(s)
- Jaime C. Van Loon
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Gregory B. Whitfield
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Nicole Wong
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, Canada
| | - Lindsey O'Neal
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - Amy Henrickson
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Borries Demeler
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada
| | - G. A. O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Matthew R. Parsek
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - P. Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
36
|
Ruijgrok G, Wu DY, Overkleeft HS, Codée JDC. Synthesis and application of bacterial exopolysaccharides. Curr Opin Chem Biol 2024; 78:102418. [PMID: 38134611 DOI: 10.1016/j.cbpa.2023.102418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/02/2023] [Accepted: 12/03/2023] [Indexed: 12/24/2023]
Abstract
Exopolysaccharides are produced and excreted by bacteria in the generation of biofilms to provide a protective environment. These polysaccharides are generally generated as heterogeneous polymers of varying length, featuring diverse substitution patterns. To obtain well-defined fragments of these polysaccharides, organic synthesis often is the method of choice, as it allows for full control over chain length and the installation of a pre-determined substitution pattern. This review presents several recent syntheses of exopolysaccharide fragments of Pseudomonas aeruginosa and Staphylococcus aureus and illustrates how these have been used to study biosynthesis enzymes and generate synthetic glycoconjugate vaccines.
Collapse
Affiliation(s)
- Gijs Ruijgrok
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333, CC Leiden, the Netherlands
| | - Dung-Yeh Wu
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333, CC Leiden, the Netherlands
| | - Herman S Overkleeft
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333, CC Leiden, the Netherlands
| | - Jeroen D C Codée
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333, CC Leiden, the Netherlands.
| |
Collapse
|
37
|
Dai J, Luo W, Hu F, Li S. In vitro inhibition of Pseudomonas aeruginosa PAO1 biofilm formation by DZ2002 through regulation of extracellular DNA and alginate production. Front Cell Infect Microbiol 2024; 13:1333773. [PMID: 38268790 PMCID: PMC10806038 DOI: 10.3389/fcimb.2023.1333773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 12/15/2023] [Indexed: 01/26/2024] Open
Abstract
Introduction Pseudomonas aeruginosa (P. aeruginosa) is a common pathogen associated with biofilm infections, which can lead to persistent infections. Therefore, there is an urgent need to develop new anti-biofilm drugs. DZ2002 is a reversible inhibitor that targets S-adenosylhomocysteine hydrolase and possesses anti-inflammatory and immune-regulatory activities. However, its anti-biofilm activity has not been reported yet. Methods and results Therefore, we investigated the effect of DZ2002 on P. aeruginosa PAO1 biofilm formation by crystal violet staining (CV), real-time quantitative polymerase chain reaction (RT-qPCR) and confocal laser scanning microscopy (CLSM). The results indicated that although DZ2002 didn't affect the growth of planktonic PAO1, it could significantly inhibit the formation of mature biofilms. During the inhibition of biofilm formation by DZ2002, there was a parallel decrease in the synthesis of alginate and the expression level of alginate genes, along with a weakening of swarming motility. However, these results were unrelated to the expression of lasI, lasR, rhII, rhIR. Additionally, we also found that after treatment with DZ2002, the biofilms and extracellular DNA content of PAO1 were significantly reduced. Molecular docking results further confirmed that DZ2002 had a strong binding affinity with the active site of S-adenosylhomocysteine hydrolase (SahH) of PAO1. Discussion In summary, our results indicated that DZ2002 may interact with SahH in PAO1, inhibiting the formation of mature biofilms by downregulating alginate synthesis, extracellular DNA production and swarming motility. These findings demonstrate the potential value of DZ2002 in treating biofilm infections associated with P. aeruginosa.
Collapse
Affiliation(s)
- Jiaze Dai
- Medical Laboratory Center, Affiliated Hospital of Guangdong Medical University, Zhan Jiang, Guang Dong, China
| | - Wenying Luo
- Medical Laboratory Center, Affiliated Hospital of Guangdong Medical University, Zhan Jiang, Guang Dong, China
| | - Fei Hu
- Medical Laboratory Center, Affiliated Hospital of Guangdong Medical University, Zhan Jiang, Guang Dong, China
| | - Si Li
- General Medicine, Clinical Medicine, Kangda College of Nanjing Medical University, LianYun Gang, Jiang Su, China
| |
Collapse
|
38
|
Wells M, Mikesh M, Gordon V. Structure-preserving fixation allows scanning electron microscopy to reveal biofilm microstructure and interactions with immune cells. J Microsc 2024; 293:59-68. [PMID: 38098170 PMCID: PMC10764082 DOI: 10.1111/jmi.13252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/27/2023] [Accepted: 12/11/2023] [Indexed: 12/23/2023]
Abstract
Pseudomonas aeruginosa is a pathogen that forms robust biofilms which are commonly associated with chronic infections and cannot be successfully cleared by the immune system. Neutrophils, the most common white blood cells, target infections with pathogen-killing mechanisms that are rendered largely ineffective by the protective physicochemical structure of a biofilm. Visualisation of the complex interactions between immune cells and biofilms will advance understanding of how biofilms evade the immune system and could aid in developing treatment methods that promote immune clearance with minimal harm to the host. Scanning electron microscopy (SEM) distinguishes itself as a powerful, high-resolution tool for obtaining strikingly clear and detailed topographical images. However, taking full advantage of SEM's potential for high-resolution imaging requires that the fixation process simultaneously preserve both intricate biofilm architecture and the morphologies and structural signatures characterising neutrophils responses at an infection site. Standard aldehyde-based fixation techniques result in significant loss of biofilm matrix material and morphologies of responding immune cells, thereby obscuring the details of immune interactions with the biofilm matrix. Here we show an improved fixation technique using the cationic dye alcian blue to preserve and visualise neutrophil interactions with the three-dimensional architecture of P. aeruginosa biofilms. We also demonstrate that this technique better preserves structures of biofilms grown from two other bacterial species, Klebsiella pneumoniae and Burkholderia thailandensis.
Collapse
Affiliation(s)
- Marilyn Wells
- Department of Physics, The University of Texas at Austin, Austin, Texas, USA
- Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, Texas, USA
| | - Michelle Mikesh
- Center for Biomedical Research Support, The University of Texas at Austin, Austin, Texas, USA
| | - Vernita Gordon
- Department of Physics, The University of Texas at Austin, Austin, Texas, USA
- Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, Texas, USA
- Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Austin, Texas, USA
- LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, Texas, USA
| |
Collapse
|
39
|
Musuroi SI, Voinescu A, Musuroi C, Baditoiu LM, Muntean D, Izmendi O, Jumanca R, Licker M. The Challenges of The Diagnostic and Therapeutic Approach of Patients with Infectious Pathology in Emergency Medicine. J Pers Med 2023; 14:46. [PMID: 38248747 PMCID: PMC10821085 DOI: 10.3390/jpm14010046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/23/2023] [Accepted: 12/24/2023] [Indexed: 01/23/2024] Open
Abstract
The emergency department (ED) represents an important setting for addressing inappropriate antimicrobial prescribing practices because of the time constraints and the duration of microbiological diagnosis. The purpose of this study is to evaluate the etiology and antimicrobial resistance (AMR) pattern of the community-acquired pathogens, as well as the epidemiological characteristics of patients admitted through the ED, in order to guide appropriate antibiotic therapy. METHODS A retrospective observational study was performed on 657 patients, from whom clinical samples (urine, purulent secretions, blood cultures, etc.) were collected for microbiological diagnosis in the first 3 days after presentation in the ED. The identification of pathogens and the antimicrobial susceptibility testing with minimum inhibitory concentration determination were carried out according to the laboratory protocols. RESULTS From the 767 biological samples analyzed, 903 microbial isolates were identified. E. coli was most frequently isolated (24.25%), followed by Klebsiella spp., S. aureus (SA), and non-fermentative Gram-negative bacilli. E. coli strains maintained their natural susceptibility to most antibiotics tested. In the case of Pseudomonas spp. and Acinetobacter spp., increased rates of AMR were identified. Also, 32.3% of SA strains were community-acquired MRSA. CONCLUSIONS The introduction of rapid microbiological diagnostic methods in emergency medicine is imperative in order to timely identify AMR strains and improve therapeutic protocols.
Collapse
Affiliation(s)
- Silvia Ioana Musuroi
- Doctoral School, “Victor Babeș” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (S.I.M.)
- Internal Medicine Department, Municipal Emergency Clinical Hospital, 300254 Timisoara, Romania
| | - Adela Voinescu
- Doctoral School, “Victor Babeș” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (S.I.M.)
- Microbiology Department, Multidisciplinary Research Center of Antimicrobial Resistance, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (D.M.); (M.L.)
- Microbiology Laboratory, “Pius Brinzeu” County Clinical Emergency Hospital, 300723 Timisoara, Romania
| | - Corina Musuroi
- Microbiology Department, Multidisciplinary Research Center of Antimicrobial Resistance, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (D.M.); (M.L.)
- Microbiology Laboratory, “Pius Brinzeu” County Clinical Emergency Hospital, 300723 Timisoara, Romania
| | - Luminita Mirela Baditoiu
- Epidemiology Department, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania;
| | - Delia Muntean
- Microbiology Department, Multidisciplinary Research Center of Antimicrobial Resistance, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (D.M.); (M.L.)
- Microbiology Laboratory, “Pius Brinzeu” County Clinical Emergency Hospital, 300723 Timisoara, Romania
| | - Oana Izmendi
- Doctoral School, “Victor Babeș” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (S.I.M.)
- Microbiology Department, Multidisciplinary Research Center of Antimicrobial Resistance, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (D.M.); (M.L.)
- Microbiology Laboratory, “Pius Brinzeu” County Clinical Emergency Hospital, 300723 Timisoara, Romania
| | - Romanita Jumanca
- Romanian and Foreign Languages Department, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania;
| | - Monica Licker
- Microbiology Department, Multidisciplinary Research Center of Antimicrobial Resistance, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania; (D.M.); (M.L.)
- Microbiology Laboratory, “Pius Brinzeu” County Clinical Emergency Hospital, 300723 Timisoara, Romania
| |
Collapse
|
40
|
Jarzynka S, Makarewicz O, Weiss D, Minkiewicz-Zochniak A, Iwańska A, Skorupa W, Padzik M, Augustynowicz-Kopeć E, Olędzka G. The Impact of Pseudomonas aeruginosa Infection in Adult Cystic Fibrosis Patients-A Single Polish Centre Study. Pathogens 2023; 12:1440. [PMID: 38133323 PMCID: PMC10748198 DOI: 10.3390/pathogens12121440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/06/2023] [Accepted: 12/10/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND Pseudomonas aeruginosa (PA) is one of the most predominant pathogens of lung infections, often causing exacerbations in adult patients with cystic fibrosis (CF). MATERIALS AND METHODS Microbiological characterization of 74 PA isolates and to evaluate the correlations between the bacterial features and 44 adult Polish CF cohort clinical parameters. RESULTS The most common variant in the CF transmembrane conductance regulator (CFTR) gene was F508del (76.3%), followed by 3849+10kbC>T (26.3%). A total of 39.4% of the PA isolates showed multiple resistances. In patients with parameters pointing to a decline in lung function, there was a statistically significant moderate correlation with β-lactam resistance and a weak correlation between hospital frequency and colistin resistance. The mucoidity did not correlate with the biofilm formation ability, which showed 41.9% of the isolates. Proteolytic activity, observed in 60.8% of the clinical isolates, was weakly associated with motility detected in 78.4% of the strains. The genetic profiles of the PA were highly heterogeneous, and a weak positive correlation was established between cluster group and biofilm formation. CONCLUSION The findings suggest that there is a high variety in P. aeruginosa populations in adult CF patients. There is a need to monitor PA strains in groups of patients with cystic fibrosis, in particular, in terms of the occurrence of antibiotic resistance related to a decline in lung function.
Collapse
Affiliation(s)
- Sylwia Jarzynka
- Department of Medical Biology, Medical University of Warsaw, Litewska 14/16, 00-575 Warsaw, Poland; (A.M.-Z.); (M.P.); (G.O.)
| | - Oliwia Makarewicz
- Institute for Infectious Diseases and Infection Control, Jena University Hospital, 07747 Jena, Germany; (O.M.); (D.W.)
| | - Daniel Weiss
- Institute for Infectious Diseases and Infection Control, Jena University Hospital, 07747 Jena, Germany; (O.M.); (D.W.)
| | - Anna Minkiewicz-Zochniak
- Department of Medical Biology, Medical University of Warsaw, Litewska 14/16, 00-575 Warsaw, Poland; (A.M.-Z.); (M.P.); (G.O.)
| | - Agnieszka Iwańska
- Department of Microbiology, National Institute of Tuberculosis and Lung Diseases, Plocka 26, 01-138 Warsaw, Poland; (A.I.); (E.A.-K.)
| | - Wojciech Skorupa
- First Department of Lung Diseases, National Institute of Tuberculosis and Lung Diseases, Plocka 26, 01-138 Warsaw, Poland;
| | - Marcin Padzik
- Department of Medical Biology, Medical University of Warsaw, Litewska 14/16, 00-575 Warsaw, Poland; (A.M.-Z.); (M.P.); (G.O.)
| | - Ewa Augustynowicz-Kopeć
- Department of Microbiology, National Institute of Tuberculosis and Lung Diseases, Plocka 26, 01-138 Warsaw, Poland; (A.I.); (E.A.-K.)
| | - Gabriela Olędzka
- Department of Medical Biology, Medical University of Warsaw, Litewska 14/16, 00-575 Warsaw, Poland; (A.M.-Z.); (M.P.); (G.O.)
| |
Collapse
|
41
|
Wells MJ, Currie H, Gordon VD. Physiological Concentrations of Calcium Interact with Alginate and Extracellular DNA in the Matrices of Pseudomonas aeruginosa Biofilms to Impede Phagocytosis by Neutrophils. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:17050-17058. [PMID: 37972353 PMCID: PMC10764079 DOI: 10.1021/acs.langmuir.3c01637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Biofilms are communities of interacting microbes embedded in a matrix of polymer, protein, and other materials. Biofilms develop distinct mechanical characteristics that depend on their predominant matrix components. These matrix components may be produced by microbes themselves or, for infections in vivo, incorporated from the host environment. Pseudomonas aeruginosa (P. aeruginosa) is a human pathogen that forms robust biofilms that extensively tolerate antibiotics and effectively evade clearance by the immune system. Two of the important bacterial-produced polymers in the matrices of P. aeruginosa biofilms are alginate and extracellular DNA (eDNA), both of which are anionic and therefore have the potential to interact electrostatically with cations. Many physiological sites of infection contain significant concentrations of the calcium ion (Ca2+). In this study, we investigate the structural and mechanical impacts of Ca2+ supplementation in alginate-dominated biofilms grown in vitro, and we evaluate the impact of targeted enzyme treatments on clearance by immune cells. We use multiple-particle tracking microrheology to evaluate the changes in biofilm viscoelasticity caused by treatment with alginate lyase or DNase I. For biofilms grown without Ca2+, we correlate a decrease in relative elasticity with increased phagocytic success. However, we find that growth with Ca2+ supplementation disrupts this correlation except in the case where both enzymes are applied. This suggests that the calcium cation may be impacting the microstructure of the biofilm in nontrivial ways. Indeed, confocal laser scanning fluorescence microscopy and scanning electron microscopy reveal unique Ca2+-dependent eDNA and alginate microstructures. Our results suggest that the presence of Ca2+ drives the formation of structurally and compositionally discrete microdomains within the biofilm through electrostatic interactions with the anionic matrix components eDNA and alginate. Further, we observe that these structures serve a protective function as the dissolution of both components is required to render biofilm bacteria vulnerable to phagocytosis by neutrophils.
Collapse
Affiliation(s)
- Marilyn J. Wells
- Department of Physics, The University of Texas at Austin, 2515 Speedway, C1600, Austin, Texas 78712-1192, USA
- Center for Nonlinear Dynamics, The University of Texas at Austin, 2515 Speedway, Stop C1610, Austin, Texas 78712-11993, USA
| | - Hailey Currie
- Department of Physics, The University of Texas at Austin, 2515 Speedway, C1600, Austin, Texas 78712-1192, USA
- Center for Nonlinear Dynamics, The University of Texas at Austin, 2515 Speedway, Stop C1610, Austin, Texas 78712-11993, USA
| | - Vernita D. Gordon
- Department of Physics, The University of Texas at Austin, 2515 Speedway, C1600, Austin, Texas 78712-1192, USA
- Center for Nonlinear Dynamics, The University of Texas at Austin, 2515 Speedway, Stop C1610, Austin, Texas 78712-11993, USA
- Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Norman Hackerman Building, 100 East 24th St., NHB 4500, Austin, Texas 78712, USA
- LaMontagne Center for Infectious Disease, The University of Texas at Austin, Neural Molecular Science Building, 2506 Speedway, Stop A5000, Austin, Texas 78712, USA
| |
Collapse
|
42
|
Byeon CH, Kinney T, Saricayir H, Srinivasa S, Wells MK, Kim W, Akbey Ü. Tapping into the native Pseudomonas bacterial biofilm structure by high-resolution multidimensional solid-state NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 357:107587. [PMID: 37984030 PMCID: PMC10913148 DOI: 10.1016/j.jmr.2023.107587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 10/19/2023] [Accepted: 11/03/2023] [Indexed: 11/22/2023]
Abstract
We present a multidimensional magic-angle spinning (MAS) solid-state NMR (ssNMR) study to characterize native Pseudomonas fluorescens colony biofilms at natural abundance without isotope-labelling. By using a high-resolution INEPT-based 2D 1H-13C ssNMR spectrum and thorough peak deconvolution at the 1D ssNMR spectra, approximately 80/134 (in 1D/2D) distinct biofilm chemical sites were identified. We compared CP and INEPT 13C ssNMR spectra to differentiate signals originating from the mobile and rigid fractions of the biofilm, and qualitatively determined dynamical changes by comparing CP buildup behaviors. Protein and polysaccharide signals were differentiated and identified by utilizing FapC protein signals as a template, a biofilm forming functional amyloid from Pseudomonas. We identified several biofilm polysaccharide species such as glucose, mannan, galactose, heptose, rhamnan, fucose and N-acylated mannuronic acid by using 1H and 13C chemical shifts obtained from the 2D spectrum. To our knowledge, this study marks the first high-resolution multidimensional ssNMR characterization of a native bacterial biofilm. Our experimental pipeline can be readily applied to other in vitro biofilm model systems and natural biofilms and holds the promise of making a substantial impact on biofilm research, fostering new ideas and breakthroughs to aid in the development of strategic approaches to combat infections caused by biofilm-forming bacteria.
Collapse
Affiliation(s)
- Chang-Hyeock Byeon
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15261, United States
| | - Ted Kinney
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15261, United States
| | - Hakan Saricayir
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15261, United States
| | - Sadhana Srinivasa
- Department of Biological Sciences, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282, United States
| | - Meghan K Wells
- Department of Biological Sciences, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282, United States
| | - Wook Kim
- Department of Biological Sciences, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282, United States
| | - Ümit Akbey
- Department of Structural Biology, School of Medicine, University of Pittsburgh, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15261, United States.
| |
Collapse
|
43
|
Fernández-Billón M, Llambías-Cabot AE, Jordana-Lluch E, Oliver A, Macià MD. Mechanisms of antibiotic resistance in Pseudomonas aeruginosa biofilms. Biofilm 2023; 5:100129. [PMID: 37205903 PMCID: PMC10189392 DOI: 10.1016/j.bioflm.2023.100129] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 04/29/2023] [Accepted: 05/02/2023] [Indexed: 05/21/2023] Open
Abstract
Pseudomonas aeruginosa is a major cause of life-threatening acute infections and life-long lasting chronic infections. The characteristic biofilm mode of life in P. aeruginosa chronic infections severely limits the efficacy of antimicrobial therapies, as it leads to intrinsic tolerance, involving physical and physiological factors in addition to biofilm-specific genes that can confer a transient protection against antibiotics promoting the development of resistance. Indeed, a striking feature of this pathogen is the extraordinary capacity to develop resistance to nearly all available antibiotics through the selection of chromosomal mutations, evidenced by its outstanding and versatile mutational resistome. This threat is dramatically amplified in chronic infections, driven by the frequent emergence of mutator variants with enhanced spontaneous mutation rates. Thus, this mini review is focused on describing the complex interplay of antibiotic resistance mechanisms in P. aeruginosa biofilms, to provide potentially useful information for the design of effective therapeutic strategies.
Collapse
Affiliation(s)
- María Fernández-Billón
- Department of Microbiology, Hospital Universitario Son Espases, Health Research Institute of the Balearic Islands (IdISBa), 07120, Palma de Mallorca, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC), 28029, Madrid, Spain
| | - Aina E. Llambías-Cabot
- Department of Microbiology, Hospital Universitario Son Espases, Health Research Institute of the Balearic Islands (IdISBa), 07120, Palma de Mallorca, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC), 28029, Madrid, Spain
| | - Elena Jordana-Lluch
- Department of Microbiology, Hospital Universitario Son Espases, Health Research Institute of the Balearic Islands (IdISBa), 07120, Palma de Mallorca, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC), 28029, Madrid, Spain
| | - Antonio Oliver
- Department of Microbiology, Hospital Universitario Son Espases, Health Research Institute of the Balearic Islands (IdISBa), 07120, Palma de Mallorca, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC), 28029, Madrid, Spain
| | - María D. Macià
- Department of Microbiology, Hospital Universitario Son Espases, Health Research Institute of the Balearic Islands (IdISBa), 07120, Palma de Mallorca, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC), 28029, Madrid, Spain
- Corresponding author. Department of Microbiology, Hospital Universitario Son Espases, Crta. Vallemossa 79, 07120, Palma de Mallorca, Spain.
| |
Collapse
|
44
|
Kolodkin-Gal I, Parsek MR, Patrauchan MA. The roles of calcium signaling and calcium deposition in microbial multicellularity. Trends Microbiol 2023; 31:1225-1237. [PMID: 37429751 PMCID: PMC10772221 DOI: 10.1016/j.tim.2023.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/07/2023] [Accepted: 06/12/2023] [Indexed: 07/12/2023]
Abstract
Calcium signaling is an essential mediator of signal-controlling gene expression in most developmental systems. In addition, calcium has established extracellular functions as a structural component of biogenic minerals found in complex tissues. In bacteria, the formation of calcium carbonate structures is associated with complex colony morphology. Genes promoting the formation of biogenic minerals are essential for proper biofilm development and protection against antimicrobial solutes and toxins. Here we review recent findings on the role of calcium and calcium signaling as emerging regulators of biofilm formation in beneficial bacteria, as well as essential mediators of biofilm formation and virulence in human pathogens. The presented analysis concludes that the new understanding of calcium signaling may help to improve the performance of beneficial strains for sustainable agriculture, microbiome manipulation, and sustainable construction. Unraveling the roles of calcium may also promote the development of novel therapies against biofilm infections that target calcium uptake, calcium sensors, and calcium carbonate deposition.
Collapse
Affiliation(s)
- Ilana Kolodkin-Gal
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
| | - Matthew R Parsek
- Department of Microbiology, University of Washington, Seattle, WA, USA.
| | - Marianna A Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA.
| |
Collapse
|
45
|
Deal CE, Richards AF, Yeung T, Maron MJ, Wang Z, Lai YT, Fritz BR, Himansu S, Narayanan E, Liu D, Koleva R, Licht S, Hsiao CJ, Rajlic IL, Koch H, Kleyman M, Pulse ME, Weiss WJ, Doering JE, Lindberg SK, Mantis NJ, Carfi A, Plante OJ. An mRNA-based platform for the delivery of pathogen-specific IgA into mucosal secretions. Cell Rep Med 2023; 4:101253. [PMID: 37918405 PMCID: PMC10694625 DOI: 10.1016/j.xcrm.2023.101253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 07/28/2023] [Accepted: 09/29/2023] [Indexed: 11/04/2023]
Abstract
Colonization of the gut and airways by pathogenic bacteria can lead to local tissue destruction and life-threatening systemic infections, especially in immunologically compromised individuals. Here, we describe an mRNA-based platform enabling delivery of pathogen-specific immunoglobulin A (IgA) monoclonal antibodies into mucosal secretions. The platform consists of synthetic mRNA encoding IgA heavy, light, and joining (J) chains, packaged in lipid nanoparticles (LNPs) that express glycosylated, dimeric IgA with functional activity in vitro and in vivo. Importantly, mRNA-derived IgA had a significantly greater serum half-life and a more native glycosylation profile in mice than did a recombinantly produced IgA. Expression of an mRNA encoded Salmonella-specific IgA in mice resulted in intestinal localization and limited Peyer's patch invasion. The same mRNA-LNP technology was used to express a Pseudomonas-specific IgA that protected from a lung challenge. Leveraging the mRNA antibody technology as a means to intercept bacterial pathogens at mucosal surfaces opens up avenues for prophylactic and therapeutic interventions.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Ding Liu
- Moderna, Inc., Cambridge, MA 02139, USA
| | | | | | | | | | | | | | - Mark E Pulse
- HSC College of Pharmacy, University of North Texas, Fort Worth, TX 76132, USA
| | - William J Weiss
- HSC College of Pharmacy, University of North Texas, Fort Worth, TX 76132, USA
| | - Jennifer E Doering
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12211, USA
| | - Samantha K Lindberg
- Department of Biomedical Sciences, University at Albany School of Public Health, Rensselaer, NY 12144, USA
| | - Nicholas J Mantis
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12211, USA; Department of Biomedical Sciences, University at Albany School of Public Health, Rensselaer, NY 12144, USA
| | | | | |
Collapse
|
46
|
Nazeer RR, Wang M, Welch M. More than just a gel: the extracellular matrixome of Pseudomonas aeruginosa. Front Mol Biosci 2023; 10:1307857. [PMID: 38028553 PMCID: PMC10679415 DOI: 10.3389/fmolb.2023.1307857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 10/31/2023] [Indexed: 12/01/2023] Open
Abstract
Armed with an arsenal of protein secretion systems, antibiotic efflux pumps, and the occasional proclivity for explosive self-destruction, Pseudomonas aeruginosa has become a model for the study of bacterial pathogenesis and biofilm formation. There is accruing evidence to suggest that the biofilm matrix-the bioglue that holds the structure together-acts not only in a structural capacity, but is also a molecular "net" whose function is to capture and retain certain secreted products (including proteins and small molecules). In this perspective, we argue that the biofilm matrixome is a distinct extracellular compartment, and one that is differentiated from the bulk secretome. Some of the points we raise are deliberately speculative, but are becoming increasingly accessible to experimental investigation.
Collapse
Affiliation(s)
| | | | - Martin Welch
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
47
|
Gheorghita AA, Wozniak DJ, Parsek MR, Howell PL. Pseudomonas aeruginosa biofilm exopolysaccharides: assembly, function, and degradation. FEMS Microbiol Rev 2023; 47:fuad060. [PMID: 37884397 PMCID: PMC10644985 DOI: 10.1093/femsre/fuad060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 10/04/2023] [Accepted: 10/25/2023] [Indexed: 10/28/2023] Open
Abstract
The biofilm matrix is a fortress; sheltering bacteria in a protective and nourishing barrier that allows for growth and adaptation to various surroundings. A variety of different components are found within the matrix including water, lipids, proteins, extracellular DNA, RNA, membrane vesicles, phages, and exopolysaccharides. As part of its biofilm matrix, Pseudomonas aeruginosa is genetically capable of producing three chemically distinct exopolysaccharides - alginate, Pel, and Psl - each of which has a distinct role in biofilm formation and immune evasion during infection. The polymers are produced by highly conserved mechanisms of secretion, involving many proteins that span both the inner and outer bacterial membranes. Experimentally determined structures, predictive modelling of proteins whose structures are yet to be solved, and structural homology comparisons give us insight into the molecular mechanisms of these secretion systems, from polymer synthesis to modification and export. Here, we review recent advances that enhance our understanding of P. aeruginosa multiprotein exopolysaccharide biosynthetic complexes, and how the glycoside hydrolases/lyases within these systems have been commandeered for antimicrobial applications.
Collapse
Affiliation(s)
- Andreea A Gheorghita
- Program in Molecular Medicine, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Medical Science Building, 1 King's College Cir, Toronto, ON M5S 1A8, Canada
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, The Ohio State University College of Medicine, 776 Biomedical Research Tower, 460 W 12th Ave, Columbus, OH 43210, United States
- Department of Microbiology, The Ohio State University College, Biological Sciences Bldg, 105, 484 W 12th Ave, Columbus, OH 43210, United States
| | - Matthew R Parsek
- Department of Microbiology, University of Washington, Health Sciences Bldg, 1705 NE Pacific St, Seattle, WA 98195-7735, United States
| | - P Lynne Howell
- Program in Molecular Medicine, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Medical Science Building, 1 King's College Cir, Toronto, ON M5S 1A8, Canada
| |
Collapse
|
48
|
Zemke AC, D'Amico EJ, Torres AM, Carreno-Florez GP, Keeley P, DuPont M, Kasturiarachi N, Bomberger JM. Bacterial respiratory inhibition triggers dispersal of Pseudomonas aeruginosa biofilms. Appl Environ Microbiol 2023; 89:e0110123. [PMID: 37728340 PMCID: PMC10617509 DOI: 10.1128/aem.01101-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 07/14/2023] [Indexed: 09/21/2023] Open
Abstract
Pseudomonas aeruginosa grows as a biofilm under many environmental conditions, and the bacterium can disperse from biofilms via highly regulated, dynamic processes. However, physiologic triggers of biofilm dispersal remain poorly understood. Based on prior literature describing dispersal triggered by forms of starvation, we tested bacterial respiratory inhibitors for biofilm dispersal in two models resembling chronic airway infections. Our underlying hypothesis was that respiratory inhibitors could serve as a model for the downstream effects of starvation. We used two experimental conditions. In the first condition, biofilms were grown and dispersed from the surface of airway epithelial cells, and the second condition was a model where biofilms were grown on glass in cell culture media supplemented with host-relevant iron sources. In both biofilm models, the respiratory inhibitors potassium cyanide and sodium azide each triggered biofilm dispersal. We hypothesized that cyanide-induced dispersal was due to respiratory inhibition rather than signaling via an alternative mechanism, and, indeed, if respiration was supported by overexpression of cyanide-insensitive oxidase, dispersal was prevented. Dispersal required the activity of the cyclic-di-GMP regulated protease LapG, reinforcing the role of matrix degradation in dispersal. Finally, we examined the roles of individual phosphodiesterases, previously implicated in dispersal to specific triggers, and found signaling to be highly redundant. Combined deletion of the phosphodiesterases dipA, bifA, and rbdA was required to attenuate the dispersal phenotype. In summary, this work adds insight into the physiology of biofilm dispersal under environmental conditions in which bacterial respiration is abruptly limited. IMPORTANCE The bacterium Pseudomonas aeruginosa grows in biofilm communities that are very difficult to treat in human infections. Growing as a biofilm can protect bacteria from antibiotics and the immune system. Bacteria can leave a biofilm through a process called "dispersal." Dispersed bacteria seed new growth areas and are more susceptible to killing by antibiotics. The triggers for biofilm dispersal are not well understood, and if we understood dispersal better it might lead to the development of new treatments for infection. In this paper, we find that inhibiting P. aeurginosa's ability to respire (generate energy) can trigger dispersal from a biofilm grown in association with human respiratory epithelial cells in culture. The dispersal process requires a protease which is previously known to degrade the biofilm matrix. These findings give us a better understanding of how the biofilm dispersal process works so that future research can discover better ways of clearing bacteria growing in biofilms.
Collapse
Affiliation(s)
- Anna C. Zemke
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Emily J. D'Amico
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Angela M. Torres
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Grace P. Carreno-Florez
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Patrick Keeley
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Matt DuPont
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Naomi Kasturiarachi
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jennifer M. Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
49
|
Bonincontro G, Scuderi SA, Marino A, Simonetti G. Synergistic Effect of Plant Compounds in Combination with Conventional Antimicrobials against Biofilm of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida spp. Pharmaceuticals (Basel) 2023; 16:1531. [PMID: 38004397 PMCID: PMC10675371 DOI: 10.3390/ph16111531] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/20/2023] [Accepted: 10/26/2023] [Indexed: 11/26/2023] Open
Abstract
Bacterial and fungal biofilm has increased antibiotic resistance and plays an essential role in many persistent diseases. Biofilm-associated chronic infections are difficult to treat and reduce the efficacy of medical devices. This global problem has prompted extensive research to find alternative strategies to fight microbial chronic infections. Plant bioactive metabolites with antibiofilm activity are known to be potential resources to alleviate this problem. The phytochemical screening of some medicinal plants showed different active groups, such as stilbenes, tannins, alkaloids, terpenes, polyphenolics, flavonoids, lignans, quinones, and coumarins. Synergistic effects can be observed in the interaction between plant compounds and conventional drugs. This review analyses and summarises the current knowledge on the synergistic effects of plant metabolites in combination with conventional antimicrobials against biofilms of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The synergism of conventional antimicrobials with plant compounds can modify and inhibit the mechanisms of acquired resistance, reduce undesirable effects, and obtain an appropriate therapeutic effect at lower doses. A deeper knowledge of these combinations and of their possible antibiofilm targets is needed to develop next-generation novel antimicrobials and/or improve current antimicrobials to fight drug-resistant infections attributed to biofilm.
Collapse
Affiliation(s)
- Graziana Bonincontro
- Department of Environmental Biology, Sapienza University of Rome, P.le Aldo Moro, 5, 00185 Roma, Italy;
| | - Sarah Adriana Scuderi
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D’Alcontres, 98100 Messina, Italy;
| | - Andreana Marino
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno D’Alcontres, 98100 Messina, Italy;
| | - Giovanna Simonetti
- Department of Environmental Biology, Sapienza University of Rome, P.le Aldo Moro, 5, 00185 Roma, Italy;
| |
Collapse
|
50
|
Wells MJ, Currie H, Gordon VD. Physiological concentrations of calcium interact with alginate and extracellular DNA in the matrices of Pseudomonas aeruginosa biofilms to impede phagocytosis by neutrophils. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.23.563605. [PMID: 37961083 PMCID: PMC10634743 DOI: 10.1101/2023.10.23.563605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Biofilms are communities of interacting microbes embedded in a matrix of polymer, protein, and other materials. Biofilms develop distinct mechanical characteristics that depend on their predominant matrix components. These matrix components may be produced by microbes themselves or, for infections in vivo, incorporated from the host environment. Pseudomonas aeruginosa is a human pathogen that forms robust biofilms that extensively tolerate antibiotics and effectively evade clearance by the immune system. Two of the important bacterial-produced polymers in the matrices of P. aeruginosa biofilms are alginate and extracellular DNA (eDNA), both of which are anionic and therefore have the potential to interact electrostatically with cations. Many physiological sites of infection contain significant concentrations of the calcium ion (Ca2+). In this study we investigate the structural and mechanical impacts of Ca2+ supplementation in alginate-dominated biofilms grown in vitro and we evaluate the impact of targeted enzyme treatments on clearance by immune cells. We use multiple particle tracking microrheology to evaluate the changes in biofilm viscoelasticity caused by treatment with alginate lyase and/or DNAse I. For biofilms grown without Ca2+, we correlate a decrease in relative elasticity with increased phagocytic success. However, we find that growth with Ca2+ supplementation disrupts this correlation except in the case where both enzymes are applied. This suggests that the calcium cation may be impacting the microstructure of the biofilm in non-trivial ways. Indeed, confocal laser scanning fluorescence microscopy and scanning electron microscopy reveal unique Ca2+-dependent eDNA and alginate microstructures. Our results suggest that the presence of Ca2+ drives the formation of structurally and compositionally discrete microdomains within the biofilm through electrostatic interactions with the anionic matrix components eDNA and alginate. Further, we observe that these structures serve a protective function as the dissolution of both components is required to render biofilm bacteria vulnerable to phagocytosis by neutrophils.
Collapse
Affiliation(s)
- Marilyn J. Wells
- Department of Physics, The University of Texas at Austin, 2515 Speedway, C1600, Austin, Texas 78712-1192, USA
- Center for Nonlinear Dynamics, The University of Texas at Austin, 2515 Speedway, Stop C1610, Austin, Texas 78712-11993, USA
| | - Hailey Currie
- Department of Physics, The University of Texas at Austin, 2515 Speedway, C1600, Austin, Texas 78712-1192, USA
- Center for Nonlinear Dynamics, The University of Texas at Austin, 2515 Speedway, Stop C1610, Austin, Texas 78712-11993, USA
| | - Vernita D. Gordon
- Department of Physics, The University of Texas at Austin, 2515 Speedway, C1600, Austin, Texas 78712-1192, USA
- Center for Nonlinear Dynamics, The University of Texas at Austin, 2515 Speedway, Stop C1610, Austin, Texas 78712-11993, USA
- Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Norman Hackerman Building, 100 East 24th St., NHB 4500, Austin, Texas 78712, USA
- LaMontagne Center for Infectious Disease, The University of Texas at Austin, Neural Molecular Science Building, 2506 Speedway, Stop A5000, Austin, Texas 78712, USA
| |
Collapse
|