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Weaver AA, Jia J, Cutri AR, Madukoma CS, Vaerewyck CM, Bohn PW, Shrout JD. Alkyl quinolones mediate heterogeneous colony biofilm architecture that improves community-level survival. J Bacteriol 2024; 206:e0009524. [PMID: 38564677 PMCID: PMC11025328 DOI: 10.1128/jb.00095-24] [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: 03/05/2024] [Accepted: 03/11/2024] [Indexed: 04/04/2024] Open
Abstract
Bacterial communities exhibit complex self-organization that contributes to their survival. To better understand the molecules that contribute to transforming a small number of cells into a heterogeneous surface biofilm community, we studied acellular aggregates, structures seen by light microscopy in Pseudomonas aeruginosa colony biofilms using light microscopy and chemical imaging. These structures differ from cellular aggregates, cohesive clusters of cells important for biofilm formation, in that they are visually distinct from cells using light microscopy and are reliant on metabolites for assembly. To investigate how these structures benefit a biofilm community we characterized three recurrent types of acellular aggregates with distinct geometries that were each abundant in specific areas of these biofilms. Alkyl quinolones (AQs) were essential for the formation of all aggregate types with AQ signatures outside the aggregates below the limit of detection. These acellular aggregates spatially sequester AQs and differentiate the biofilm space. However, the three types of aggregates showed differing properties in their size, associated cell death, and lipid content. The largest aggregate type co-localized with spatially confined cell death that was not mediated by Pf4 bacteriophage. Biofilms lacking AQs were absent of localized cell death but exhibited increased, homogeneously distributed cell death. Thus, these AQ-rich aggregates regulate metabolite accessibility, differentiate regions of the biofilm, and promote survival in biofilms.IMPORTANCEPseudomonas aeruginosa is an opportunistic pathogen with the ability to cause infection in the immune-compromised. It is well established that P. aeruginosa biofilms exhibit resilience that includes decreased susceptibility to antimicrobial treatment. This work examines the self-assembled heterogeneity in biofilm communities studying acellular aggregates, regions of condensed matter requiring alkyl quinolones (AQs). AQs are important to both virulence and biofilm formation. Aggregate structures described here spatially regulate the accessibility of these AQs, differentiate regions of the biofilm community, and despite their association with autolysis, correlate with improved P. aeruginosa colony biofilm survival.
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Affiliation(s)
- Abigail A. Weaver
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Jin Jia
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Allison R. Cutri
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
| | - Chinedu S. Madukoma
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Catherine M. Vaerewyck
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Paul W. Bohn
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, USA
| | - Joshua D. Shrout
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana, USA
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
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Kameswaran S, Gujjala S, Zhang S, Kondeti S, Mahalingam S, Bangeppagari M, Bellemkonda R. Quenching and quorum sensing in bacterial bio-films. Res Microbiol 2024; 175:104085. [PMID: 37268165 DOI: 10.1016/j.resmic.2023.104085] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 06/04/2023]
Abstract
Quorum sensing (QS) is the ability of bacteria to monitor their population density and adjust gene expression accordingly. QS-regulated processes include host-microbe interactions, horizontal gene transfer, and multicellular behaviours (such as the growth and development of biofilm). The creation, transfer, and perception of bacterial chemicals known as autoinducers or QS signals are necessary for QS signalling (e.g. N-acylhomoserine lactones). Quorum quenching (QQ), another name for the disruption of QS signalling, comprises a wide range of events and mechanisms that are described and analysed in this study. In order to better comprehend the targets of the QQ phenomena that organisms have naturally developed and are currently being actively researched from practical perspectives, we first surveyed the diversity of QS-signals and QS-associated responses. Next, the mechanisms, molecular players, and targets related to QS interference are discussed, with a focus on natural QQ enzymes and compounds that function as QS inhibitors. To illustrate the processes and biological functions of QS inhibition in microbe-microbe and host-microbe interactions, a few QQ paradigms are described in detail. Finally, certain QQ techniques are offered as potential instruments in a variety of industries, including agriculture, medical, aquaculture, crop production, and anti-biofouling areas.
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Affiliation(s)
- Srinivasan Kameswaran
- Department of Botany, Vikrama Simhapuri University College, Kavali, Andhra Pradesh, India
| | - Sudhakara Gujjala
- Department of Biochemistry, Sri Krishnadevaray a University, Ananthapuram, Andhra Pradesh, India
| | - Shaoqing Zhang
- School of Chemistry and Civil Engineering, Shaoguan University, Shaoguan, 512005, PR China
| | - Suresh Kondeti
- Multi-Disciplinary Research Unit, Nizam's Institute of Medical Sciences, Hyderabad, 500082, India
| | - Sundararajan Mahalingam
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Manjunatha Bangeppagari
- Department of Cell Biology & Molecular Genetics, Sri Devaraj Urs Academy of Higher Education and Research (Deemed to Be University), Tamaka, Kolar, 563103, Karnataka, India
| | - Ramesh Bellemkonda
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA.
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Díaz-Navarro M, Samaniego R, Piqueras JC, Díez R, Hafian R, Manzano I, Muñoz P, Guembe M. Understanding the diagnosis of catheter-related bloodstream infection: real-time monitoring of biofilm growth dynamics using time-lapse optical microscopy. Front Cell Infect Microbiol 2023; 13:1286527. [PMID: 38125909 PMCID: PMC10731284 DOI: 10.3389/fcimb.2023.1286527] [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: 08/31/2023] [Accepted: 11/13/2023] [Indexed: 12/23/2023] Open
Abstract
Background The differential time to positivity (DTTP) technique is recommended for the conservative diagnosis of catheter-related bloodstream infection (C-RBSI). The technique is based on a 120-minute difference between microbial growth in blood drawn through the catheter and blood drawn through a peripheral vein. However, this cut-off has failed to confirm C-RBSI caused by Candida spp. and Staphylococcus aureus. Objective We hypothesized that the biofilm of both microorganisms disperses faster than that of other microorganisms and that microbial load is rapidly equalized between catheter and peripheral blood. Therefore, our aim was to compare the biofilm dynamics of various microorganisms. Methods Biofilm of ATCC strains of methicillin-resistant Staphylococcus epidermidis, methicillin-susceptible S. aureus, Enterococcus faecalis, Escherichia coli and Candida albicans was grown on silicon disks and analyzed using time-lapse optical microscopy. The time-lapse images of biofilms were processed using ImageJ2 software. Cell dispersal time and biofilm thickness were calculated. Results The mean (standard deviation) dispersal time in C. albicans and S. aureus biofilms was at least nearly 3 hours lower than in biofilm of S. epidermidis, and at least 15 minutes than in E. faecalis and E. coli biofilms. Conclusion Our findings could explain why early dissemination of cells in C. albicans and S. aureus prevents us from confirming or ruling out the catheter as the source of the bloodstream infection using the cut-off of 120 minutes in the DTTP technique. In addition, DTTP may not be sufficiently reliable for E. coli since their dispersion time is less than the cut-off of 120 minutes.
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Affiliation(s)
- Marta Díaz-Navarro
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Rafael Samaniego
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
- Confocal Microscopy Unit, Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | | | - Rafael Díez
- School of Biology, Universidad Complutense de Madrid, Madrid, Spain
| | - Rama Hafian
- School of Biology, Universidad Complutense de Madrid, Madrid, Spain
| | - Irene Manzano
- School of Biology, Universidad Complutense de Madrid, Madrid, Spain
| | - Patricia Muñoz
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
- CIBER Enfermedades Respiratorias-CIBERES (CB06/06/0058), Madrid, Spain
- School of Medicine, Universidad Complutense de Madrid, Madrid, Spain
| | - María Guembe
- Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
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Pellerito C, Presentato A, Lazzara G, Cavallaro G, Alduina R, Fiore T. New Biocide Based on Tributyltin(IV) Ferulate-Loaded Halloysite Nanotubes for Preserving Historical Paper Artworks. Molecules 2023; 28:7953. [PMID: 38138442 PMCID: PMC10745945 DOI: 10.3390/molecules28247953] [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: 10/17/2023] [Revised: 11/30/2023] [Accepted: 12/01/2023] [Indexed: 12/24/2023] Open
Abstract
Combining biologically active compounds with nanocarriers is an emerging and promising strategy for enhancing the activities of molecules while reducing their levels of toxicity. Green nanomaterials have recently gained momentum in developing protocols for treating and preserving artifacts. In this study, we designed a functional biohybrid material by incorporating tributyltin(IV) ferulate (TBT-F) into halloysite nanotubes (HNTs), generating a new formulation called HNT/TBT-F. The primary objective was to develop a formulation with robust antimicrobial properties and reinforcing features for treating paper with artistic and historical value. To characterize HNT/TBT-F, assess the HNT's loading capacity, and investigate the TBT-F release kinetics from the nanotubes, various analytical techniques, including UV-Vis and infrared spectroscopies, thermogravimetry, and microscopy analysis, were employed. Furthermore, we evaluated the antimicrobial potential of TBT-F and HNT/TBT-F against Kocuria rhizophila, a bacterial strain known for its opportunistic behavior and a cause of artifact biodeterioration. HNT/TBT-F exhibited a significantly stronger bactericidal effect than TBT-F alone against K. rhizophila cells growing planktonically or those forming a biofilm. This enhanced performance could relate to the confinement of TBT-F within the nanotubes, which likely improved its physical-chemical stability and increased the local concentration of TBT-F upon contact with the bacterial cells. Additionally, we evaluated the mechanical properties of a paper treated with HNT/TBT-F, assessing any potential alterations in its color. The findings of this study highlight the favorable attributes of the HNT/TBT-F formulation and its potential for developing protocols aimed at consolidating and preserving culturally significant paper objects.
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Affiliation(s)
- Claudia Pellerito
- Dipartimento di Fisica Chimica-Emilio Segrè (DiFC), Università degli Studi di Palermo, Viale delle Scienze, Ed. 17, 90128 Palermo, Italy; (C.P.); (G.L.); (G.C.)
| | - Alessandro Presentato
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Viale delle Scienze, Ed. 16, 90128 Palermo, Italy; (A.P.); (R.A.)
| | - Giuseppe Lazzara
- Dipartimento di Fisica Chimica-Emilio Segrè (DiFC), Università degli Studi di Palermo, Viale delle Scienze, Ed. 17, 90128 Palermo, Italy; (C.P.); (G.L.); (G.C.)
| | - Giuseppe Cavallaro
- Dipartimento di Fisica Chimica-Emilio Segrè (DiFC), Università degli Studi di Palermo, Viale delle Scienze, Ed. 17, 90128 Palermo, Italy; (C.P.); (G.L.); (G.C.)
| | - Rosa Alduina
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Viale delle Scienze, Ed. 16, 90128 Palermo, Italy; (A.P.); (R.A.)
| | - Tiziana Fiore
- Dipartimento di Fisica Chimica-Emilio Segrè (DiFC), Università degli Studi di Palermo, Viale delle Scienze, Ed. 17, 90128 Palermo, Italy; (C.P.); (G.L.); (G.C.)
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Guo Y, Mao Z, Ran F, Sun J, Zhang J, Chai G, Wang J. Nanotechnology-Based Drug Delivery Systems to Control Bacterial-Biofilm-Associated Lung Infections. Pharmaceutics 2023; 15:2582. [PMID: 38004561 PMCID: PMC10674810 DOI: 10.3390/pharmaceutics15112582] [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: 08/31/2023] [Revised: 10/09/2023] [Accepted: 10/17/2023] [Indexed: 11/26/2023] Open
Abstract
Airway mucus dysfunction and impaired immunological defenses are hallmarks of several lung diseases, including asthma, cystic fibrosis, and chronic obstructive pulmonary diseases, and are mostly causative factors in bacterial-biofilm-associated respiratory tract infections. Bacteria residing within the biofilm architecture pose a complex challenge in clinical settings due to their increased tolerance to currently available antibiotics and host immune responses, resulting in chronic infections with high recalcitrance and high rates of morbidity and mortality. To address these unmet clinical needs, potential anti-biofilm therapeutic strategies are being developed to effectively control bacterial biofilm. This review focuses on recent advances in the development and application of nanoparticulate drug delivery systems for the treatment of biofilm-associated respiratory tract infections, especially addressing the respiratory barriers of concern for biofilm accessibility and the various types of nanoparticles used to combat biofilms. Understanding the obstacles facing pulmonary drug delivery to bacterial biofilms and nanoparticle-based approaches to combatting biofilm may encourage researchers to explore promising treatment modalities for bacterial-biofilm-associated chronic lung infections.
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Affiliation(s)
- Yutong Guo
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Zeyuan Mao
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Fang Ran
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jihong Sun
- Department of Radiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Jingfeng Zhang
- The Key Laboratory of Diagnosis and Treatment of Digestive System Tumors of Zhejiang Province, Ningbo 315000, China
| | - Guihong Chai
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jian Wang
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510180, China
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Leighton RE, Xiong L, Anderson GK, Astarita GM, Cai G, Norman RS, Decho AW. Vibrio parahaemolyticus and Vibrio vulnificus in vitro biofilm dispersal from microplastics influenced by simulated human environment. Front Microbiol 2023; 14:1236471. [PMID: 37854331 PMCID: PMC10579612 DOI: 10.3389/fmicb.2023.1236471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 09/12/2023] [Indexed: 10/20/2023] Open
Abstract
Growing concerns exist regarding human ingestion of contaminated seafood that contains Vibrio biofilms on microplastics (MPs). One of the mechanisms enhancing biofilm related infections in humans is due to biofilm dispersion, a process that triggers release of bacteria from biofilms into the surrounding environment, such as the gastrointestinal tract of human hosts. Dispersal of cells from biofilms can occur in response to environmental conditions such as sudden changes in temperature, pH and nutrient conditions, as the bacteria leave the biofilm to find a more stable environment to colonize. This study evaluated how brief exposures to nutrient starvation, elevated temperature, different pH levels and simulated human media affect Vibrio parahaemolyticus and Vibrio vulnificus biofilm dispersal and processes on and from low-density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS) MPs. Both species were able to adequately disperse from all types of plastics under most exposure conditions. V. parahaemolyticus was able to tolerate and survive the low pH that resembles the gastric environment compared to V. vulnificus. pH had a significantly (p ≤ 0.05) positive effect on overall V. parahaemolyticus biofilm biomass in microplates and cell colonization from PP and PS. pH also had a positive effect on V. vulnificus cell colonization from LDPE and PP. However, most biofilm biomass, biofilm cell and dispersal cell densities of both species greatly varied after exposure to elevated temperature, pH, and nutrient starvation. It was also found that certain exposures to simulated human media affected both V. parahaemolyticus and V. vulnificus biofilm biomass and biofilm cell densities on LDPE, PP and PS compared to exposure to traditional media of similar pH. Cyclic-di-GMP was higher in biofilm cells compared to dispersal cells, but exposure to more stressful conditions significantly increased signal concentrations in both biofilm and dispersal states. Taken together, this study suggests that human pathogenic strains of V. parahaemolyticus and V. vulnificus can rapidly disperse with high cell densities from different plastic types in vitro. However, the biofilm dispersal process is highly variable, species specific and dependent on plastic type, especially under different human body related environmental exposures.
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Affiliation(s)
- Ryan E. Leighton
- Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, United States
- Department of Environmental Health Sciences, NIEHS Center for Oceans and Human Health and Climate Change Interactions, University of South Carolina, Columbia, SC, United States
| | - Liyan Xiong
- Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, United States
| | - Gracie K. Anderson
- Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, United States
| | - Grace M. Astarita
- Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, United States
| | - Guoshuai Cai
- Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, United States
| | - Robert Sean Norman
- Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, United States
- Department of Environmental Health Sciences, NIEHS Center for Oceans and Human Health and Climate Change Interactions, University of South Carolina, Columbia, SC, United States
| | - Alan W. Decho
- Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, United States
- Department of Environmental Health Sciences, NIEHS Center for Oceans and Human Health and Climate Change Interactions, University of South Carolina, Columbia, SC, United States
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You Z, Li J, Wang Y, Wu D, Li F, Song H. Advances in mechanisms and engineering of electroactive biofilms. Biotechnol Adv 2023; 66:108170. [PMID: 37148984 DOI: 10.1016/j.biotechadv.2023.108170] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 03/22/2023] [Accepted: 05/02/2023] [Indexed: 05/08/2023]
Abstract
Electroactive biofilms (EABs) are electroactive microorganisms (EAMs) encased in conductive polymers that are secreted by EAMs and formed by the accumulation and cross-linking of extracellular polysaccharides, proteins, nucleic acids, lipids, and other components. EABs are present in the form of multicellular aggregates and play a crucial role in bioelectrochemical systems (BESs) for diverse applications, including biosensors, microbial fuel cells for renewable bioelectricity production and remediation of wastewaters, and microbial electrosynthesis of valuable chemicals. However, naturally occurred EABs are severely limited owing to their low electrical conductivity that seriously restrict the electron transfer efficiency and practical applications. In the recent decade, synthetic biology strategies have been adopted to elucidate the regulatory mechanisms of EABs, and to enhance the formation and electrical conductivity of EABs. Based on the formation of EABs and extracellular electron transfer (EET) mechanisms, the synthetic biology-based engineering strategies of EABs are summarized and reviewed as follows: (i) Engineering the structural components of EABs, including strengthening the synthesis and secretion of structural elements such as polysaccharides, eDNA, and structural proteins, to improve the formation of biofilms; (ii) Enhancing the electron transfer efficiency of EAMs, including optimizing the distribution of c-type cytochromes and conducting nanowire assembly to promote contact-based EET, and enhancing electron shuttles' biosynthesis and secretion to promote shuttle-mediated EET; (iii) Incorporating intracellular signaling molecules in EAMs, including quorum sensing systems, secondary messenger systems, and global regulatory systems, to increase the electron transfer flux in EABs. This review lays a foundation for the design and construction of EABs for diverse BES applications.
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Affiliation(s)
- Zixuan You
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Jianxun Li
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100093, China
| | - Yuxuan Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Deguang Wu
- Department of Brewing Engineering, Moutai Institute, Luban Ave, Renhuai 564507, Guizhou, PR China
| | - Feng Li
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Hao Song
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
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Presentato A, La Greca E, Consentino L, Alduina R, Liotta LF, Gruttadauria M. Antifouling Systems Based on a Polyhedral Oligomeric Silsesquioxane-Based Hexyl Imidazolium Salt Adsorbed on Copper Nanoparticles Supported on Titania. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13071291. [PMID: 37049384 PMCID: PMC10096683 DOI: 10.3390/nano13071291] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 03/31/2023] [Accepted: 04/03/2023] [Indexed: 06/12/2023]
Abstract
The reaction of octakis(3-chloropropyl)octasilsesquioxane with four equivalents of 1-hexylimidazole or 1-decylimidazole gave two products labelled as HQ-POSS (hexyl-imidazolium quaternized POSS) and DQ-POSS (decyl-imidazolium quaternized POSS) as regioisomer mixtures. An investigation of the biological activity of these two compounds revealed the higher antimicrobial performances of HQ-POSS against Gram-positive and Gram-negative microorganisms, proving its broad-spectrum activity. Due to its very viscous nature, HQ-POSS was adsorbed in variable amounts on the surface of biologically active oxides to gain advantages regarding the expendability of such formulations from an applicative perspective. Titania and 5 wt% Cu on titania were used as supports. The materials 10HQ-POSS/Ti and 15HQ-POSS/5CuTi strongly inhibited the ability of Pseudomonas PS27 cells-a bacterial strain described for its ability to handle very toxic organic solvents and perfluorinated compounds-to grow as planktonic cells. Moreover, the best formulations (i.e., 10HQ-POSS/Ti and 15HQ-POSS/5CuTi) could prevent Pseudomonas PS27 biofilm formation at a certain concentration (250 μg mL-1) which greatly impaired bacterial planktonic growth. Specifically, 15HQ-POSS/5CuTi completely impaired cell adhesion, thus successfully prejudicing biofilm formation and proving its suitability as a potential antifouling agent. Considering that most studies deal with quaternary ammonium salts (QASs) with long alkyl chains (>10 carbon atoms), the results reported here on hexylimidazolium-based POSS further deepen the knowledge of QAS formulations which can be used as antifouling compounds.
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Affiliation(s)
- Alessandro Presentato
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Viale Delle Scienze, Edificio 17, I-90128 Palermo, Italy; (A.P.); (L.C.); (R.A.)
| | - Eleonora La Greca
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN)-CNR, Via Ugo La Malfa 153, I-90146 Palermo, Italy;
| | - Luca Consentino
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Viale Delle Scienze, Edificio 17, I-90128 Palermo, Italy; (A.P.); (L.C.); (R.A.)
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN)-CNR, Via Ugo La Malfa 153, I-90146 Palermo, Italy;
| | - Rosa Alduina
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Viale Delle Scienze, Edificio 17, I-90128 Palermo, Italy; (A.P.); (L.C.); (R.A.)
| | - Leonarda Francesca Liotta
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN)-CNR, Via Ugo La Malfa 153, I-90146 Palermo, Italy;
| | - Michelangelo Gruttadauria
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Viale Delle Scienze, Edificio 17, I-90128 Palermo, Italy; (A.P.); (L.C.); (R.A.)
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The biofilm life cycle: expanding the conceptual model of biofilm formation. Nat Rev Microbiol 2022; 20:608-620. [PMID: 35922483 PMCID: PMC9841534 DOI: 10.1038/s41579-022-00767-0] [Citation(s) in RCA: 256] [Impact Index Per Article: 128.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2022] [Indexed: 01/18/2023]
Abstract
Bacterial biofilms are often defined as communities of surface-attached bacteria and are typically depicted with a classic mushroom-shaped structure characteristic of Pseudomonas aeruginosa. However, it has become evident that this is not how all biofilms develop, especially in vivo, in clinical and industrial settings, and in the environment, where biofilms often are observed as non-surface-attached aggregates. In this Review, we describe the origin of the current five-step biofilm development model and why it fails to capture many aspects of bacterial biofilm physiology. We aim to present a simplistic developmental model for biofilm formation that is flexible enough to include all the diverse scenarios and microenvironments where biofilms are formed. With this new expanded, inclusive model, we hereby introduce a common platform for developing an understanding of biofilms and anti-biofilm strategies that can be tailored to the microenvironment under investigation.
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Schwartzman JA, Ebrahimi A, Chadwick G, Sato Y, Roller BRK, Orphan VJ, Cordero OX. Bacterial growth in multicellular aggregates leads to the emergence of complex life cycles. Curr Biol 2022; 32:3059-3069.e7. [PMID: 35777363 PMCID: PMC9496226 DOI: 10.1016/j.cub.2022.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 05/03/2022] [Accepted: 06/07/2022] [Indexed: 01/12/2023]
Abstract
Facultative multicellular behaviors expand the metabolic capacity and physiological resilience of bacteria. Despite their ubiquity in nature, we lack an understanding of how these behaviors emerge from cellular-scale phenomena. Here, we show how the coupling between growth and resource gradient formation leads to the emergence of multicellular lifecycles in a marine bacterium. Under otherwise carbon-limited growth conditions, Vibrio splendidus 12B01 forms clonal multicellular groups to collectively harvest carbon from soluble polymers of the brown-algal polysaccharide alginate. As they grow, groups phenotypically differentiate into two spatially distinct sub-populations: a static "shell" surrounding a motile, carbon-storing "core." Differentiation of these two sub-populations coincides with the formation of a gradient in nitrogen-source availability within clusters. Additionally, we find that populations of cells containing a high proportion of carbon-storing individuals propagate and form new clusters more readily on alginate than do populations with few carbon-storing cells. Together, these results suggest that local metabolic activity and differential partitioning of resources leads to the emergence of reproductive cycles in a facultatively multicellular bacterium.
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Affiliation(s)
- Julia A Schwartzman
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Ali Ebrahimi
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Grayson Chadwick
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Yuya Sato
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan
| | - Benjamin R K Roller
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Center for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, Vienna 1030, Austria; Department of Environmental Systems Sciences, ETH Zürich, Universitätsstrasse 16, Zürich 8092, Switzerland; Department of Environmental Microbiology, Eawag, Ueberlandstrasse 133, Dübendorf 8600, Switzerland
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Otto X Cordero
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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11
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Geisel S, Secchi E, Vermant J. The role of surface adhesion on the macroscopic wrinkling of biofilms. eLife 2022; 11:76027. [PMID: 35723588 PMCID: PMC9208754 DOI: 10.7554/elife.76027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 06/01/2022] [Indexed: 12/14/2022] Open
Abstract
Biofilms, bacterial communities of cells encased by a self-produced matrix, exhibit a variety of three-dimensional structures. Specifically, channel networks formed within the bulk of the biofilm have been identified to play an important role in the colonies' viability by promoting the transport of nutrients and chemicals. Here, we study channel formation and focus on the role of the adhesion of the biofilm matrix to the substrate in Pseudomonas aeruginosa biofilms grown under constant flow in microfluidic channels. We perform phase contrast and confocal laser scanning microscopy to examine the development of the biofilm structure as a function of the substrates' surface energy. The formation of the wrinkles and folds is triggered by a mechanical buckling instability, controlled by biofilm growth rate and the film’s adhesion to the substrate. The three-dimensional folding gives rise to hollow channels that rapidly increase the effective volume occupied by the biofilm and facilitate bacterial movement inside them. The experiments and analysis on mechanical instabilities for the relevant case of a bacterial biofilm grown during flow enable us to predict and control the biofilm morphology.
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Affiliation(s)
- Steffen Geisel
- Laboratory for Soft Materials, Department of Materials, ETH Zurich, Zurich, Switzerland
| | - Eleonora Secchi
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Jan Vermant
- Laboratory for Soft Materials, Department of Materials, ETH Zurich, Zurich, Switzerland
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12
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Park S, Sauer K. Controlling Biofilm Development Through Cyclic di-GMP Signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:69-94. [PMID: 36258069 PMCID: PMC9891824 DOI: 10.1007/978-3-031-08491-1_3] [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] [Indexed: 01/11/2023]
Abstract
The cyclic di-GMP (c-di-GMP) second messenger represents a signaling system that regulates many bacterial behaviors and is of key importance for driving the lifestyle switch between motile loner cells and biofilm formers. This review provides an up-to-date summary of c-di-GMP pathways connected to biofilm formation by the opportunistic pathogen P. aeruginosa. Emphasis will be on the timing of c-di-GMP production over the course of biofilm formation, to highlight non-uniform and hierarchical increases in c-di-GMP levels, as well as biofilm growth conditions that do not conform with our current model of c-di-GMP.
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Affiliation(s)
- Soyoung Park
- Department of Biological Sciences, Binghamton University, Binghamton, NY, USA
- Binghamton Biofilm Research Center (BBRC), Binghamton University, Binghamton, NY, USA
| | - Karin Sauer
- Department of Biological Sciences, Binghamton University, Binghamton, NY, USA.
- Binghamton Biofilm Research Center (BBRC), Binghamton University, Binghamton, NY, USA.
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13
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Abstract
Careful attention to detail and adherence to procedure guidelines when inserting and managing intravascular catheters has decreased the incidence of catheter-related bloodstream infections (CRBSIs). In order to limit these, health professionals must understand the underlying microbiology. Biofilms can explain the clinical findings most often seen with CRBSIs, yet they are poorly understood within medicine. Bacteria growing on solid surfaces such as a catheter are predominantly in biofilm phenotype, with a group of genes active that allow the bacteria to be tolerant to antiseptics and antibiotics by producing a self-secreted protective matrix. It is unclear whether it is planktonic seeding or small fragments of biofilm breaking off into the bloodstream that eventually results in the acute infection. The literature identifies four routes for microbes to adhere to a catheter and start biofilm formation: catheter contact, catheter insertion, catheter management and non-catheter-related sources. Routine clinical culture methods are inadequate to fully identify microbes producing catheter biofilm and/or bloodstream infection, therefore DNA methods may be required to diagnose CRBSIs. Treatment is removal and reinsertion of the catheter in a different site when possible. However, antibiofilm strategies can be employed to try to salvage the catheter. The use of high-dose antiseptics or antibiotics for long durations inside the catheter and hub (antibiotic/antiseptic lock) can suppress biofilm enough to reduce the seeding of the blood below a level where the patient's immune system can prevent bloodstream infection.
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Affiliation(s)
- Randy Wolcott
- Physician, Southwest Regional Wound Care Center, Lubbock, Texas, USA
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14
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Davis S, Salowitz N, Beversdorf L, Silva MR. The Effect of Various Parameters on a Portable Sensor for the Detection of Thin Biofilms in Water Pipes. SENSORS (BASEL, SWITZERLAND) 2021; 21:4421. [PMID: 34203284 PMCID: PMC8271626 DOI: 10.3390/s21134421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 11/16/2022]
Abstract
The use of high-frequency strain waves to perform examinations and note measurements is referred to as ultrasonic testing (UT). UT is commonly used for the detection or evaluation of flaws and characterization of materials, among other applications. A standard ultrasonic inspection system comprises a pulser/receiver, transducer, and display devices. The pulser/receiver produces electrical pulses of high voltage. The transducer generates high-frequency ultrasonic energy after being driven by the pulser. The reflected wave is then converted into an electrical signal by the transducer and is displayed on a screen. The reflected signal strength versus the time plot helps to glean information regarding the features of a defect. In this paper, we discuss the experiments performed in a laboratory setting to determine ultrasound-based biofilm sensor sensitivity in relation to changes in the surrounding environment of temperature, concentration, turbidity, and conductivity of the liquid passing through the system. The effect of the change in frequency of the sensors was also studied. The sensors being developed are small and compact, portable, can be placed on the outer walls of the desired surface, use digital signal processing techniques, and the biofilm presence on the inner walls of the surface can be monitored.
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Affiliation(s)
- Sachin Davis
- Water Technology Accelerator (WaTA), University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA;
| | - Nathan Salowitz
- Department of Mechanical Engineering, College of Engineering and Applied Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA;
| | | | - Marcia R. Silva
- Water Technology Accelerator (WaTA), University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA;
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15
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Paraszkiewicz K, Moryl M, Płaza G, Bhagat D, K Satpute S, Bernat P. Surfactants of microbial origin as antibiofilm agents. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2021; 31:401-420. [PMID: 31509014 DOI: 10.1080/09603123.2019.1664729] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
The microbial world provides new energy sources and many various 'green' chemicals. One type of chemicals produced by microorganisms is the biosurfactant group. Biosurfactants are universal molecules, exhibiting surface properties often accompanied by desired biological activity. Biosurfactants are considered to be environmentally 'friendly' due to their low toxicity and biodegradable nature. These compounds have unique features and therefore they can find potential applications in many different industries, ranging from biotechnology to environmental remediation technologies. Antibacterial and antifungal activities make them relevant for applications as inhibitory agents against microbial biofilm. This review covers the current knowledge and the recent advances in the field of biosurfactants as antibiofilm agents.
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Affiliation(s)
- Katarzyna Paraszkiewicz
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Magdalena Moryl
- Department of Biology of Bacteria, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
| | - Grażyna Płaza
- Institute of Production Engineering, Faculty of Organization and Management, Silesian University of Technology, Zabrze, Poland
| | - Diksha Bhagat
- Department of Microbiology, Savitribai Phule Pune University, Pune, India
| | - Surekha K Satpute
- Department of Microbiology, Savitribai Phule Pune University, Pune, India
| | - Przemysław Bernat
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, Poland
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16
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Guzmán-Soto I, McTiernan C, Gonzalez-Gomez M, Ross A, Gupta K, Suuronen EJ, Mah TF, Griffith M, Alarcon EI. Mimicking biofilm formation and development: Recent progress in in vitro and in vivo biofilm models. iScience 2021; 24:102443. [PMID: 34013169 PMCID: PMC8113887 DOI: 10.1016/j.isci.2021.102443] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Biofilm formation in living organisms is associated to tissue and implant infections, and it has also been linked to the contribution of antibiotic resistance. Thus, understanding biofilm development and being able to mimic such processes is vital for the successful development of antibiofilm treatments and therapies. Several decades of research have contributed to building the foundation for developing in vitro and in vivo biofilm models. However, no such thing as an "all fit" in vitro or in vivo biofilm models is currently available. In this review, in addition to presenting an updated overview of biofilm formation, we critically revise recent approaches for the improvement of in vitro and in vivo biofilm models.
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Affiliation(s)
- Irene Guzmán-Soto
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, ON, K1Y4W7, Canada
| | - Christopher McTiernan
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, ON, K1Y4W7, Canada
| | - Mayte Gonzalez-Gomez
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, ON, K1Y4W7, Canada
| | - Alex Ross
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, ON, K1Y4W7, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON, K1H8M5, Canada
| | - Keshav Gupta
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, ON, K1Y4W7, Canada
| | - Erik J. Suuronen
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, ON, K1Y4W7, Canada
| | - Thien-Fah Mah
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON, K1H8M5, Canada
| | - May Griffith
- Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal, QC, H1T 2M4, Canada
- Département d'ophtalmologie, Université de Montréal, Montréal, QC, H3T1J4, Canada
| | - Emilio I. Alarcon
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, ON, K1Y4W7, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON, K1H8M5, Canada
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17
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18
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Bio-fabrication of titanium oxide nanoparticles from Ochradenus arabicus to obliterate biofilms of drug-resistant Staphylococcus aureus and Pseudomonas aeruginosa isolated from diabetic foot infections. APPLIED NANOSCIENCE 2021. [DOI: 10.1007/s13204-020-01630-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Peng J, Schachterle JK, Sundin GW. Orchestration of virulence factor expression and modulation of biofilm dispersal in Erwinia amylovora through activation of the Hfq-dependent small RNA RprA. MOLECULAR PLANT PATHOLOGY 2021; 22:255-270. [PMID: 33314618 PMCID: PMC7814967 DOI: 10.1111/mpp.13024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/09/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
Erwinia amylovora is the causative agent of the devastating disease fire blight of pome fruit trees. After infection of host plant leaves at apple shoot tips, E. amylovora cells form biofilms in xylem vessels, restrict water flow, and cause wilting symptoms. Although E. amylovora is well known to be able to cause systemic infection, how biofilm cells of E. amylovora transit from the sessile mode of growth in xylem to the planktonic mode of growth in cortical parenchyma remains unknown. Increasing evidence has suggested the important modulatory roles of Hfq-dependent small RNAs (sRNAs) in the pathogenesis of E. amylovora. Here, we demonstrate that the sRNA RprA acts as a positive regulator of amylovoran exopolysaccharide production, the type III secretion system (T3SS), and flagellar-dependent motility, and as a negative regulator of levansucrase activity and cellulose production. We also show that RprA affects the promoter activity of multiple virulence factor genes and regulates hrpS, a critical T3SS regulator, at the posttranscriptional level. We determined that rprA expression can be activated by the Rcs phosphorelay, and that expression is active during T3SS-mediated host infection in an immature pear fruit infection model. We further showed that overexpression of rprA activated the in vitro dispersal of E. amylovora cells from biofilms. Thus, our investigation of the varied role of RprA in affecting E. amylovora virulence provides important insights into the functions of this sRNA in biofilm control and systemic infection.
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Affiliation(s)
- Jingyu Peng
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
| | - Jeffrey K. Schachterle
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
- Present address:
US National Arboretum – Floral and Nursery Plants Research UnitUSDA‐ARSBeltsvilleMarylandUSA
| | - George W. Sundin
- Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMichiganUSA
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20
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Tian F, Li J, Nazir A, Tong Y. Bacteriophage - A Promising Alternative Measure for Bacterial Biofilm Control. Infect Drug Resist 2021; 14:205-217. [PMID: 33505163 PMCID: PMC7829120 DOI: 10.2147/idr.s290093] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 12/23/2020] [Indexed: 01/09/2023] Open
Abstract
Bacterial biofilms can enhance bacteria's viability by providing resistance against antibiotics and conventional disinfectants. The existence of biofilm is a serious threat to human health, causing incalculable loss. Therefore, new strategies to deal with bacterial biofilms are needed. Bacteriophages are unique due to their activity on bacteria and do not pose a threat to humans. Consequently, they are considered safe alternatives to drugs for the treatment of bacterial diseases. They can effectively obliterate bacterial biofilms and have great potential in medical treatment, the food industry, and pollution control. There are intricate mechanisms of interaction between phages and biofilms. Biofilms may prevent the invasion of phages, and phages can kill bacteria for biofilm control purposes or influence the formation of biofilms. At present, there are various measures for the prevention and control of biofilms through phages, including the combined use of drugs and the application of phage cocktails. This article mainly reviews the function and formation process of bacterial biofilms, summarizes the different mechanisms between phages and biofilms, briefly explains the phage usage for the control of bacterial biofilms, and promotes phage application maintenance human health and the protection of the natural environment.
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Affiliation(s)
- Fengjuan Tian
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
| | - Jing Li
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
| | - Amina Nazir
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
| | - Yigang Tong
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
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21
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Abstract
The formation of microbial biofilms enables single planktonic cells to assume a multicellular mode of growth. During dispersion, the final step of the biofilm life cycle, single cells egress from the biofilm to resume a planktonic lifestyle. As the planktonic state is considered to be more vulnerable to antimicrobial agents and immune responses, dispersion is being considered a promising avenue for biofilm control. In this Review, we discuss conditions that lead to dispersion and the mechanisms by which native and environmental cues contribute to dispersion. We also explore recent findings on the role of matrix degradation in the dispersion process, and the distinct phenotype of dispersed cells. Last, we discuss the translational and therapeutic potential of dispersing bacteria during infection.
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Affiliation(s)
- Kendra P Rumbaugh
- Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Department of the TTUHSC Surgery Burn Center of Research Excellence, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Karin Sauer
- Department of Biological Sciences, Binghamton University, Binghamton, NY, USA.
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY, USA.
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22
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Geddes-McAlister J, Kugadas A, Gadjeva M. Tasked with a Challenging Objective: Why Do Neutrophils Fail to Battle Pseudomonas aeruginosa Biofilms. Pathogens 2019; 8:pathogens8040283. [PMID: 31817091 PMCID: PMC6963930 DOI: 10.3390/pathogens8040283] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/26/2019] [Accepted: 12/02/2019] [Indexed: 01/28/2023] Open
Abstract
Multidrug-resistant (MDR) bacterial infections are a leading cause of mortality, affecting approximately 250,000 people in Canada and over 2 million people in the United States, annually. The lack of efficacy of antibiotic-based treatments is often caused by inability of the drug to penetrate bacterial biofilms in sufficient concentrations, posing a major therapeutic challenge. Here, we review the most recent information about the architecture of Pseudomonas aeruginosa biofilms in vivo and describe how advances in imaging and mass spectroscopy analysis bring about novel therapeutic options and challenge existing dogmas.
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Affiliation(s)
| | - Abirami Kugadas
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
| | - Mihaela Gadjeva
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
- Correspondence: ; Tel.: +1-617-525-2268; Fax: +1-617-525-2510
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23
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Im H, Kwon H, Cho G, Kwon J, Choi SY, Mitchell RJ. Viscosity has dichotomous effects on Bdellovibrio bacteriovorus HD100 predation. Environ Microbiol 2019; 21:4675-4684. [PMID: 31498968 DOI: 10.1111/1462-2920.14799] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 09/05/2019] [Indexed: 11/28/2022]
Abstract
Bdellovibrio bacteriovorus HD100 is a highly motile predatory bacterium that consumes other Gram-negative bacteria for its sustenance. Here, we describe the impacts the media viscosity has both on the motility of predator and its attack rates. Experiments performed in polyethylene glycol (PEG) solutions, a linear polymer, found a viscosity of 10 mPa s (5% PEG) negatively impacted predation over a 24-h period. When the viscosity was increased to 27 mPa s (10% PEG), predation was nearly abolished. Tests with three other B. bacteriovorus strains, i.e., 109J and two natural isolates, found identical results. Short-term (2-h) experiments, however, found attack rates were improved in 1% PEG, which had a viscosity of 5.4 mPa s, using bioluminescent prey and their viabilities. In contrast, when experiments were performed in dextran, a branched polymer, no increase in predation was seen even though the viscosity was a comparable 5.1 mPa s. The enhanced attack rates in this solution coincided with a 31% increase in B. bacteriovorus HD100 swimming speeds (62 μm s-1 in 1% PEG vs. 47.5 μm s-1 in HEPES-salt).
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Affiliation(s)
- Hansol Im
- Division of Biological Sciences, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, South Korea
| | - Heeun Kwon
- Division of Biological Sciences, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, South Korea
| | - Gayoung Cho
- Division of Biological Sciences, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, South Korea
| | - Jisoo Kwon
- Division of Biological Sciences, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, South Korea
| | - Seong Yeol Choi
- Division of Biological Sciences, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, South Korea
| | - Robert J Mitchell
- Division of Biological Sciences, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, South Korea
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24
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Ebrahimi A, Schwartzman J, Cordero OX. Multicellular behaviour enables cooperation in microbial cell aggregates. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190077. [PMID: 31587643 PMCID: PMC6792450 DOI: 10.1098/rstb.2019.0077] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Oligosaccharides produced from the extracellular hydrolysis of biological materials can act as common goods that promote cooperative growth in microbial populations, whereby cell–cell aggregation increases both the per capita availability of resources and the per-cell growth rate. However, aggregation can also have detrimental consequences for growth, as gradients form within aggregates limiting the resource accessibility. We built a computational model, which predicts cooperation is restricted in dense cell aggregates larger than 10 µm because of the emergence of polymer and oligomer counter gradients. We compared these predictions to experiments performed with two well-studied alginate-degrading strains of Vibrio splendidus, which varied in their ability to secrete alginate lyase. We observed that both strains can form large aggregates (less than 50 µm), overcoming diffusion limitation by rearranging their internal structure. The stronger enzyme producer grew non-cooperatively and formed aggregates with internal channels that allowed exchange between the bulk environment and the aggregate, whereas the weak enzyme producer showed strongly cooperative growth and formed dense aggregates in which cells near the core mixed by active swimming. Our simulations suggest that the mixing and channelling reduce diffusion limitation and allow cells to uniformly grow in aggregates. Together, these data demonstrate that bacterial behaviour can help overcome competition imposed by resource gradients within cell aggregates. This article is part of a discussion meeting issue ‘Single cell ecology’.
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Affiliation(s)
- Ali Ebrahimi
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Julia Schwartzman
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Otto X Cordero
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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25
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Deliorman M, Duatepe FPG, Davenport EK, Fransson BA, Call DR, Beyenal H, Abu-Lail NI. Responses of Acinetobacter baumannii Bound and Loose Extracellular Polymeric Substances to Hyperosmotic Agents Combined with or without Tobramycin: An Atomic Force Microscopy Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:9071-9083. [PMID: 31184900 PMCID: PMC7607972 DOI: 10.1021/acs.langmuir.9b01227] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
In this work, contributions of extracellular polymeric substances (EPS) to the nanoscale mechanisms through which the multidrug-resistant Acinetobacter baumannii responds to antimicrobial and hyperosmotic treatments were investigated by atomic force microscopy. Specifically, the adhesion strengths to a control surface of silicon nitride (Si3N4) and the lengths of bacterial surface biopolymers of bound and loose EPS extracted from A. baumannii biofilms were quantified after individual or synergistic treatments with hyperosmotic agents (NaCl and maltodextrin) and an antibiotic (tobramycin). In the absence of any treatment, the loose EPS were significantly longer in length and higher in adhesion to Si3N4 than the bound EPS. When used individually, the hyperosmotic agents and tobramycin collapsed the A. baumannii bound and loose EPS. The combined treatment of maltodextrin with tobramycin collapsed only the loose EPS and did not alter the adhesion of both bound and loose EPS to Si3N4. In addition, the combined treatment was not as effective in collapsing the EPS molecules as when tobramycin was applied alone. Finally, the effects of treatments were dose-dependent. Altogether, our findings suggest that a sequential treatment could be effective in treating A. baumannii biofilms, in which a hyperosmotic agent is used first to collapse the EPS and limit the diffusion of nutrients into the biofilm, followed by the use of an antibiotic to kill the bacterial cells that escape from the biofilm because of starvation.
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Affiliation(s)
- Muhammedin Deliorman
- Division of Engineering, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, UAE
| | | | - Emily K. Davenport
- Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, 99164 Pullman, Washington, United States
| | - Boel A. Fransson
- Department of Veterinary Clinical Sciences, Washington State University, 99164 Pullman, Washington, United States
| | - Douglas R. Call
- Paul G. Allen School for Global Animal Health, Washington State University, 99164 Pullman, Washington, United States
| | - Haluk Beyenal
- Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, 99164 Pullman, Washington, United States
| | - Nehal I. Abu-Lail
- Department of Biomedical Engineering, University of Texas at San Antonio, 78249 San Antonio, Texas, United States
- Corresponding Author:. Phone: +1 210 458 8131
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26
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Qi L, Christopher GF. Role of Flagella, Type IV Pili, Biosurfactants, and Extracellular Polymeric Substance Polysaccharides on the Formation of Pellicles by Pseudomonas aeruginosa. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:5294-5304. [PMID: 30883129 DOI: 10.1021/acs.langmuir.9b00271] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Microbial biofilms are viscoelastic materials formed by bacteria, which occur on solid surfaces, at liquid interfaces, or in free solution. Although solid surface biofilms have been widely studied, pellicles, biofilms at liquid interfaces, have had significantly less focus. In this work, interfacial shear rheology and scanning electron microscopy imaging are used to characterize how flagella, type IV pili, biosurfactants, and extracellular polymeric substance polysaccharides affect the formation of pellicles by Pseudomonas aeruginosa at an air/water interface. Pellicles still form with the loss of a single biological attachment mechanism, which is hypothesized to be due to surface tension-aided attachment. Changes in the surface structure of the pellicles are observed when changing both the function/structure of type IV pili, removing the flagella, or stopping the expression of biosurfactants. However, these changes do not appear to affect pellicle elasticity in a consistent way. Traits that affect adsorption and growth/spreading appear to affect pellicles in a manner consistent with literature results for solid surface biofilms; small differences are seen in attachment-related mechanisms, which may occur due to surface tension.
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Affiliation(s)
- Lingjuan Qi
- Department of Mechanical Engineering , Texas Tech University , Lubbock 79409 , United States
| | - Gordon F Christopher
- Department of Mechanical Engineering , Texas Tech University , Lubbock 79409 , United States
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Pyruvate-depleting conditions induce biofilm dispersion and enhance the efficacy of antibiotics in killing biofilms in vitro and in vivo. Sci Rep 2019; 9:3763. [PMID: 30842579 PMCID: PMC6403282 DOI: 10.1038/s41598-019-40378-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 02/14/2019] [Indexed: 01/09/2023] Open
Abstract
The formation of biofilms is a developmental process initiated by planktonic cells transitioning to the surface, which comes full circle when cells disperse from the biofilm and transition to the planktonic mode of growth. Considering that pyruvate has been previously demonstrated to be required for the formation of P. aeruginosa biofilms, we asked whether pyruvate likewise contributes to the maintenance of the biofilm structure, with depletion of pyruvate resulting in dispersion. Here, we demonstrate that the enzymatic depletion of pyruvate coincided with the dispersion of established biofilms by S. aureus and laboratory and clinical P. aeruginosa isolates. The dispersion response was dependent on pyruvate fermentation pathway components but independent of proteins previously described to contribute to P. aeruginosa biofilm dispersion. Using porcine second-degree burn wounds infected with P. aeruginosa biofilm cells, we furthermore demonstrated that pyruvate depletion resulted in a reduction of biofilm biomass in vivo. Pyruvate-depleting conditions enhanced the efficacy of tobramycin killing of the resident wound biofilms by up to 5-logs. Our findings strongly suggest the management of pyruvate availability to be a promising strategy to combat biofilm-related infections by two principal pathogens associated with wound and cystic fibrosis lung infections.
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Mathematical modeling of dispersal phenomenon in biofilms. Math Biosci 2019; 307:70-87. [DOI: 10.1016/j.mbs.2018.07.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 12/05/2017] [Accepted: 07/24/2018] [Indexed: 02/05/2023]
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Regulation of Biofilm Aging and Dispersal in Bacillus subtilis by the Alternative Sigma Factor SigB. J Bacteriol 2018; 201:JB.00473-18. [PMID: 30396900 DOI: 10.1128/jb.00473-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 10/25/2018] [Indexed: 11/20/2022] Open
Abstract
Bacterial biofilms are important in natural settings, biotechnology, and medicine. However, regulation of biofilm development and its persistence in different niches is complex and only partially understood. One key step during the biofilm life cycle is dispersal, when motile cells abandon the mature biofilm to spread out and colonize new niches. Here, we show that in the model bacterium Bacillus subtilis the general stress transcription factor SigB is essential for halting detrimental overgrowth of mature biofilm and for triggering dispersal when nutrients become limited. Specifically, SigB-deficient biofilms were larger than wild-type biofilms but exhibited accelerated cell death, significantly greater sensitivity to different stresses, and reduced dispersal. Interestingly, the signal detected by SigB to limit biofilm growth was transduced through the RsbP-dependent metabolic arm of the SigB regulatory cascade, which in turn positively controlled expression of SinR, the master regulator of biofilm formation and cell motility. This novel SigB-SinR regulatory circuit might be important in controlling the fitness of biofilms (either beneficial or harmful) in diverse environments.IMPORTANCE Biofilms are crucial for bacterial survival, adaptation, and dissemination in natural, industrial, and medical systems. Sessile cells embedded in the self-produced extracellular matrix of the biofilm benefit from a division of labor and are protected from environmental insults. However, as the biofilm ages, cells become stressed because of overcrowding, starvation, and accumulation of waste products. How does the sessile biofilm community sense and respond to stressful conditions? Here, we show that in Bacillus subtilis, the transcription factors SigB and SinR control whether cells remain in or leave a biofilm when metabolic conditions become unfavorable. This novel SigB-SinR regulatory circuit might be important for controlling the fitness of biofilms (either beneficial or harmful) in diverse environments.
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Roy R, Tiwari M, Donelli G, Tiwari V. Strategies for combating bacterial biofilms: A focus on anti-biofilm agents and their mechanisms of action. Virulence 2018; 9:522-554. [PMID: 28362216 PMCID: PMC5955472 DOI: 10.1080/21505594.2017.1313372] [Citation(s) in RCA: 685] [Impact Index Per Article: 114.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Biofilm refers to the complex, sessile communities of microbes found either attached to a surface or buried firmly in an extracellular matrix as aggregates. The biofilm matrix surrounding bacteria makes them tolerant to harsh conditions and resistant to antibacterial treatments. Moreover, the biofilms are responsible for causing a broad range of chronic diseases and due to the emergence of antibiotic resistance in bacteria it has really become difficult to treat them with efficacy. Furthermore, the antibiotics available till date are ineffective for treating these biofilm related infections due to their higher values of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), which may result in in-vivo toxicity. Hence, it is critically important to design or screen anti-biofilm molecules that can effectively minimize and eradicate biofilm related infections. In the present article, we have highlighted the mechanism of biofilm formation with reference to different models and various methods used for biofilm detection. A major focus has been put on various anti-biofilm molecules discovered or tested till date which may include herbal active compounds, chelating agents, peptide antibiotics, lantibiotics and synthetic chemical compounds along with their structures, mechanism of action and their respective MICs, MBCs, minimum biofilm inhibitory concentrations (MBICs) as well as the half maximal inhibitory concentration (IC50) values available in the literature so far. Different mode of action of anti biofilm molecules addressed here are inhibition via interference in the quorum sensing pathways, adhesion mechanism, disruption of extracellular DNA, protein, lipopolysaccharides, exopolysaccharides and secondary messengers involved in various signaling pathways. From this study, we conclude that the molecules considered here might be used to treat biofilm-associated infections after significant structural modifications, thereby investigating its effective delivery in the host. It should also be ensured that minimum effective concentration of these molecules must be capable of eradicating biofilm infections with maximum potency without posing any adverse side effects on the host.
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Affiliation(s)
- Ranita Roy
- a Department of Biochemistry , Central University of Rajasthan , Ajmer , India
| | - Monalisa Tiwari
- a Department of Biochemistry , Central University of Rajasthan , Ajmer , India
| | - Gianfranco Donelli
- b Microbial Biofilm Laboratory, IRCCS Fondazione Santa Lucia , Rome , Italy
| | - Vishvanath Tiwari
- a Department of Biochemistry , Central University of Rajasthan , Ajmer , India
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Abu Bakar M, McKimm J, Haque SZ, Majumder MAA, Haque M. Chronic tonsillitis and biofilms: a brief overview of treatment modalities. J Inflamm Res 2018; 11:329-337. [PMID: 30233227 PMCID: PMC6134941 DOI: 10.2147/jir.s162486] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recurrent tonsillitis is described as when an individual suffers from several attacks of tonsillitis per year. Chronic and recurrent tonsillitis both cause repeated occurrences of inflamed tonsils which have a significant impact on a patient's quality of life. Numerous children suffer from recurrent tonsillitis and sore throats, and these illnesses become part of their life. Antimicrobials can provide temporary relief, but in many cases, tonsillitis recurs. The cause of such recurrent infections have been identified as microorganisms which often create biofilms and a repository of infection in the wet and warm folds of the tonsils. This review discusses different treatment modalities, their advantages and disadvantages, and new treatment options focusing on biofilms. All treatment options should be selected based on evidence and individual need.
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Affiliation(s)
- Muhamad Abu Bakar
- Faculty of Medicine and Defence Health, Universiti Pertahanan Nasional Malaysia (National Defence University of Malaysia), Kuala Lumpur, Malaysia,
| | - Judy McKimm
- Swansea University School of Medicine, Swansea University, Swansea, wales, UK
| | | | | | - Mainul Haque
- Faculty of Medicine and Defence Health, Universiti Pertahanan Nasional Malaysia (National Defence University of Malaysia), Kuala Lumpur, Malaysia,
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Haagensen J, Verotta D, Huang L, Engel J, Spormann AM, Yang K. Spatiotemporal pharmacodynamics of meropenem- and tobramycin-treated Pseudomonas aeruginosa biofilms. J Antimicrob Chemother 2018; 72:3357-3365. [PMID: 28961810 DOI: 10.1093/jac/dkx288] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 07/17/2017] [Indexed: 01/07/2023] Open
Abstract
Objectives The selection and dose of antibiotic therapy for biofilm-related infections are based on traditional pharmacokinetic studies using planktonic bacteria. The objective of this study was to characterize the time course and spatial activity of human exposure levels of meropenem and tobramycin against Pseudomonas aeruginosa biofilms grown in an in vitro flow-chamber model. Methods Pharmacokinetic profiles of meropenem and tobramycin used in human therapy were administered to GFP-labelled P. aeruginosa PAO1 grown in flow chambers for 24 or 72 h. Images were acquired using confocal laser scanning microscopy throughout antibiotic treatment. Bacterial biomass was measured using COMSTAT and pharmacokinetic/pharmacodynamic models were fitted using NONMEM7. Results Meropenem treatment resulted in more rapid and sustained killing of both the 24 and 72 h PAO1 biofilm compared with tobramycin. Biofilm regrowth after antibiotic treatment occurred fastest with tobramycin. Meropenem preferentially killed subpopulations within the mushroom cap of the biofilms, regardless of biofilm maturity. The spatial killing by tobramycin varied with biofilm maturity. A tobramycin-treated 24 h biofilm resulted in live and dead cells detaching from the biofilm, while treatment of a 72 h biofilm preferentially killed subpopulations on the periphery of the mushroom stalk. Regrowth occurred primarily on the mushroom caps. Combination meropenem and tobramycin therapy resulted in rapid and efficient killing of biofilm cells, with a spatial pattern similar to meropenem alone. Conclusions Simulated human concentrations of meropenem and tobramycin in young and mature PAO1 biofilms exhibited differences in temporal and spatial patterns of killing and antibiotic tolerance development.
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Affiliation(s)
- Janus Haagensen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs Lyngby, Denmark
| | - Davide Verotta
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco School of Pharmacy, San Francisco, CA 94143, USA
| | - Liusheng Huang
- Department of Clinical Pharmacy, University of California San Francisco School of Pharmacy, San Francisco, CA 94143, USA
| | - Joanne Engel
- Departments of Medicine and Microbiology/Immunology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Alfred M Spormann
- Department of Civil and Environmental Engineering, James H. Clark Center, Stanford University, Stanford, CA 94305, USA
| | - Katherine Yang
- Department of Clinical Pharmacy, University of California San Francisco School of Pharmacy, San Francisco, CA 94143, USA
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Lotfy WA, Atalla RG, Sabra WA, El-Helow ER. Expression of extracellular polysaccharides and proteins by clinical isolates of Pseudomonas aeruginosa in response to environmental conditions. Int Microbiol 2018; 21:129-142. [PMID: 30810953 DOI: 10.1007/s10123-018-0010-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 05/13/2018] [Accepted: 05/14/2018] [Indexed: 11/25/2022]
Abstract
The opportunistic pathogen Pseudomonas aeruginosa causes chronic respiratory infections in patients with cystic fibrosis (CF). Persistence of this bacterium is attributed to its ability to form biofilms which rely on an extracellular polymeric substance matrix. Extracellular polysaccharides (EPS) and secreted proteins are key matrix components of P. aeruginosa biofilms. Recently, nebulized magnesium sulfate has been reported as a significant bronchodilator for asthmatic patients including CF. However, the impact of magnesium sulfate on the virulence effect of P. aeruginosa is lacking. In this report, we investigated the influence of magnesium sulfate and other environmental factors on the synthesis of alginate and secretion of proteins by a mucoid and a non-mucoid strain of P. aeruginosa, respectively. By applying the Plackett-Burman and Box-Behnken experimental designs, we found that phosphates (6.0 g/l), ammonium sulfate (4.0 g/l), and trace elements (0.6 mg/l) markedly supported alginate production by the mucoid strain. However, ferrous sulfate (0.3 mg/l), magnesium sulfate (0.02 g/l), and phosphates (6.0 g/l) reinforced the secretion of proteins by the non-mucoid strain.
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Affiliation(s)
- Walid A Lotfy
- Microbiology Department, Faculty of Dentistry, Pharos University in Alexandria, Alexandria, Egypt.
| | - Ramy G Atalla
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Wael A Sabra
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Ehab R El-Helow
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, Egypt
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Sadrearhami Z, Nguyen TK, Namivandi-Zangeneh R, Jung K, Wong EHH, Boyer C. Recent advances in nitric oxide delivery for antimicrobial applications using polymer-based systems. J Mater Chem B 2018; 6:2945-2959. [PMID: 32254331 DOI: 10.1039/c8tb00299a] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The nitric oxide (NO) molecule has gained increasing attention in biological applications to combat biofilm-associated bacterial infections. However, limited NO loading, relatively short half-lives of low molecular weight NO donor compounds, and difficulties in targeted delivery of NO have hindered their practical clinical administration. To overcome these drawbacks, the combination of NO and scaffolds based on biocompatible polymers is an effective way towards realizing the practical utility of NO in biomedical applications. In this regard, the present overview highlights the recent developments in NO-releasing polymeric biomaterials for antimicrobial applications, focusing on antibiofilm treatments and the challenges that need to be overcome.
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Affiliation(s)
- Zahra Sadrearhami
- Centre for Advanced Macromolecular Design (CAMD) and Australian Centre for NanoMedicine (ACN), School of Chemical Engineering, UNSW Australia, Sydney, NSW 2052, Australia.
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Skariyachan S, Sridhar VS, Packirisamy S, Kumargowda ST, Challapilli SB. Recent perspectives on the molecular basis of biofilm formation by Pseudomonas aeruginosa and approaches for treatment and biofilm dispersal. Folia Microbiol (Praha) 2018; 63:413-432. [PMID: 29352409 DOI: 10.1007/s12223-018-0585-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Accepted: 01/12/2018] [Indexed: 12/25/2022]
Abstract
Pseudomonas aeruginosa, a Gram-negative, rod-shaped bacterium causes widespread diseases in humans. This bacterium is frequently related to nosocomial infections such as pneumonia, urinary tract infections (UTIs) and bacteriaemia especially in immunocompromised patients. The current review focuses on the recent perspectives on biofilms formation by these bacteria. Biofilms are communities of microorganisms in which cells stick to each other and often adhere to a surface. These adherent cells are usually embedded within a self-produced matrix of extracellular polymeric substance (EPS). Pel, psl and alg operons present in P. aeruginosa are responsible for the biosynthesis of extracellular polysaccharide which plays an important role in cell surface interactions during biofilm formation. Recent studies suggested that cAMP signalling pathway, quorum-sensing pathway, Gac/Rsm pathway and c-di-GMP signalling pathway are the main mechanism that leads to the biofilm formation. Understanding the bacterial virulence depends on a number of cell-associated and extracellular factors and is very essential for the development of potential drug targets. Thus, the review focuses on the major genes involved in the biofilm formation, the state of art update on the biofilm treatment and the dispersal approaches such as targeting adhesion and maturation, targeting virulence factors and other strategies such as small molecule-based inhibitors, phytochemicals, bacteriophage therapy, photodynamic therapy, antimicrobial peptides and natural therapies and vaccines to curtail the biofilm formation by P. aeruginosa.
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Affiliation(s)
- Sinosh Skariyachan
- Department of Biotechnology, R & D Centre, Dayananda Sagar College of Engineering, Bangalore, Karnataka, 560 078, India.
| | - Vaishnavi Sneha Sridhar
- Department of Biotechnology, R & D Centre, Dayananda Sagar College of Engineering, Bangalore, Karnataka, 560 078, India
| | - Swathi Packirisamy
- Department of Biotechnology, R & D Centre, Dayananda Sagar College of Engineering, Bangalore, Karnataka, 560 078, India
| | - Supreetha Toplar Kumargowda
- Department of Biotechnology, R & D Centre, Dayananda Sagar College of Engineering, Bangalore, Karnataka, 560 078, India
| | - Sneha Basavaraj Challapilli
- Department of Biotechnology, R & D Centre, Dayananda Sagar College of Engineering, Bangalore, Karnataka, 560 078, India
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Abstract
One common feature of biofilm development is the active dispersal of cells from the mature biofilm, which completes the biofilm life cycle and allows for the subsequent colonization of new habitats. Dispersal is likely to be critical for species survival and appears to be a precisely regulated process that involves a complex network of genes and signal transduction systems. Sophisticated molecular mechanisms control the transition of sessile biofilm cells into dispersal cells and their coordinated detachment and release in the bulk liquid. Dispersal cells appear to be specialized and exhibit a unique phenotype different from biofilm or planktonic bacteria. Further, the dispersal population is characterized by a high level of heterogeneity, reminiscent of, but distinct from, that in the biofilm, which could potentially allow for improved colonization under various environmental conditions. Here we review recent advances in characterizing the molecular mechanisms that regulate biofilm dispersal events and the impact of dispersal in a broader ecological context. Several strategies that exploit the mechanisms controlling biofilm dispersal to develop as applications for biofilm control are also presented.
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Abedon ST. Phage "delay" towards enhancing bacterial escape from biofilms: a more comprehensive way of viewing resistance to bacteriophages. AIMS Microbiol 2017; 3:186-226. [PMID: 31294157 PMCID: PMC6605007 DOI: 10.3934/microbiol.2017.2.186] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 03/17/2017] [Indexed: 12/15/2022] Open
Abstract
In exploring bacterial resistance to bacteriophages, emphasis typically is placed on those mechanisms which completely prevent phage replication. Such resistance can be detected as extensive reductions in phage ability to form plaques, that is, reduced efficiency of plating. Mechanisms include restriction-modification systems, CRISPR/Cas systems, and abortive infection systems. Alternatively, phages may be reduced in their “vigor” when infecting certain bacterial hosts, that is, with phages displaying smaller burst sizes or extended latent periods rather than being outright inactivated. It is well known, as well, that most phages poorly infect bacteria that are less metabolically active. Extracellular polymers such as biofilm matrix material also may at least slow phage penetration to bacterial surfaces. Here I suggest that such “less-robust” mechanisms of resistance to bacteriophages could serve bacteria by slowing phage propagation within bacterial biofilms, that is, delaying phage impact on multiple bacteria rather than necessarily outright preventing such impact. Related bacteria, ones that are relatively near to infected bacteria, e.g., roughly 10+ µm away, consequently may be able to escape from biofilms with greater likelihood via standard dissemination-initiating mechanisms including erosion from biofilm surfaces or seeding dispersal/central hollowing. That is, given localized areas of phage infection, so long as phage spread can be reduced in rate from initial points of contact with susceptible bacteria, then bacterial survival may be enhanced due to bacteria metaphorically “running away” to more phage-free locations. Delay mechanisms—to the extent that they are less specific in terms of what phages are targeted—collectively could represent broader bacterial strategies of phage resistance versus outright phage killing, the latter especially as require specific, evolved molecular recognition of phage presence. The potential for phage delay should be taken into account when developing protocols of phage-mediated biocontrol of biofilm bacteria, e.g., as during phage therapy of chronic bacterial infections.
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Affiliation(s)
- Stephen T Abedon
- Department of Microbiology, the Ohio State University, 1680 University Dr., Mansfield, OH 44906, USA
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Nair HAS, Periasamy S, Yang L, Kjelleberg S, Rice SA. Real Time, Spatial, and Temporal Mapping of the Distribution of c-di-GMP during Biofilm Development. J Biol Chem 2016; 292:477-487. [PMID: 27899451 DOI: 10.1074/jbc.m116.746743] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 11/28/2016] [Indexed: 11/06/2022] Open
Abstract
Bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) is a dynamic intracellular signaling molecule that plays a central role in the biofilm life cycle. Current methodologies for the quantification of c-di-GMP are typically based on chemical extraction, representing end point measurements. Chemical methodologies also fail to take into consideration the physiological heterogeneity of the biofilm and thus represent an average c-di-GMP concentration across the entire biofilm. To address these problems, a ratiometric, image-based quantification method has been developed based on expression of the green fluorescence protein (GFP) under the control of the c-di-GMP-responsive cdrA promoter (Rybtke, M. T., Borlee, B. R., Murakami, K., Irie, Y., Hentzer, M., Nielsen, T. E., Givskov, M., Parsek, M. R., and Tolker-Nielsen, T. (2012) Appl. Environ. Microbiol. 78, 5060-5069). The methodology uses the cyan fluorescent protein (CFP) as a biomass indicator and the GFP as a c-di-GMP reporter. Thus, the CFP/GFP ratio gives the effective c-di-GMP per biomass. A binary mask was applied to alleviate background fluorescence, and fluorescence was calibrated against known c-di-GMP concentrations. Using flow cells for biofilm formation, c-di-GMP showed a non-uniform distribution across the biofilm, with concentrated hot spots of c-di-GMP. Additionally, c-di-GMP was found to be localized at the outer boundary of mature colonies in contrast to a uniform distribution in early stage, small colonies. These data demonstrate the application of a method for the in situ, real time quantification of c-di-GMP and show that the amount of this biofilm-regulating second messenger was dynamic with time and colony size, reflecting the extent of biofilm heterogeneity in real time.
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Affiliation(s)
- Harikrishnan A S Nair
- From the Singapore Centre for Environmental Life Sciences Engineering.,Interdisciplinary Graduate School, and
| | | | - Liang Yang
- From the Singapore Centre for Environmental Life Sciences Engineering.,School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Staffan Kjelleberg
- From the Singapore Centre for Environmental Life Sciences Engineering.,School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Scott A Rice
- From the Singapore Centre for Environmental Life Sciences Engineering, .,School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
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Bhattacharjee A, Nusca TD, Hochbaum AI. Rhamnolipids Mediate an Interspecies Biofilm Dispersal Signaling Pathway. ACS Chem Biol 2016; 11:3068-3076. [PMID: 27623227 DOI: 10.1021/acschembio.6b00750] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bacterial biofilms are problematic in natural and anthropogenic environments, and they confer protective properties on their constituent cells, making them difficult to treat with conventional antibiotics. Antibiofilm strategies, therefore, represent a promising direction of research for treating biofilm infections. Natural autodispersal and interspecies dispersal signaling pathways provide insight into cell-cell communication mechanisms, species dynamics in mixed communities, and potential targets for infection therapies. Here, we describe a novel interspecies dispersal signaling pathway between Pseudomonas aeruginosa and Escherichia coli. E. coli biofilms disperse in response to compounds in P. aeruginosa culture supernatant. Two components of the P. aeruginosa Las and Rhl quorum sensing systems, N-(3-oxo-dodecanoyl) homoserine lactone (3oxoC12HSL) and rhamnolipids, are found to act cooperatively to disperse E. coli biofilms. Our results indicate that rhamnolipids do not affect growth, biofilm development, or dispersal in E. coli but instead complement 3oxoC12HSL signaling by inducing selective permeability of the E. coli membrane. The increased target cell permeability is consistent with rhamnolipid-mediated removal of lipopolysaccharide from E. coli membranes and appears to selectively increase the permeability of lipophilic acyl homoserine lactones. This work suggests that rhamnolipids play a critical role in P. aeruginosa-E. coli interspecies signaling. Rhamnolipids and other biosurfactants may have similar effects in other intra- and interspecies chemical signaling pathways.
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Affiliation(s)
- Arunima Bhattacharjee
- Department
of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, United States
| | - Tyler D. Nusca
- Department
of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, United States
| | - Allon I. Hochbaum
- Department
of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, United States
- Department
of Chemistry, University of California, Irvine, Irvine, California 92697, United States
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Abstract
Candida albicans, the most pervasive fungal pathogen that colonizes humans, forms biofilms that are architecturally complex. They consist of a basal yeast cell polylayer and an upper region of hyphae encapsulated in extracellular matrix. However, biofilms formed in vitro vary as a result of the different conditions employed in models, the methods used to assess biofilm formation, strain differences, and, in a most dramatic fashion, the configuration of the mating type locus (MTL). Therefore, integrating data from different studies can lead to problems of interpretation if such variability is not taken into account. Here we review the conditions and factors that cause biofilm variation, with the goal of engendering awareness that more attention must be paid to the strains employed, the methods used to assess biofilm development, every aspect of the model employed, and the configuration of the MTL locus. We end by posing a set of questions that may be asked in comparing the results of different studies and developing protocols for new ones. This review should engender the notion that not all biofilms are created equal.
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Affiliation(s)
- David R Soll
- Developmental Studies Hybridoma Bank, Department of Biology, The University of Iowa, Iowa City, Iowa, USA
| | - Karla J Daniels
- Developmental Studies Hybridoma Bank, Department of Biology, The University of Iowa, Iowa City, Iowa, USA
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Abstract
Microbial biofilm communities are protected against environmental extremes or clearance by antimicrobial agents or the host immune response. They also serve as a site from which microbial populations search for new niches by dispersion via single planktonic cells or by detachment by protected biofilm aggregates that, until recently, were thought to become single cells ready for attachment. Mathematically modeling these events has provided investigators with testable hypotheses for further study. Such was the case in the recent article by Kragh et al. (K. N. Kragh, J. B. Hutchison, G. Melaugh, C. Rodesney, A. E. Roberts, Y. Irie, P. Ø. Jensen, S. P. Diggle, R. J. Allen, V. Gordon, and T. Bjarnsholt, mBio 7:e00237-16, 2016, http://dx.doi.org/10.1128/mBio.00237-16), in which investigators were able to identify the differential competitive advantage of biofilm aggregates to directly attach to surfaces compared to the single-celled planktonic populations. Therefore, as we delve deeper into the properties of the biofilm mode of growth, not only do we need to understand the complexity of biofilms, but we must also account for the properties of the dispersed and detached populations and their effect on reseeding.
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Kragh KN, Hutchison JB, Melaugh G, Rodesney C, Roberts AEL, Irie Y, Jensen PØ, Diggle SP, Allen RJ, Gordon V, Bjarnsholt T. Role of Multicellular Aggregates in Biofilm Formation. mBio 2016; 7:e00237. [PMID: 27006463 PMCID: PMC4807362 DOI: 10.1128/mbio.00237-16] [Citation(s) in RCA: 199] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 02/22/2016] [Indexed: 11/25/2022] Open
Abstract
UNLABELLED In traditional models ofin vitrobiofilm development, individual bacterial cells seed a surface, multiply, and mature into multicellular, three-dimensional structures. Much research has been devoted to elucidating the mechanisms governing the initial attachment of single cells to surfaces. However, in natural environments and during infection, bacterial cells tend to clump as multicellular aggregates, and biofilms can also slough off aggregates as a part of the dispersal process. This makes it likely that biofilms are often seeded by aggregates and single cells, yet how these aggregates impact biofilm initiation and development is not known. Here we use a combination of experimental and computational approaches to determine the relative fitness of single cells and preformed aggregates during early development ofPseudomonas aeruginosabiofilms. We find that the relative fitness of aggregates depends markedly on the density of surrounding single cells, i.e., the level of competition for growth resources. When competition between aggregates and single cells is low, an aggregate has a growth disadvantage because the aggregate interior has poor access to growth resources. However, if competition is high, aggregates exhibit higher fitness, because extending vertically above the surface gives cells at the top of aggregates better access to growth resources. Other advantages of seeding by aggregates, such as earlier switching to a biofilm-like phenotype and enhanced resilience toward antibiotics and immune response, may add to this ecological benefit. Our findings suggest that current models of biofilm formation should be reconsidered to incorporate the role of aggregates in biofilm initiation. IMPORTANCE During the past decades, there has been a consensus around the model of development of a biofilm, involving attachment of single planktonic bacterial cells to a surface and the subsequent development of a mature biofilm. This study presents results that call for a modification of this rigorous model. We show how free floating biofilm aggregates can have a profound local effect on biofilm development when attaching to a surface. Our findings show that an aggregate landing on a surface will eventually outcompete the biofilm population arising from single cells attached around the aggregate and dominate the local biofilm development. These results point to a regime where preformed biofilm aggregates may have a fitness advantage over planktonic cells when it comes to accessing nutrients. Our findings add to the increasingly prominent comprehension that biofilm lifestyle is the default for bacteria and that planktonic single cells may be only a transition state at the most.
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Affiliation(s)
- Kasper N Kragh
- Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Jaime B Hutchison
- Center for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin, Austin, Texas, USA
| | - Gavin Melaugh
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Chris Rodesney
- Center for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin, Austin, Texas, USA
| | - Aled E L Roberts
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Yasuhiko Irie
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Peter Ø Jensen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Stephen P Diggle
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Rosalind J Allen
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
| | - Vernita Gordon
- Center for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin, Austin, Texas, USA Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Thomas Bjarnsholt
- Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
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Abstract
The dense aggregation of cells on a surface, as seen in biofilms, inevitably results in both environmental and cellular heterogeneity. For example, nutrient gradients can trigger cells to differentiate into various phenotypic states. Not only do cells adapt physiologically to the local environmental conditions, but they also differentiate into cell types that interact with each other. This allows for task differentiation and, hence, the division of labor. In this article, we focus on cell differentiation and the division of labor in three bacterial species: Myxococcus xanthus, Bacillus subtilis, and Pseudomonas aeruginosa. During biofilm formation each of these species differentiates into distinct cell types, in some cases leading to cooperative interactions. The division of labor and the cooperative interactions between cell types are assumed to yield an emergent ecological benefit. Yet in most cases the ecological benefits have yet to be elucidated. A notable exception is M. xanthus, in which cell differentiation within fruiting bodies facilitates the dispersal of spores. We argue that the ecological benefits of the division of labor might best be understood when we consider the dynamic nature of both biofilm formation and degradation.
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Abstract
Bacteria have a natural propensity to grow as sessile, matrix-encapsulated, multicellular communities called biofilms. Formation of biofilms proceeds through genetically programmed, distinct developmental stages signaled by intricate networks of communication among the constituent population and their environment. Growing in the complex and heterogeneous microenvironments of biofilms, the resident bacteria acquire unique phenotypes that are generally not associated with their planktonic counterparts. Most notable among these is an extraordinary level of tolerance to a variety of environmental stresses, including antibiotics. Although mycobacteria have long been observed to spontaneously form complex multicellular structures in vitro, it has only recently become apparent that these structures are not only formed through dedicated genetic pathways but are also tolerant to antibiotics. In this article, we review the recent advances in the understanding of mycobacterial biofilms in vitro. We further consider the possible linkage between biofilm-like lifestyles and characteristic persistence of mycobacterial infections against host-defense mechanisms as well as antibiotics.
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Kim SK, Lee JH. Biofilm dispersion in Pseudomonas aeruginosa. J Microbiol 2016; 54:71-85. [PMID: 26832663 DOI: 10.1007/s12275-016-5528-7] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 12/22/2015] [Accepted: 12/22/2015] [Indexed: 02/07/2023]
Abstract
In recent decades, many researchers have written numerous articles about microbial biofilms. Biofilm is a complex community of microorganisms and an example of bacterial group behavior. Biofilm is usually considered a sessile mode of life derived from the attached growth of microbes to surfaces, and most biofilms are embedded in self-produced extracellular matrix composed of extracellular polymeric substances (EPSs), such as polysaccharides, extracellular DNAs (eDNA), and proteins. Dispersal, a mode of biofilm detachment indicates active mechanisms that cause individual cells to separate from the biofilm and return to planktonic life. Since biofilm cells are cemented and surrounded by EPSs, dispersal is not simple to do and many researchers are now paying more attention to this active detachment process. Unlike other modes of biofilm detachment such as erosion or sloughing, which are generally considered passive processes, dispersal occurs as a result of complex spatial differentiation and molecular events in biofilm cells in response to various environmental cues, and there are many biological reasons that force bacterial cells to disperse from the biofilms. In this review, we mainly focus on the spatial differentiation of biofilm that is a prerequisite for dispersal, as well as environmental cues and molecular events related to the biofilm dispersal. More specifically, we discuss the dispersal-related phenomena and mechanisms observed in Pseudomonas aeruginosa, an important opportunistic human pathogen and representative model organism for biofilm study.
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Affiliation(s)
- Soo-Kyoung Kim
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan, 609-735, Republic of Korea
| | - Joon-Hee Lee
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan, 609-735, Republic of Korea.
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Petrova OE, Sauer K. Escaping the biofilm in more than one way: desorption, detachment or dispersion. Curr Opin Microbiol 2016; 30:67-78. [PMID: 26826978 DOI: 10.1016/j.mib.2016.01.004] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 01/07/2016] [Accepted: 01/08/2016] [Indexed: 12/15/2022]
Abstract
Biofilm bacteria have developed escape strategies to avoid stresses associated with biofilm growth, respond to changing environmental conditions, and disseminate to new locations. An ever-expanding body of research suggests that cellular release from biofilms is distinct from a simple reversal of attachment and reversion to a planktonic mode of growth, with biofilm dispersion involving sensing of specific cues, regulatory signal transduction, and consequent physiological alterations. However, dispersion is only one of many ways to escape the biofilm mode of growth. The present review is aimed at distinguishing this active and regulated process of dispersion from the passive processes of desorption and detachment by highlighting the regulatory processes and distinct phenotypes specific to dispersed cells.
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Affiliation(s)
- Olga E Petrova
- Department of Biological Sciences, Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902, United States
| | - Karin Sauer
- Department of Biological Sciences, Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902, United States.
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Barzegar Amiri Olia M, Zavras A, Schiesser CH, Alexander SA. Blue ‘turn-on’ fluorescent probes for the direct detection of free radicals and nitric oxide in Pseudomonas aeruginosa biofilms. Org Biomol Chem 2016; 14:2272-81. [DOI: 10.1039/c5ob02441b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Novel blue cell-permeable ‘turn-on’ fluorescent probes have been developed to visualize and quantify nitric oxide and free radical formation and reaction within aPseudomonas aeruginosabiofilm.
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Affiliation(s)
- Mina Barzegar Amiri Olia
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology
- Australia
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute
- The University of Melbourne
- Victoria
| | - Athanasios Zavras
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology
- Australia
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute
- The University of Melbourne
- Victoria
| | - Carl H. Schiesser
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology
- Australia
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute
- The University of Melbourne
- Victoria
| | - Stefanie-Ann Alexander
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology
- Australia
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute
- The University of Melbourne
- Victoria
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A Mixed-Culture Biofilm Model with Cross-Diffusion. Bull Math Biol 2015; 77:2086-124. [PMID: 26582360 DOI: 10.1007/s11538-015-0117-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 10/15/2015] [Indexed: 10/22/2022]
Abstract
We propose a deterministic continuum model for mixed-culture biofilms. A crucial aspect is that movement of one species is affected by the presence of the other. This leads to a degenerate cross-diffusion system that generalizes an earlier single-species biofilm model. Two derivations of this new model are given. One, like cellular automata biofilm models, starts from a discrete in space lattice differential equation where the spatial interaction is described by microscopic rules. The other one starts from the same continuous mass balances that are the basis of other deterministic biofilm models, but it gives up a simplifying assumption of these models that has recently been criticized as being too restrictive in terms of ecological structure. We show that both model derivations lead to the same PDE model, if corresponding closure assumptions are introduced. To investigate the role of cross-diffusion, we conduct numerical simulations of three biofilm systems: competition, allelopathy and a mixed system formed by an aerobic and an anaerobic species. In all cases, we find that accounting for cross-diffusion affects local distribution of biomass, but it does not affect overall lumped quantities such as the total amount of biomass in the system.
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Rybtke M, Hultqvist LD, Givskov M, Tolker-Nielsen T. Pseudomonas aeruginosa Biofilm Infections: Community Structure, Antimicrobial Tolerance and Immune Response. J Mol Biol 2015; 427:3628-45. [DOI: 10.1016/j.jmb.2015.08.016] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/18/2015] [Accepted: 08/20/2015] [Indexed: 02/07/2023]
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