1
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Youngblom MA, Smith TM, Murray HJ, Pepperell CS. Adaptation of the Mycobacterium tuberculosis transcriptome to biofilm growth. PLoS Pathog 2024; 20:e1012124. [PMID: 38635841 PMCID: PMC11060545 DOI: 10.1371/journal.ppat.1012124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 04/30/2024] [Accepted: 03/14/2024] [Indexed: 04/20/2024] Open
Abstract
Mycobacterium tuberculosis (M. tb), the causative agent of tuberculosis (TB), is a leading global cause of death from infectious disease. Biofilms are increasingly recognized as a relevant growth form during M. tb infection and may impede treatment by enabling bacterial drug and immune tolerance. M. tb has a complicated regulatory network that has been well-characterized for many relevant disease states, including dormancy and hypoxia. However, despite its importance, our knowledge of the genes and pathways involved in biofilm formation is limited. Here we characterize the biofilm transcriptomes of fully virulent clinical isolates and find that the regulatory systems underlying biofilm growth vary widely between strains and are also distinct from regulatory programs associated with other environmental cues. We used experimental evolution to investigate changes to the transcriptome during adaptation to biofilm growth and found that the application of a uniform selection pressure resulted in loss of strain-to-strain variation in gene expression, resulting in a more uniform biofilm transcriptome. The adaptive trajectories of transcriptomes were shaped by the genetic background of the M. tb population leading to convergence on a sub-lineage specific transcriptome. We identified widespread upregulation of non-coding RNA (ncRNA) as a common feature of the biofilm transcriptome and hypothesize that ncRNA function in genome-wide modulation of gene expression, thereby facilitating rapid regulatory responses to new environments. These results reveal a new facet of the M. tb regulatory system and provide valuable insight into how M. tb adapts to new environments.
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Affiliation(s)
- Madison A. Youngblom
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Madison-Wisconsin, Madison, Wisconsin, United States of America
| | - Tracy M. Smith
- Department of Medicine (Infectious Diseases), School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Holly J. Murray
- Department of Medicine (Infectious Diseases), School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Caitlin S. Pepperell
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Madison-Wisconsin, Madison, Wisconsin, United States of America
- Department of Medicine (Infectious Diseases), School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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2
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Tago H, Maeda Y, Tanaka Y, Kohketsu H, Lim TK, Harada M, Yoshino T, Matsunaga T, Tanaka T. Line image sensor-based colony fingerprinting system for rapid pathogenic bacteria identification. Biosens Bioelectron 2024; 249:116006. [PMID: 38199081 DOI: 10.1016/j.bios.2024.116006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/03/2024] [Accepted: 01/04/2024] [Indexed: 01/12/2024]
Abstract
The rapid identification of pathogenic bacteria is crucial across various industries, including food or beverage manufacturing. Bacterial microcolony image-based classification has emerged as a promising approach to expedite identification, automate inspections, and reduce costs. However, conventional imaging methods have significant practical limitations, namely low throughput caused by the limited imaging range and slow imaging speed. To address these challenges, we developed an imaging system based on a line image sensor for rapid and wide-field imaging compared to existing colony imaging methods. This system can image a standard Petri dish (92 mm in diameter) completely within 22 s, successfully acquiring bacterial microcolony images. This process yielded a set of discrimination parameters termed as colony fingerprints, which were employed for machine learning. We demonstrated the performance of our system by identifying Staphylococcus aureus in food products using a machine learning model trained on a colony fingerprint dataset of 15 species from 9 genera, including foodborne pathogens. While conventional mass spectrometry-based methods require 24 h of incubation, our colony fingerprinting approach achieved 96% accuracy in just 10 h of incubation. Line image sensor offer high imaging speeds and scalability, allowing for swift and straightforward microbiological testing, eliminating the need for specialized expertise and overcoming the limitations of conventional methods. This innovation marks a transformative shift in industrial applications.
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Affiliation(s)
- Hikaru Tago
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Yoshiaki Maeda
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan; Institute of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Yusuke Tanaka
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Hiroya Kohketsu
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Tae-Kyu Lim
- Malcom Co., Ltd., 4-15-10, Honmachi, Shibuya-ku, Tokyo, 151-0071, Japan
| | - Manabu Harada
- Malcom Co., Ltd., 4-15-10, Honmachi, Shibuya-ku, Tokyo, 151-0071, Japan
| | - Tomoko Yoshino
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Tadashi Matsunaga
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Tsuyoshi Tanaka
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan.
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3
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Vohra M, Kour A, Kalia NP, Kumar M, Sharma S, Jaglan S, Kamath N, Sharma S. A comprehensive review of genomics, transcriptomics, proteomics, and metabolomic insights into the differentiation of Pseudomonas aeruginosa from the planktonic to biofilm state: A multi-omics approach. Int J Biol Macromol 2024; 257:128563. [PMID: 38070800 DOI: 10.1016/j.ijbiomac.2023.128563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 11/06/2023] [Accepted: 11/30/2023] [Indexed: 01/26/2024]
Abstract
Biofilm formation by Pseudomonas aeruginosa is primarily responsible for chronic wound and lung infections in humans. These infections are persistent owing to the biofilm's high tolerance to antimicrobials and constantly changing environmental factors. Understanding the mechanism governing biofilm formation can help to develop therapeutics explicitly directed against the molecular markers responsible for this process. After numerous years of research, many genes responsible for both in vitro and in vivo biofilm development remain unidentified. However, there is no "all in one" complete in vivo or in vitro biofilm model. Recent findings imply that the shift from planktonic bacteria to biofilms is a complicated and interrelated differentiation process. Research on the applications of omics technologies in P. aeruginosa biofilm development is ongoing, and these approaches hold great promise for expanding our knowledge of the mechanisms of biofilm formation. This review discusses the different factors that affect biofilm formation and compares P. aeruginosa biofilm formation using the omics approaches targeting essential biological macromolecules, such as DNA, RNA, Protein, and metabolome. Furthermore, we have outlined the application of currently available omics tools, such as genomics, proteomics, metabolomics, transcriptomics, and integrated multi-omics methodologies, to understand the differential gene expression (biofilm vs. planktonic bacteria) of P. aeruginosa biofilms.
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Affiliation(s)
- Mustafa Vohra
- Department of Medical Laboratory Science, Lovely Professional University, Punjab 144411, India; Department of Microbiology, Shri Vinoba Bhave Civil Hospital, Silvassa 396230, India
| | - Avleen Kour
- Department of Medical Laboratory Science, Lovely Professional University, Punjab 144411, India
| | - Nitin Pal Kalia
- Department of Biological Sciences (Pharmacology & Toxicology), National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, Telangana 500037, India
| | - Manoj Kumar
- Maternal and Child Health Program, Research Department, Sidra Medicine, Doha 122104, Qatar
| | - Sarika Sharma
- Department of Sponsored Research, Division of Research & Development, Lovely Professional University, India
| | - Sundeep Jaglan
- Fermentation & Microbial Biotechnology Division, CSIR-Indian Institute of Integrative Medicine, Jammu 180016, J&K, India
| | - Narayan Kamath
- Department of Microbiology, Shri Vinoba Bhave Civil Hospital, Silvassa 396230, India; Department of Microbiology, NAMO Medical Education and Research Institute, Silvassa 396230, India
| | - Sandeep Sharma
- Department of Medical Laboratory Science, Lovely Professional University, Punjab 144411, India.
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4
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Mendoza AG, Guercio D, Smiley MK, Sharma GK, Withorn JM, Hudson-Smith NV, Ndukwe C, Dietrich LEP, Boon EM. The histidine kinase NahK regulates pyocyanin production through the PQS system. J Bacteriol 2024; 206:e0027623. [PMID: 38169296 PMCID: PMC10809955 DOI: 10.1128/jb.00276-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/12/2023] [Indexed: 01/05/2024] Open
Abstract
Many bacterial histidine kinases work in two-component systems that combine into larger multi-kinase networks. NahK is one of the kinases in the GacS Multi-Kinase Network (MKN), which is the MKN that controls biofilm regulation in the opportunistic pathogen Pseudomonas aeruginosa. This network has also been associated with regulating many virulence factors P. aeruginosa secretes to cause disease. However, the individual role of each kinase is unknown. In this study, we identify NahK as a novel regulator of the phenazine pyocyanin (PYO). Deletion of nahK leads to a fourfold increase in PYO production, almost exclusively through upregulation of phenazine operon two (phz2). We determined that this upregulation is due to mis-regulation of all P. aeruginosa quorum-sensing (QS) systems, with a large upregulation of the Pseudomonas quinolone signal system and a decrease in production of the acyl-homoserine lactone-producing system, las. In addition, we see differences in expression of quorum-sensing inhibitor proteins that align with these changes. Together, these data contribute to understanding how the GacS MKN modulates QS and virulence and suggest a mechanism for cell density-independent regulation of quorum sensing. IMPORTANCE Pseudomonas aeruginosa is a Gram-negative bacterium that establishes biofilms as part of its pathogenicity. P. aeruginosa infections are associated with nosocomial infections. As the prevalence of multi-drug-resistant P. aeruginosa increases, it is essential to understand underlying virulence molecular mechanisms. Histidine kinase NahK is one of several kinases in P. aeruginosa implicated in biofilm formation and dispersal. Previous work has shown that the nitric oxide sensor, NosP, triggers biofilm dispersal by inhibiting NahK. The data presented here demonstrate that NahK plays additional important roles in the P. aeruginosa lifestyle, including regulating bacterial communication mechanisms such as quorum sensing. These effects have larger implications in infection as they affect toxin production and virulence.
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Affiliation(s)
- Alicia G. Mendoza
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Danielle Guercio
- Department of Molecular and Cellular Biology, Stony Brook University, Stony Brook, New York, USA
| | - Marina K. Smiley
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Gaurav K. Sharma
- Department of Chemistry, Stony Brook University, Stony Brook, New York, USA
| | - Jason M. Withorn
- Department of Chemistry, Stony Brook University, Stony Brook, New York, USA
| | | | - Chika Ndukwe
- Department of Chemistry, Stony Brook University, Stony Brook, New York, USA
| | - Lars E. P. Dietrich
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Elizabeth M. Boon
- Department of Chemistry, Stony Brook University, Stony Brook, New York, USA
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5
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Nazeer RR, Wang M, Welch M. More than just a gel: the extracellular matrixome of Pseudomonas aeruginosa. Front Mol Biosci 2023; 10:1307857. [PMID: 38028553 PMCID: PMC10679415 DOI: 10.3389/fmolb.2023.1307857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 10/31/2023] [Indexed: 12/01/2023] Open
Abstract
Armed with an arsenal of protein secretion systems, antibiotic efflux pumps, and the occasional proclivity for explosive self-destruction, Pseudomonas aeruginosa has become a model for the study of bacterial pathogenesis and biofilm formation. There is accruing evidence to suggest that the biofilm matrix-the bioglue that holds the structure together-acts not only in a structural capacity, but is also a molecular "net" whose function is to capture and retain certain secreted products (including proteins and small molecules). In this perspective, we argue that the biofilm matrixome is a distinct extracellular compartment, and one that is differentiated from the bulk secretome. Some of the points we raise are deliberately speculative, but are becoming increasingly accessible to experimental investigation.
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Affiliation(s)
| | | | - Martin Welch
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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6
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Di Trani JM, Gheorghita AA, Turner M, Brzezinski P, Ädelroth P, Vahidi S, Howell PL, Rubinstein JL. Structure of the bc1- cbb3 respiratory supercomplex from Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 2023; 120:e2307093120. [PMID: 37751552 PMCID: PMC10556555 DOI: 10.1073/pnas.2307093120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 08/14/2023] [Indexed: 09/28/2023] Open
Abstract
Energy conversion by electron transport chains occurs through the sequential transfer of electrons between protein complexes and intermediate electron carriers, creating the proton motive force that enables ATP synthesis and membrane transport. These protein complexes can also form higher order assemblies known as respiratory supercomplexes (SCs). The electron transport chain of the opportunistic pathogen Pseudomonas aeruginosa is closely linked with its ability to invade host tissue, tolerate harsh conditions, and resist antibiotics but is poorly characterized. Here, we determine the structure of a P. aeruginosa SC that forms between the quinol:cytochrome c oxidoreductase (cytochrome bc1) and one of the organism's terminal oxidases, cytochrome cbb3, which is found only in some bacteria. Remarkably, the SC structure also includes two intermediate electron carriers: a diheme cytochrome c4 and a single heme cytochrome c5. Together, these proteins allow electron transfer from ubiquinol in cytochrome bc1 to oxygen in cytochrome cbb3. We also present evidence that different isoforms of cytochrome cbb3 can participate in formation of this SC without changing the overall SC architecture. Incorporating these different subunit isoforms into the SC would allow the bacterium to adapt to different environmental conditions. Bioinformatic analysis focusing on structural motifs in the SC suggests that cytochrome bc1-cbb3 SCs also exist in other bacterial pathogens.
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Affiliation(s)
- Justin M. Di Trani
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
| | - Andreea A. Gheorghita
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ONM5S 1A8, Canada
| | - Madison Turner
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ONN1G 2W1, Canada
| | - Peter Brzezinski
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, StockholmSE-106 91, Sweden
| | - Pia Ädelroth
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, StockholmSE-106 91, Sweden
| | - Siavash Vahidi
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ONN1G 2W1, Canada
| | - P. Lynne Howell
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ONM5S 1A8, Canada
| | - John L. Rubinstein
- Molecular Medicine program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ONM5S 1A8, Canada
- Department of Medical Biophysics, The University of Toronto, Toronto, ONM5G 1L7, Canada
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7
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Lichtenberg M, Coenye T, Parsek MR, Bjarnsholt T, Jakobsen TH. What's in a name? Characteristics of clinical biofilms. FEMS Microbiol Rev 2023; 47:fuad050. [PMID: 37656883 PMCID: PMC10503651 DOI: 10.1093/femsre/fuad050] [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: 06/10/2023] [Revised: 08/06/2023] [Accepted: 08/30/2023] [Indexed: 09/03/2023] Open
Abstract
In vitro biofilms are communities of microbes with unique features compared to individual cells. Biofilms are commonly characterized by physical traits like size, adhesion, and a matrix made of extracellular substances. They display distinct phenotypic features, such as metabolic activity and antibiotic tolerance. However, the relative importance of these traits depends on the environment and bacterial species. Various mechanisms enable biofilm-associated bacteria to withstand antibiotics, including physical barriers, physiological adaptations, and changes in gene expression. Gene expression profiles in biofilms differ from individual cells but, there is little consensus among studies and so far, a 'biofilm signature transcriptome' has not been recognized. Additionally, the spatial and temporal variability within biofilms varies greatly depending on the system or environment. Despite all these variable conditions, which produce very diverse structures, they are all noted as biofilms. We discuss that clinical biofilms may differ from those grown in laboratories and found in the environment and discuss whether the characteristics that are commonly used to define and characterize biofilms have been shown in infectious biofilms. We emphasize that there is a need for a comprehensive understanding of the specific traits that are used to define bacteria in infections as clinical biofilms.
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Affiliation(s)
- Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Matthew R Parsek
- Department of Microbiology, University of Washington School of Medicine, 1705 NE Pacific St., WA 98195 Seattle, United States
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Department of Clinical Microbiology, Copenhagen University Hospital, Ole Maaløes vej 26, 2100 Copenhagen, Denmark
| | - Tim Holm Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
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8
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Zina R, Cunha E, Serrano I, Silva E, Tavares L, Oliveira M. Nisin Z Potential for the Control of Diabetic Foot Infections Promoted by Pseudomonas aeruginosa Persisters. Antibiotics (Basel) 2023; 12:antibiotics12050794. [PMID: 37237697 DOI: 10.3390/antibiotics12050794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023] Open
Abstract
Diabetic foot ulcers (DFU) are a major complication of diabetes mellitus and a public health concern worldwide. The ability of P. aeruginosa to form biofilms is a key factor responsible for the chronicity of diabetic foot infections (DFIs) and frequently associated with the presence of persister cells. These are a subpopulation of phenotypic variants highly tolerant to antibiotics for which new therapeutic alternatives are urgently needed, such as those based on antimicrobial peptides. This study aimed to evaluate the inhibitory effect of nisin Z on P. aeruginosa DFI persisters. To induce the development of a persister state in both planktonic suspensions and biofilms, P. aeruginosa DFI isolates were exposed to carbonyl cyanide m-chlorophenylhydrazone (CCCP) and ciprofloxacin, respectively. After RNA extraction from CCCP-induced persisters, transcriptome analysis was performed to evaluate the differential gene expression between the control, persisters, and persister cells exposed to nisin Z. Nisin Z presented a high inhibitory effect against P. aeruginosa persister cells but was unable to eradicate them when present in established biofilms. Transcriptome analysis revealed that persistence was associated with downregulation of genes related to metabolic processes, cell wall synthesis, and dysregulation of stress response and biofilm formation. After nisin Z treatment, some of the transcriptomic changes induced by persistence were reversed. In conclusion, nisin Z could be considered as a potential complementary therapy for treating P. aeruginosa DFI, but it should be applied as an early treatment or after wound debridement.
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Affiliation(s)
- Rafaela Zina
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
| | - Eva Cunha
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
| | - Isa Serrano
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
| | - Elisabete Silva
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
| | - Luís Tavares
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
| | - Manuela Oliveira
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
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9
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Mohamad F, Alzahrani RR, Alsaadi A, Alrfaei BM, Yassin AEB, Alkhulaifi MM, Halwani M. An Explorative Review on Advanced Approaches to Overcome Bacterial Resistance by Curbing Bacterial Biofilm Formation. Infect Drug Resist 2023; 16:19-49. [PMID: 36636380 PMCID: PMC9830422 DOI: 10.2147/idr.s380883] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 12/06/2022] [Indexed: 01/05/2023] Open
Abstract
The continuous emergence of multidrug-resistant pathogens evoked the development of innovative approaches targeting virulence factors unique to their pathogenic cascade. These approaches aimed to explore anti-virulence or anti-infective therapies. There are evident concerns regarding the bacterial ability to create a superstructure, the biofilm. Biofilm formation is a crucial virulence factor causing difficult-to-treat, localized, and systemic infections. The microenvironments of bacterial biofilm reduce the efficacy of antibiotics and evade the host's immunity. Producing a biofilm is not limited to a specific group of bacteria; however, Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus biofilms are exemplary models. This review discusses biofilm formation as a virulence factor and the link to antimicrobial resistance. In addition, it explores insights into innovative multi-targeted approaches and their physiological mechanisms to combat biofilms, including natural compounds, phages, antimicrobial photodynamic therapy (aPDT), CRISPR-Cas gene editing, and nano-mediated techniques.
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Affiliation(s)
- F Mohamad
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Raghad R Alzahrani
- Nanomedicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia,Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Ahlam Alsaadi
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Bahauddeen M Alrfaei
- Stem Cells and Regenerative Medicine, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Alaa Eldeen B Yassin
- College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
| | - Manal M Alkhulaifi
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia,Manal M Alkhulaifi, P.O. Box 55670, Riyadh, 11544, Tel +966 (11) 805-1685, Email
| | - Majed Halwani
- Nanomedicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia,Correspondence: Majed Halwani, P.O. Box 3660, Mail Code 1515 (KAIMRC), Riyadh, 11481, Tel +966 (11) 429-4433, Fax +966 (11) 429-4440, Email ;
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10
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Biofilm antimicrobial susceptibility through an experimental evolutionary lens. NPJ Biofilms Microbiomes 2022; 8:82. [PMID: 36257971 PMCID: PMC9579162 DOI: 10.1038/s41522-022-00346-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 10/04/2022] [Indexed: 11/19/2022] Open
Abstract
Experimental evolution experiments in which bacterial populations are repeatedly exposed to an antimicrobial treatment, and examination of the genotype and phenotype of the resulting evolved bacteria, can help shed light on mechanisms behind reduced susceptibility. In this review we present an overview of why it is important to include biofilms in experimental evolution, which approaches are available to study experimental evolution in biofilms and what experimental evolution has taught us about tolerance and resistance in biofilms. Finally, we present an emerging consensus view on biofilm antimicrobial susceptibility supported by data obtained during experimental evolution studies.
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11
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Valzano F, Boncompagni SR, Micieli M, Di Maggio T, Di Pilato V, Colombini L, Santoro F, Pozzi G, Rossolini GM, Pallecchi L. Activity of N-Acetylcysteine Alone and in Combination with Colistin against Pseudomonas aeruginosa Biofilms and Transcriptomic Response to N-Acetylcysteine Exposure. Microbiol Spectr 2022; 10:e0100622. [PMID: 35735984 PMCID: PMC9431628 DOI: 10.1128/spectrum.01006-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/03/2022] [Indexed: 11/25/2022] Open
Abstract
Chronic colonization by Pseudomonas aeruginosa is critical in cystic fibrosis (CF) and other chronic lung diseases, contributing to disease progression. Biofilm growth and a propensity to evolve multidrug resistance phenotypes drastically limit the available therapeutic options. In this perspective, there has been growing interest in evaluating combination therapies, especially for drugs that can be administered by nebulization, which allows high drug concentrations to be reached at the site of infections while limiting systemic toxicity. Here, we investigated the potential antibiofilm activity of N-acetylcysteine (NAC) alone and in combination with colistin against a panel of P. aeruginosa strains (most of which are from CF patients) and the transcriptomic response of a P. aeruginosa CF strain to NAC exposure. NAC alone (8,000 mg/L) showed a limited and strain-dependent antibiofilm activity. Nonetheless, a relevant antibiofilm synergism of NAC-colistin combinations (NAC at 8,000 mg/L plus colistin at 2 to 32 mg/L) was observed with all strains. Synergism was also confirmed with the artificial sputum medium model. RNA sequencing of NAC-exposed planktonic cultures revealed that NAC (8,000 mg/L) mainly induced (i) a Zn2+ starvation response (known to induce attenuation of P. aeruginosa virulence), (ii) downregulation of genes of the denitrification apparatus, and (iii) downregulation of flagellar biosynthesis pathway. NAC-mediated inhibition of P. aeruginosa denitrification pathway and flagellum-mediated motility were confirmed experimentally. These findings suggested that NAC-colistin combinations might contribute to the management of biofilm-associated P. aeruginosa lung infections. NAC might also have a role in reducing P. aeruginosa virulence, which could be relevant in the very early stages of lung colonization. IMPORTANCE Pseudomonas aeruginosa biofilm-related chronic lung colonization contributes to cystic fibrosis (CF) disease progression. Colistin is often a last-resort antibiotic for the treatment of such P. aeruginosa infections, and it has been increasingly used in CF, especially by nebulization. N-acetylcysteine (NAC) is a mucolytic agent with antioxidant activity, commonly administered with antibiotics for the treatment of lower respiratory tract infections. Here, we show that NAC potentiated colistin activity against in vitro biofilms models of P. aeruginosa strains, with both drugs tested at the high concentrations achievable after nebulization. In addition, we report the first transcriptomic data on the P. aeruginosa response to NAC exposure.
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Affiliation(s)
- Felice Valzano
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | | | - Maria Micieli
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Tiziana Di Maggio
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Vincenzo Di Pilato
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy
| | - Lorenzo Colombini
- Laboratory of Molecular Microbiology and Biotechnology, Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Francesco Santoro
- Laboratory of Molecular Microbiology and Biotechnology, Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Gianni Pozzi
- Laboratory of Molecular Microbiology and Biotechnology, Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Gian Maria Rossolini
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
- Clinical Microbiology and Virology Unit, Careggi University Hospital, Florence, Italy
| | - Lucia Pallecchi
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
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12
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Díaz-Pérez SP, Solis CS, López-Bucio JS, Valdez Alarcón JJ, Villegas J, Reyes-De la Cruz H, Campos-Garcia J. Pathogenesis in Pseudomonas aeruginosa PAO1 Biofilm-Associated Is Dependent on the Pyoverdine and Pyocyanin Siderophores by Quorum Sensing Modulation. MICROBIAL ECOLOGY 2022:10.1007/s00248-022-02095-5. [PMID: 35948833 DOI: 10.1007/s00248-022-02095-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogenic bacterium for humans, animals, and plants, through producing different molecular factors such as biofilm, siderophores, and other virulence factors which favor bacterial establishment and infection in the host. In P. aeruginosa PAO1, the production of these factors is regulated by the bacterial quorum sensing (QS) mechanisms. From them, siderophores are involved in iron acquisition, transport, and homeostasis. They are also considered some of the main virulence factors in P. aeruginosa; however, detailed mechanisms to induce bacterial pathogenesis are poorly understood. In this work, through reverse genetics, we evaluated the function of bacterial pathogenesis in the pvd cluster genes, which are required for synthesizing the siderophore pyoverdine (PVD). Single pvdI, pvdJ, pvdL, and double mutant strains were analyzed, and contrary to expected, the pvdL and pvdI mutations increased the concentration of PVD and other phenazines, such as pyocyanin (PYO) and phenazine-1-carboxylic acid (PCA) and also an increased biofilm production and morphology depending on the autoinducer 2-alkyl-4-quinolone (PQS) and the QS molecules acyl-homoserine lactones. Consequently, in the in vivo pathogenicity model of Caenorhabditis elegans, the mutations in pvdI, pvdJ, and pvdL increased the survival of the worms exposed to supernatants or biofilms of the bacterial cultures. However, the double mutant pvdI/pvdJ increased its toxicity in agreeing with the biofilm production, PVD, PYO, and PCA. The findings indicate that the mutations in pvd genes encode non-ribosomal peptide synthetases impacted the biofilm's structure, but suppressively also of the phenazines, confirming that the siderophores contribute to the bacterial establishment and pathogenicity of P. aeruginosa PAO1.
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Affiliation(s)
- Sharel Pamela Díaz-Pérez
- Laboratorio de Biotecnología Microbiana, Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edif. U-3, Ciudad Universitaria, CP. 58030, Morelia, Michoacán, México
| | - Christian Said Solis
- Laboratorio de Biotecnología Microbiana, Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edif. U-3, Ciudad Universitaria, CP. 58030, Morelia, Michoacán, México
| | - Jesús Salvador López-Bucio
- Laboratorio de Control Traduccional, Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Juan J Valdez Alarcón
- Centro de Estudios Multidisciplinarios en Biotecnología, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán, México
| | - Javier Villegas
- Laboratorio de Interacción Suelo, Planta, Microorganismo, Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Homero Reyes-De la Cruz
- Laboratorio de Control Traduccional, Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Jesús Campos-Garcia
- Laboratorio de Biotecnología Microbiana, Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edif. U-3, Ciudad Universitaria, CP. 58030, Morelia, Michoacán, México.
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13
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Al-Zawity J, Afzal F, Awan A, Nordhoff D, Kleimann A, Wesner D, Montier T, Le Gall T, Müller M. Effects of the Sex Steroid Hormone Estradiol on Biofilm Growth of Cystic Fibrosis Pseudomonas aeruginosa Isolates. Front Cell Infect Microbiol 2022; 12:941014. [PMID: 35909974 PMCID: PMC9326073 DOI: 10.3389/fcimb.2022.941014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/08/2022] [Indexed: 11/23/2022] Open
Abstract
Women with cystic fibrosis (CF) have a significantly lower life expectancy compared to men, which is indicated by an earlier impairment of lung function due to chronic colonization with biofilm formed by Pseudomonas aeruginosa. There is growing evidence that blood serum concentrations of the steroid sex hormone estradiol (E2) correlate with the occurrence of pulmonary exacerbations in CF but also play a role in the mucoid switch of P. aeruginosa. This study aims to shed light on possible microbiological reasons for sexual dimorphism in CF by investigating the influence of E2 on biofilm formation of P. aeruginosa CF isolates. For this purpose, 10 CF isolates of the respiratory tract derived from different CF patients have been treated with E2 in a microtiter plate biofilm model. Biofilms have been examined by crystal violet assays, field emission scanning electron microscopy (FE-SEM), 3D laser scanning microscopy (LSM), and quorum sensing (QS) reporter assays of the supernatants taken from biofilms. This allowed us to simultaneously investigate the effects of E2 on attached biofilm mass, biofilm ultrastructure, and QS activity. Upon E2 treatment, six out of 10 investigated CF isolates showed an increase of attached biofilm mass, whereas biofilms from two tested non-CF laboratory strains (PAO1 and ATCC19660) did not. Moreover, FE-SEM and 3D LSM analyses of the E2 responsive CF biofilms revealed ultrastructural remodeling of biofilm structure at different scales with increased formation of prominent biofilm spots, enhanced coverage with extracellular polymeric substance (EPS), and extended average surface roughness. QS activity measurements performed in biofilm supernatants via luminescence acyl homoserine lactone (AHL) reporter assays further showed that E2 treatment may also modulate QS signaling, as shown in an E2 sensitive CF isolate. Together, our results suggest the biofilm modulating effects of E2 on various clinical CF isolates that are documented by both biomass and ultrastructural changes of biofilms. The gained new insight into the influence of steroid hormones on P. aeruginosa biofilm phenotypes might pave the way for novel future approaches in personalized medicine based on the patients’ sex and hormonal status.
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Affiliation(s)
- Jiwar Al-Zawity
- Physical Chemistry I and Research Center of Micro- and Nanochemistry and (Bio)Technology (Cμ), Department of Chemistry and Biology, University of Siegen, Siegen, Germany
| | - Faria Afzal
- Physical Chemistry I and Research Center of Micro- and Nanochemistry and (Bio)Technology (Cμ), Department of Chemistry and Biology, University of Siegen, Siegen, Germany
| | - Aysha Awan
- Physical Chemistry I and Research Center of Micro- and Nanochemistry and (Bio)Technology (Cμ), Department of Chemistry and Biology, University of Siegen, Siegen, Germany
| | - Daniela Nordhoff
- Physical Chemistry I and Research Center of Micro- and Nanochemistry and (Bio)Technology (Cμ), Department of Chemistry and Biology, University of Siegen, Siegen, Germany
| | - Alexander Kleimann
- Physical Chemistry I and Research Center of Micro- and Nanochemistry and (Bio)Technology (Cμ), Department of Chemistry and Biology, University of Siegen, Siegen, Germany
| | - Daniel Wesner
- Physical Chemistry I and Research Center of Micro- and Nanochemistry and (Bio)Technology (Cμ), Department of Chemistry and Biology, University of Siegen, Siegen, Germany
| | - Tristan Montier
- INSERM, Univ Brest, EFS, UMR 1078, GGB-GTCA, Brest, France
- CHRU de Brest, Service de Génétique Médicale et de Biologie de la Reproduction, Centre de Référence des Maladies Rares “Maladies Neuromusculaires”, Brest, France
| | - Tony Le Gall
- INSERM, Univ Brest, EFS, UMR 1078, GGB-GTCA, Brest, France
| | - Mareike Müller
- Physical Chemistry I and Research Center of Micro- and Nanochemistry and (Bio)Technology (Cμ), Department of Chemistry and Biology, University of Siegen, Siegen, Germany
- *Correspondence: Mareike Müller,
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14
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A previously uncharacterized gene, PA2146, contributes to biofilm formation and drug tolerance across the ɣ-Proteobacteria. NPJ Biofilms Microbiomes 2022; 8:54. [PMID: 35798749 PMCID: PMC9262955 DOI: 10.1038/s41522-022-00314-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 06/14/2022] [Indexed: 01/11/2023] Open
Abstract
Transcriptomic studies have revealed a large number of uncharacterized genes that are differentially expressed in biofilms, which may be important in regulating biofilm phenotypes such as resistance to antimicrobial agents. To identify biofilm genes of unknown function in P. aeruginosa, we made use of RNA-seq and selected 27 uncharacterized genes that were induced upon biofilm growth. Biofilms by respective mutants were subsequently analyzed for two biofilm characteristics, the biofilm architecture and drug susceptibility. The screen revealed 12 out of 27 genes to contribute to biofilm formation and 13 drug susceptibility, with 8 genes affecting both biofilm phenotypes. Amongst the genes affecting both biofilm phenotypes was PA2146, encoding a small hypothetical protein that exhibited some of the most substantial increases in transcript abundance during biofilm growth by P. aeruginosa PAO1 and clinical isolates. PA2146 is highly conserved in ɣ-proteobacteria. Inactivation of PA2146 affected both biofilm phenotypes in P. aeruginosa PAO1, with inactivation of homologs in Klebsiella pneumoniae and Escherichia coli having similar effects. Heterologous expression of PA2146 homologs complemented the P. aeruginosa ∆PA2146, suggesting that PA2146 homologs substitute for and play a similar role as PA2146 in P. aeruginosa.
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15
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Thöming JG, Häussler S. Pseudomonas aeruginosa Is More Tolerant Under Biofilm Than Under Planktonic Growth Conditions: A Multi-Isolate Survey. Front Cell Infect Microbiol 2022; 12:851784. [PMID: 35295755 PMCID: PMC8920030 DOI: 10.3389/fcimb.2022.851784] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 01/24/2022] [Indexed: 01/14/2023] Open
Abstract
Biofilm-associated bacteria exhibit profound changes in bacterial physiology. They thrive in the environment but also in the human host in protected sessile communities. Antimicrobial therapy usually fails, despite the absence of genotypic resistance, and it is commonly accepted that biofilm-grown bacteria are up to 1,000-fold more resistant than planktonic cells. We are only at the beginning to understand the reasons for biofilm recalcitrance, and systematic approaches to describe biofilm-induced tolerance phenotypes are lacking. In this study, we investigated a large and highly diverse collection of 352 clinical Pseudomonas aeruginosa isolates for their antimicrobial susceptibility profiles under biofilm growth conditions towards the antibiotics ciprofloxacin, tobramycin, and colistin. We discovered characteristic patterns of drug-specific killing activity and detected conditional tolerance levels far lower (in the range of the minimal inhibitory concentration (MIC)), but also far higher (up to 16,000-fold increase compared to planktonic cells) than generally believed. This extremely broad distribution of biofilm-induced tolerance phenotypes across the clinical isolates was greatly influenced by the choice of the antibiotic. We furthermore describe cross-tolerance against ciprofloxacin and tobramycin, but not colistin, and observed an additive activity between biofilm-induced tolerance and genetically determined resistance. This became less evident when the biofilm-grown cells were exposed to very high antibiotic concentrations. Although much more remains to be learned on the molecular mechanisms underlying biofilm-induced tolerance, our data on intra-species variations in tolerance profiles provide valuable new insights. Furthermore, our observation that colistin appears to act independently of the tolerance mechanisms of individual clinical strains could make colistin a valuable therapeutic option in chronic biofilm-associated infections characterized by the presence of particularly tolerant strains.
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Affiliation(s)
- Janne G. Thöming
- Department of Clinical Microbiology, University Hospital Copenhagen, Rigshospitalet, Copenhagen, Denmark
- Molecular Bacteriology, Twincore Center for Experimental and Clinical Infection Research GmbH, Hannover, Germany
| | - Susanne Häussler
- Department of Clinical Microbiology, University Hospital Copenhagen, Rigshospitalet, Copenhagen, Denmark
- Molecular Bacteriology, Twincore Center for Experimental and Clinical Infection Research GmbH, Hannover, Germany
- Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
- *Correspondence: Susanne Häussler,
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16
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Jeske A, Arce-Rodriguez A, Thöming JG, Tomasch J, Häussler S. Evolution of biofilm-adapted gene expression profiles in lasR-deficient clinical Pseudomonas aeruginosa isolates. NPJ Biofilms Microbiomes 2022; 8:6. [PMID: 35165270 PMCID: PMC8844440 DOI: 10.1038/s41522-022-00268-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 01/05/2022] [Indexed: 12/13/2022] Open
Abstract
The overall success of a pathogenic microbe depends on its ability to efficiently adapt to challenging conditions in the human host. Long-term evolution experiments track and predict adaptive trajectories and have contributed significantly to our understanding of the driving forces of bacterial adaptation. In this study, we conducted a cross-sectional study instead of long-term longitudinal evolution experiments. We analyzed the transcriptional profiles as well as genomic sequence variations of a large number of clinical Pseudomonas aeruginosa isolates that have been recovered from different infected human sites. Convergent changes in gene expression patterns were found in different groups of clinical isolates. The majority of repeatedly observed expression patterns could be attributed to a defective lasR gene, which encodes the major quorum-sensing regulator LasR. Strikingly, the gene expression pattern of the lasR-defective strains appeared to reflect a transcriptional response that evolves in a direction consistent with growth within a biofilm. In a process of genetic assimilation, lasR-deficient P. aeruginosa isolates appear to constitutively express a biofilm-adapted transcriptional profile and no longer require a respective environmental trigger. Our results demonstrate that profiling the functional consequences of pathoadaptive mutations in clinical isolates reveals long-term evolutionary pathways and may explain the success of lasR mutants in the opportunistic pathogen P. aeruginosa in a clinical context.
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Affiliation(s)
- Alexander Jeske
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany
- Institute for Molecular Bacteriology, TWINCORE, Centre for Experimental and Clinical Infection Research, 30265, Hannover, Germany
| | - Alejandro Arce-Rodriguez
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany
- Institute for Molecular Bacteriology, TWINCORE, Centre for Experimental and Clinical Infection Research, 30265, Hannover, Germany
| | - Janne G Thöming
- Institute for Molecular Bacteriology, TWINCORE, Centre for Experimental and Clinical Infection Research, 30265, Hannover, Germany
- Department of Clinical Microbiology, Copenhagen University Hospital-Rigshospitalet, 2100, Copenhagen, Denmark
| | - Jürgen Tomasch
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany
| | - Susanne Häussler
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, 38124, Braunschweig, Germany.
- Institute for Molecular Bacteriology, TWINCORE, Centre for Experimental and Clinical Infection Research, 30265, Hannover, Germany.
- Department of Clinical Microbiology, Copenhagen University Hospital-Rigshospitalet, 2100, Copenhagen, Denmark.
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, 30265, Hannover, Germany.
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17
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Subroto E, van Neer J, Valdes I, de Cock H. Growth of Aspergillus fumigatus in Biofilms in Comparison to Candida albicans. J Fungi (Basel) 2022; 8:48. [PMID: 35049988 PMCID: PMC8779434 DOI: 10.3390/jof8010048] [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: 12/10/2021] [Revised: 12/29/2021] [Accepted: 12/31/2021] [Indexed: 12/18/2022] Open
Abstract
Biofilm formation during infections with the opportunistic pathogen Aspergillus fumigatus can be very problematic in clinical settings, since it provides the fungal cells with a protective environment. Resistance against drug treatments, immune recognition as well as adaptation to the host environment allows fungal survival in the host. The exact molecular mechanisms behind most processes in the formation of biofilms are unclear. In general, the formation of biofilms can be categorized roughly in a few stages; adhesion, conidial germination and development of hyphae, biofilm maturation and cell dispersion. Fungi in biofilms can adapt to the in-host environment. These adaptations can occur on a level of phenotypic plasticity via gene regulation. However, also more substantial genetic changes of the genome can result in increased resistance and adaptation in the host, enhancing the survival chances of fungi in biofilms. Most research has focused on the development of biofilms. However, to tackle developing microbial resistance and adaptation in biofilms, more insight in mechanisms behind genetic adaptations is required to predict which defense mechanisms can be expected. This can be helpful in the development of novel and more targeted antifungal treatments to combat fungal infections.
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Affiliation(s)
| | | | | | - Hans de Cock
- Molecular Microbiology Laboratory, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; (E.S.); (J.v.N.); (I.V.)
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18
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Transcriptional Profiling of Pseudomonas aeruginosa Infections. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:303-323. [DOI: 10.1007/978-3-031-08491-1_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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19
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D'Arpa P, Karna SLR, Chen T, Leung KP. Pseudomonas aeruginosa transcriptome adaptations from colonization to biofilm infection of skin wounds. Sci Rep 2021; 11:20632. [PMID: 34667187 PMCID: PMC8526614 DOI: 10.1038/s41598-021-00073-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 09/07/2021] [Indexed: 11/09/2022] Open
Abstract
In burn patients Pseudomonas aeruginosa infection is a major cause of morbidity. Analysis of the pathogen's gene expression as it transitions from colonization to acute and then biofilm wound infection may provide strategies for infection control. Toward this goal, we seeded log-phase P. aeruginosa (PAO1) into 3-day-old, full-thickness excision wounds (rabbit ear) and harvested the bacteria during colonization (Hrs 2 and 6), acute infection (Hr 24), and biofilm infection (Days 5 and 9) for transcriptome analysis (RNA-Seq). After 2-6 h in the wound, genes for metabolism and cell replication were down-regulated while wound-adaptation genes were up-regulated (vs. expression in log-phase culture). As the infection progressed from acute to biofilm infection, more genes became up-regulated than down-regulated, but the down-regulated genes enriched in more pathways, likely because the genes and pathways that bacteria already colonizing wounds up-regulate to establish biofilm infection are less known. Across the stages of infection, carbon-utilization pathways shifted. During acute infection, itaconate produced by myeloid cells appears to have been a carbon source because myeloid cell infiltration and the expression of the host gene, ACOD1, for itaconate production peaked coincidently with the expression of the PAO1 genes for itaconate transport and catabolism. Additionally, branched-chain amino acids are suggested to be a carbon source in acute infection and in biofilm infection. In biofilm infection, fatty acid degradation was also up-regulated. These carbon sources feed into the glyoxylate cycle that was coincidently up-regulated, suggesting it provided the precursors for P. aeruginosa to synthesize macromolecules in establishing wound infection.
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Affiliation(s)
- Peter D'Arpa
- Combat Wound Repair Group and Tissue Regeneration Department, US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX, USA.,The Geneva Foundation, Tacoma, USA
| | - S L Rajasekhar Karna
- Combat Wound Repair Group and Tissue Regeneration Department, US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX, USA
| | - Tsute Chen
- The Forsyth Institute, Cambridge, MA, USA
| | - Kai P Leung
- Combat Wound Repair Group and Tissue Regeneration Department, US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX, USA.
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20
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Alonso VPP, de Oliveira Morais J, Kabuki DY. Incidence of Bacillus cereus, Bacillus sporothermodurans and Geobacillus stearothermophilus in ultra-high temperature milk and biofilm formation capacity of isolates. Int J Food Microbiol 2021; 354:109318. [PMID: 34246014 DOI: 10.1016/j.ijfoodmicro.2021.109318] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 06/02/2021] [Accepted: 06/19/2021] [Indexed: 12/19/2022]
Abstract
The presence of mesophilic and thermophilic spore-forming bacteria in UHT milk, as well as biofilm formation in dairy plants, are concerning. The current study explored the spore-forming bacilli diversity in 100 samples of UHT milk (skimmed and whole). Through this work, a total of 239 isolates from UHT milk samples were obtained. B. cereus s.s. was isolated from 7 samples, B. sporothermodurans from 19 and, G. stearothermophilus from 25 samples. Genes encoding hemolysin (HBL), and non-hemolytic (NHE) enterotoxins were detected in B. cereus s.s. isolates. All isolates of B. cereus s.s. (12) B. sporothermodurans (38), and G. stearothermophilus (47) were selected to verify the ability of biofilm formation in microtiter plates. The results showed all isolates could form biofilms. The OD595 values of biofilm formation varied between 0.14 and 1.04 for B. cereus, 0.20 to 1.87 for B. sporothermodurans, and 0.49 to 2.77 for G. stearothermophilus. The data highlights that the dairy industry needs to reinforce control in the initial quality of the raw material and in CIP cleaning procedures; avoiding biofilm formation and consequently a persistent microbiota in processing plants, which can shelter pathogenic species such as B. cereus s.s.
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Affiliation(s)
- Vanessa Pereira Perez Alonso
- Department of Food Science and Nutrition, School of Food Engineering, State University of Campinas, Campinas, SP, Brazil.
| | - Jéssica de Oliveira Morais
- Department of Food Science and Nutrition, School of Food Engineering, State University of Campinas, Campinas, SP, Brazil
| | - Dirce Yorika Kabuki
- Department of Food Science and Nutrition, School of Food Engineering, State University of Campinas, Campinas, SP, Brazil
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21
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Alford MA, Baquir B, An A, Choi KYG, Hancock REW. NtrBC Selectively Regulates Host-Pathogen Interactions, Virulence, and Ciprofloxacin Susceptibility of Pseudomonas aeruginosa. Front Cell Infect Microbiol 2021; 11:694789. [PMID: 34249781 PMCID: PMC8264665 DOI: 10.3389/fcimb.2021.694789] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/03/2021] [Indexed: 12/11/2022] Open
Abstract
Pseudomonas aeruginosa is a metabolically versatile opportunistic pathogen capable of infecting distinct niches of the human body, including skin wounds and the lungs of cystic fibrosis patients. Eradication of P. aeruginosa infection is becoming increasingly difficult due to the numerous resistance mechanisms it employs. Adaptive resistance is characterized by a transient state of decreased susceptibility to antibiotic therapy that is distinct from acquired or intrinsic resistance, can be triggered by various environmental stimuli and reverted by removal of the stimulus. Further, adaptive resistance is intrinsically linked to lifestyles such as swarming motility and biofilm formation, both of which are important in infections and lead to multi-drug adaptive resistance. Here, we demonstrated that NtrBC, the master of nitrogen control, had a selective role in host colonization and a substantial role in determining intrinsic resistance to ciprofloxacin. P. aeruginosa mutant strains (ΔntrB, ΔntrC and ΔntrBC) colonized the skin but not the respiratory tract of mice as well as WT and, unlike WT, could be reduced or eradicated from the skin by ciprofloxacin. We hypothesized that nutrient availability contributed to these phenomena and found that susceptibility to ciprofloxacin was impacted by nitrogen source in laboratory media. P. aeruginosa ΔntrB, ΔntrC and ΔntrBC also exhibited distinct host interactions, including modestly increased cytotoxicity toward human bronchial epithelial cells, reduced virulence factor production and 10-fold increased uptake by macrophages. These data might explain why NtrBC mutants were less adept at colonizing the upper respiratory tract of mice. Thus, NtrBC represents a link between nitrogen metabolism, adaptation and virulence of the pathogen P. aeruginosa, and could represent a target for eradication of recalcitrant infections in situ.
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Affiliation(s)
- Morgan A Alford
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Beverlie Baquir
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Andy An
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Ka-Yee G Choi
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
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22
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Grekov I, Thöming JG, Kordes A, Häussler S. Evolution of Pseudomonas aeruginosa toward higher fitness under standard laboratory conditions. THE ISME JOURNAL 2021; 15:1165-1177. [PMID: 33273720 PMCID: PMC8115180 DOI: 10.1038/s41396-020-00841-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 11/04/2020] [Accepted: 11/11/2020] [Indexed: 01/29/2023]
Abstract
Identifying genetic factors that contribute to the evolution of adaptive phenotypes in pathogenic bacteria is key to understanding the establishment of infectious diseases. In this study, we performed mutation accumulation experiments to record the frequency of mutations and their effect on fitness in hypermutator strains of the environmental bacterium Pseudomonas aeruginosa in comparison to the host-niche-adapted Salmonella enterica. We demonstrate that P. aeruginosa, but not S. enterica, hypermutators evolve toward higher fitness under planktonic conditions. Adaptation to increased growth performance was accompanied by a reversible perturbing of the local genetic context of membrane and cell wall biosynthesis genes. Furthermore, we observed a fine-tuning of complex regulatory circuits involving multiple di-guanylate modulating enzymes that regulate the transition between fast growing planktonic and sessile biofilm-associated lifestyles. The redundancy and local specificity of the di-guanylate signaling pathways seem to allow a convergent shift toward increased growth performance across niche-adapted clonal P. aeruginosa lineages, which is accompanied by a pronounced heterogeneity of their motility, virulence, and biofilm phenotypes.
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Affiliation(s)
- Igor Grekov
- grid.7490.a0000 0001 2238 295XDepartment of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany ,grid.475435.4Department of Clinical Microbiology, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
| | - Janne Gesine Thöming
- grid.452370.70000 0004 0408 1805Institute of Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, Hannover, Germany ,grid.475435.4Department of Clinical Microbiology, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
| | - Adrian Kordes
- grid.452370.70000 0004 0408 1805Institute of Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, Hannover, Germany ,grid.10423.340000 0000 9529 9877Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Susanne Häussler
- grid.7490.a0000 0001 2238 295XDepartment of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany ,grid.452370.70000 0004 0408 1805Institute of Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, Hannover, Germany ,grid.475435.4Department of Clinical Microbiology, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark ,grid.10423.340000 0000 9529 9877Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
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23
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Pseudomonas aeruginosa: An Audacious Pathogen with an Adaptable Arsenal of Virulence Factors. Int J Mol Sci 2021; 22:ijms22063128. [PMID: 33803907 PMCID: PMC8003266 DOI: 10.3390/ijms22063128] [Citation(s) in RCA: 205] [Impact Index Per Article: 68.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas aeruginosa is a dominant pathogen in people with cystic fibrosis (CF) contributing to morbidity and mortality. Its tremendous ability to adapt greatly facilitates its capacity to cause chronic infections. The adaptability and flexibility of the pathogen are afforded by the extensive number of virulence factors it has at its disposal, providing P. aeruginosa with the facility to tailor its response against the different stressors in the environment. A deep understanding of these virulence mechanisms is crucial for the design of therapeutic strategies and vaccines against this multi-resistant pathogen. Therefore, this review describes the main virulence factors of P. aeruginosa and the adaptations it undergoes to persist in hostile environments such as the CF respiratory tract. The very large P. aeruginosa genome (5 to 7 MB) contributes considerably to its adaptive capacity; consequently, genomic studies have provided significant insights into elucidating P. aeruginosa evolution and its interactions with the host throughout the course of infection.
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24
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Quantitative image analysis of microbial communities with BiofilmQ. Nat Microbiol 2021; 6:151-156. [PMID: 33398098 PMCID: PMC7840502 DOI: 10.1038/s41564-020-00817-4] [Citation(s) in RCA: 122] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 10/19/2020] [Indexed: 01/19/2023]
Abstract
Biofilms are microbial communities that represent a highly abundant form of microbial life on Earth. Inside biofilms, phenotypic and genotypic variations occur in three-dimensional space and time; microscopy and quantitative image analysis are therefore crucial for elucidating their functions. Here, we present BiofilmQ—a comprehensive image cytometry software tool for the automated and high-throughput quantification, analysis and visualization of numerous biofilm-internal and whole-biofilm properties in three-dimensional space and time. BiofilmQ is an image cytometry software tool that enables the visualization, quantification and analysis of biofilm properties, providing insights into their structure and function.
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25
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Martins FG, Melo A, Sousa SF. Databases for the study of biofilms: current status and potential applications. BIOFOULING 2021; 37:96-108. [PMID: 33508968 DOI: 10.1080/08927014.2021.1876849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Biofilms play an important role in health, being associated with >80% of all microbial infections in the body and in the development of antibiotic resistance. Research in this field has continuously produced large volumes of data. Being able to handle all this information will be paramount for progress in this field. However, this places a heavy burden on the development of strategies to gather, organize and make this information available in a way that can be readily and effectively used by those requiring it. Lately, efforts towards this goal have been reported, particularly with the development of Quorumpeps, BiofOmics, BaAMPs, QSPpred, dPABBs, aBiofilm and the Biofilms Structural Database. This work reviews these databases and highlights their applicability and potential, while stressing some of the challenges for the coming years in database development and usage brought about by the use of big data and machine learning.
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Affiliation(s)
- Fábio G Martins
- UCIBIO/REQUIMTE, BioSIM - Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Porto, Portugal
- LAQV/REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
| | - André Melo
- LAQV/REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Porto, Portugal
| | - Sérgio F Sousa
- UCIBIO/REQUIMTE, BioSIM - Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Porto, Portugal
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26
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Abstract
Drug-resistant infections pose a significant risk to global health as pathogenic bacteria become increasingly difficult to treat. The rapid selection of resistant strains through poor antibiotic stewardship has reduced the number of viable treatments and increased morbidity of infections, especially among the immunocompromised. To circumvent such challenges, new strategies are required to stay ahead of emerging resistance trends, yet research and funding for antibiotic development lags other classes of therapeutics. Though the use of metals in therapeutics has been around for centuries, recent strategies have devoted a great deal of effort into the pathways through which bacteria acquire and utilize iron, which is critical for the establishment of infection. To target iron uptake systems, siderophore-drug conjugates have been developed that hijack siderophore-based iron uptake for delivery of antibiotics. While this strategy has produced several potential leads, the use of siderophores in infection is diminished over time when bacteria adapt to utilize heme as an iron source, leading to a need for the development of porphyrin mimetics as therapeutics. The use of such strategies as well as the inclusion of gallium, a redox-inert iron mimic, are herein reviewed.
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Affiliation(s)
- Garrick Centola
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA.
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27
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Schinner S, Preusse M, Kesthely C, Häussler S. Analysis of the organization and expression patterns of the convergent Pseudomonas aeruginosa lasR/rsaL gene pair uncovers mutual influence. Mol Microbiol 2020; 115:643-657. [PMID: 33073409 DOI: 10.1111/mmi.14628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/10/2020] [Accepted: 10/11/2020] [Indexed: 11/30/2022]
Abstract
The two adjacent genes encoding the major Pseudomonas aeruginosa quorum-sensing regulator, LasR, and its opponent, RsaL, overlap in their coding 3' ends and produce mRNA transcripts with long untranslated 3' ends that overlap with the sense transcripts of the gene on the opposing DNA strand. In this study, we evaluated whether the overlapping genes are involved in mutual regulatory events and studied interference by natural antisense transcripts. We introduced various gene expression constructs into a P. aeruginosa PA14 lasR/rsaL double deletion mutant, and found that although complementary RNA is produced, this does not interfere with the sense gene expression levels of lasR and rsaL and does not have functional consequences on down-stream gene regulation. Nevertheless, expression of lasR, but not of rsaL, was shown to be enhanced if transcription was terminated at the end of the respective gene so that no overlapping transcription was allowed. Our data indicate that the natural organization with a partial overlap at the 3' ends of the lasR/rsaL genes gives rise to a system of checks and balances to prevent dominant and unilateral control by LasR over the RsaL transcriptional regulator of opposing function.
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Affiliation(s)
- Silvia Schinner
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Institute of Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Matthias Preusse
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Institute of Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Christopher Kesthely
- Institute of Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Susanne Häussler
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Institute of Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, Hannover, Germany.,Department of Clinical Microbiology, Copenhagen University Hospital -Rigshospitalet, Copenhagen, Denmark.,Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
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28
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Depke T, Thöming JG, Kordes A, Häussler S, Brönstrup M. Untargeted LC-MS Metabolomics Differentiates Between Virulent and Avirulent Clinical Strains of Pseudomonas aeruginosa. Biomolecules 2020; 10:biom10071041. [PMID: 32668735 PMCID: PMC7407980 DOI: 10.3390/biom10071041] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/27/2020] [Accepted: 07/07/2020] [Indexed: 01/02/2023] Open
Abstract
Pseudomonas aeruginosa is a facultative pathogen that can cause, inter alia, acute or chronic pneumonia in predisposed individuals. The gram-negative bacterium displays considerable genomic and phenotypic diversity that is also shaped by small molecule secondary metabolites. The discrimination of virulence phenotypes is highly relevant to the diagnosis and prognosis of P. aeruginosa infections. In order to discover small molecule metabolites that distinguish different virulence phenotypes of P. aeruginosa, 35 clinical strains were cultivated under standard conditions, characterized in terms of virulence and biofilm phenotype, and their metabolomes were investigated by untargeted liquid chromatography-mass spectrometry. The data was both mined for individual candidate markers as well as used to construct statistical models to infer the virulence phenotype from metabolomics data. We found that clinical strains that differed in their virulence and biofilm phenotype also had pronounced divergence in their metabolomes, as underlined by 332 features that were significantly differentially abundant with fold changes greater than 1.5 in both directions. Important virulence-associated secondary metabolites like rhamnolipids, alkyl quinolones or phenazines were found to be strongly upregulated in virulent strains. In contrast, we observed little change in primary metabolism. A hitherto novel cationic metabolite with a sum formula of C12H15N2 could be identified as a candidate biomarker. A random forest model was able to classify strains according to their virulence and biofilm phenotype with an area under the Receiver Operation Characteristics curve of 0.84. These findings demonstrate that untargeted metabolomics is a valuable tool to characterize P. aeruginosa virulence, and to explore interrelations between clinically important phenotypic traits and the bacterial metabolome.
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Affiliation(s)
- Tobias Depke
- Department of Chemical Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany;
| | - Janne Gesine Thöming
- Institute of Molecular Bacteriology, Twincore, Centre for Clinical and Experimental Infection Research, 30625 Hannover, Germany; (J.G.T.); (A.K.); (S.H.)
| | - Adrian Kordes
- Institute of Molecular Bacteriology, Twincore, Centre for Clinical and Experimental Infection Research, 30625 Hannover, Germany; (J.G.T.); (A.K.); (S.H.)
| | - Susanne Häussler
- Institute of Molecular Bacteriology, Twincore, Centre for Clinical and Experimental Infection Research, 30625 Hannover, Germany; (J.G.T.); (A.K.); (S.H.)
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany;
- German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 38124 Braunschweig, Germany
- Correspondence:
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29
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Schinner S, Engelhardt F, Preusse M, Thöming JG, Tomasch J, Häussler S. Genetic determinants of Pseudomonas aeruginosa fitness during biofilm growth. Biofilm 2020; 2:100023. [PMID: 33447809 PMCID: PMC7798452 DOI: 10.1016/j.bioflm.2020.100023] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 02/06/2023] Open
Abstract
Pseudomonas aeruginosa is an environmental bacterium and an opportunistic human pathogen. It is also a well-established model organism to study bacterial adaptation to stressful conditions, such as those encountered during an infection process in the human host. Advancing knowledge on P. aeruginosa adaptation to biofilm growth conditions is bound to reveal novel strategies and targets for the treatment of chronic biofilm-associated infections. Here, we generated transposon insertion libraries in three P. aeruginosa strain backgrounds and determined the relative frequency of each insertion following biofilm growth using transposon sequencing. We demonstrate that in general the SOS response, several tRNA modifying enzymes as well as adaptation to microaerophilic growth conditions play a key role in bacterial survival under biofilm growth conditions. On the other hand, presence of genes involved in motility and PQS signaling were less important during biofilm growth. Several mutants exhibiting transposon insertions in genes detected in our screen were validated for their biofilm growth capabilities and biofilm specific transcriptional responses using independently generated transposon mutants. Our results provide new insights into P. aeruginosa adaptation to biofilm growth conditions. The detection of previously unknown determinants of biofilm survival supports the use of transposon insertion sequencing as a global genomic technology for understanding the establishment of difficult to treat biofilm-associated infections.
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Affiliation(s)
- Silvia Schinner
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Florian Engelhardt
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Matthias Preusse
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Janne Gesine Thöming
- Institute of Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, Hannover, Germany.,Department of Clinical Microbiology, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
| | - Jürgen Tomasch
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Susanne Häussler
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Institute of Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, Hannover, Germany.,Department of Clinical Microbiology, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark.,Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
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