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Şimşek E, Kim K, Lu J, Silver A, Luo N, Lee CT, You L. A 'rich-get-richer' mechanism drives patchy dynamics and resistance evolution in antibiotic-treated bacteria. Mol Syst Biol 2024; 20:880-897. [PMID: 38877321 PMCID: PMC11297297 DOI: 10.1038/s44320-024-00046-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 05/21/2024] [Accepted: 05/23/2024] [Indexed: 06/16/2024] Open
Abstract
Bacteria in nature often form surface-attached communities that initially comprise distinct subpopulations, or patches. For pathogens, these patches can form at infection sites, persist during antibiotic treatment, and develop into mature biofilms. Evidence suggests that patches can emerge due to heterogeneity in the growth environment and bacterial seeding, as well as cell-cell signaling. However, it is unclear how these factors contribute to patch formation and how patch formation might affect bacterial survival and evolution. Here, we demonstrate that a 'rich-get-richer' mechanism drives patch formation in bacteria exhibiting collective survival (CS) during antibiotic treatment. Modeling predicts that the seeding heterogeneity of these bacteria is amplified by local CS and global resource competition, leading to patch formation. Increasing the dose of a non-eradicating antibiotic treatment increases the degree of patchiness. Experimentally, we first demonstrated the mechanism using engineered Escherichia coli and then demonstrated its applicability to a pathogen, Pseudomonas aeruginosa. We further showed that the formation of P. aeruginosa patches promoted the evolution of antibiotic resistance. Our work provides new insights into population dynamics and resistance evolution during surface-attached bacterial growth.
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Affiliation(s)
- Emrah Şimşek
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
- Center for Quantitative Biodesign, Duke University, Durham, NC, 27708, USA
| | - Kyeri Kim
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
- Center for Quantitative Biodesign, Duke University, Durham, NC, 27708, USA
| | - Jia Lu
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
- Center for Quantitative Biodesign, Duke University, Durham, NC, 27708, USA
| | - Anita Silver
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
- Center for Quantitative Biodesign, Duke University, Durham, NC, 27708, USA
| | - Nan Luo
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, 518055, Shenzhen, China
| | - Charlotte T Lee
- Center for Quantitative Biodesign, Duke University, Durham, NC, 27708, USA
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Lingchong You
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.
- Center for Quantitative Biodesign, Duke University, Durham, NC, 27708, USA.
- Center for Genomic and Computational Biology, Duke University, Durham, NC, 27708, USA.
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, 27708, USA.
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2
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Mridha S, Wechsler T, Kümmerli R. Space and genealogy determine inter-individual differences in siderophore gene expression in bacterial colonies. Cell Rep 2024; 43:114106. [PMID: 38625795 DOI: 10.1016/j.celrep.2024.114106] [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: 09/05/2023] [Revised: 02/09/2024] [Accepted: 03/28/2024] [Indexed: 04/18/2024] Open
Abstract
Heterogeneity in gene expression is common among clonal cells in bacteria, although the sources and functions of variation often remain unknown. Here, we track cellular heterogeneity in the bacterium Pseudomonas aeruginosa during colony growth by focusing on siderophore gene expression (pyoverdine versus pyochelin) important for iron nutrition. We find that the spatial position of cells within colonies and non-genetic yet heritable differences between cell lineages are significant sources of cellular heterogeneity, while cell pole age and lifespan have no effect. Regarding functions, our results indicate that cells adjust their siderophore investment strategies along a gradient from the colony center to its edge. Moreover, cell lineages with below-average siderophore investment benefit from lineages with above-average siderophore investment, presumably due to siderophore sharing. Our study highlights that single-cell experiments with dual gene expression reporters can identify sources of gene expression variation of interlinked traits and offer explanations for adaptive benefits in bacteria.
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Affiliation(s)
- Subham Mridha
- Department of Quantitative Biomedicine, University of Zurich, 8057 Zurich, Switzerland; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Tobias Wechsler
- Department of Quantitative Biomedicine, University of Zurich, 8057 Zurich, Switzerland
| | - Rolf Kümmerli
- Department of Quantitative Biomedicine, University of Zurich, 8057 Zurich, Switzerland.
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3
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Kuper TJ, Islam MM, Peirce-Cottler SM, Papin JA, Ford RM. Spatial transcriptome-guided multi-scale framework connects P. aeruginosa metabolic states to oxidative stress biofilm microenvironment. PLoS Comput Biol 2024; 20:e1012031. [PMID: 38669236 PMCID: PMC11051585 DOI: 10.1371/journal.pcbi.1012031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 03/29/2024] [Indexed: 04/28/2024] Open
Abstract
With the generation of spatially resolved transcriptomics of microbial biofilms, computational tools can be used to integrate this data to elucidate the multi-scale mechanisms controlling heterogeneous biofilm metabolism. This work presents a Multi-scale model of Metabolism In Cellular Systems (MiMICS) which is a computational framework that couples a genome-scale metabolic network reconstruction (GENRE) with Hybrid Automata Library (HAL), an existing agent-based model and reaction-diffusion model platform. A key feature of MiMICS is the ability to incorporate multiple -omics-guided metabolic models, which can represent unique metabolic states that yield different metabolic parameter values passed to the extracellular models. We used MiMICS to simulate Pseudomonas aeruginosa regulation of denitrification and oxidative stress metabolism in hypoxic and nitric oxide (NO) biofilm microenvironments. Integration of P. aeruginosa PA14 biofilm spatial transcriptomic data into a P. aeruginosa PA14 GENRE generated four PA14 metabolic model states that were input into MiMICS. Characteristic of aerobic, denitrification, and oxidative stress metabolism, the four metabolic model states predicted different oxygen, nitrate, and NO exchange fluxes that were passed as inputs to update the agent's local metabolite concentrations in the extracellular reaction-diffusion model. Individual bacterial agents chose a PA14 metabolic model state based on a combination of stochastic rules, and agents sensing local oxygen and NO. Transcriptome-guided MiMICS predictions suggested microscale denitrification and oxidative stress metabolic heterogeneity emerged due to local variability in the NO biofilm microenvironment. MiMICS accurately predicted the biofilm's spatial relationships between denitrification, oxidative stress, and central carbon metabolism. As simulated cells responded to extracellular NO, MiMICS revealed dynamics of cell populations heterogeneously upregulating reactions in the denitrification pathway, which may function to maintain NO levels within non-toxic ranges. We demonstrated that MiMICS is a valuable computational tool to incorporate multiple -omics-guided metabolic models to mechanistically map heterogeneous microbial metabolic states to the biofilm microenvironment.
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Affiliation(s)
- Tracy J. Kuper
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia, United States of America
| | - Mohammad Mazharul Islam
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States of America
| | - Shayn M. Peirce-Cottler
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States of America
| | - Jason A. Papin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States of America
| | - Roseanne M Ford
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia, United States of America
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4
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Bottery MJ, Johansen HK, Pitchford JW, Friman VP. Co-occurring microflora and mucin drive Pseudomonas aeruginosa diversification and pathoadaptation. ISME COMMUNICATIONS 2024; 4:ycae043. [PMID: 38707844 PMCID: PMC11067959 DOI: 10.1093/ismeco/ycae043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 03/25/2024] [Accepted: 03/25/2024] [Indexed: 05/07/2024]
Abstract
While several environmental factors contribute to the evolutionary diversification of the pathogenic bacterium Pseudomonas aeruginosa during cystic fibrosis lung infections, relatively little is known about the impact of the surrounding microbiota. By using in vitro experimental evolution, we show that the presence of Stenotrophomonas maltophilia, Staphylococcus aureus, or them both, prevent the evolution of loss of virulence, which repeatedly occurs in the absence of these species due to mutations in regulators of the Pseudomonas Quinolone Signal quorum sensing system, vqsM and pqsR. Moreover, the strength of the effect of co-occurring species is attenuated through changes in the physical environment by the addition of mucin, resulting in selection for phenotypes resembling those evolved in the absence of the co-occurring species. Together, our findings show that variation in mucosal environment and the surrounding polymicrobial environment can determine the evolutionary trajectory of P. aeruginosa, partly explaining its diversification and pathoadaptation from acute to chronic phenotype during cystic fibrosis lung infections.
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Affiliation(s)
- Michael J Bottery
- Division of Evolution Infection and Genomics, School of Biological Sciences, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Helle Krogh Johansen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen 9301, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Jon W Pitchford
- Department of Biology, University of York, Wentworth Way, York YO10 5DD, United Kingdom
- Department of Mathematics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Ville-Petri Friman
- Department of Biology, University of York, Wentworth Way, York YO10 5DD, United Kingdom
- Department of Microbiology, University of Helsinki, Helsinki 00014, Finland
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5
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Hu Y, Yang X, Tai B, Wang G, Zhang X, Yin Y, Xing F. Bacillus amyloliquefaciens A-1 inhibiting fungal spoilage in agricultural products is improved by metabolic engineering of enhancing surfactin yield. Food Res Int 2024; 175:113752. [PMID: 38129052 DOI: 10.1016/j.foodres.2023.113752] [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: 07/25/2023] [Revised: 11/15/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023]
Abstract
Fungi and subsequent mycotoxins contamination in agricultural products have caused enormous losses and great harm to human and animal health. Biological control has attracted the attention of researchers due to its advantages, including mild conditions, low cost, high efficiency and low nutrient loss. In this study, a newly isolated strain Bacillus amyloliquefaciens A-1 (A-1), was screened for its ability to inhibit the growth and Aflatoxin B1 (AFB1) production of Aspergillus flavus NRRL 3357. Electron microscopy results revealed that mycelium and conidia of A. flavus were destroyed by A-1, affecting hyphae, cell walls, cell membranes and organelles. RNA-seq analysis indicated disturbance in gene expression profiles of A. flavus, including amino acid degradation and starch and sucrose metabolism pathways. Importantly, the biosynthesis of AFB1 was significantly inhibited by the down-regulation of key regulatory genes, aflR and aflS, and the simultaneous down-regulation of most structural genes. Genome analysis predicted six secondary metabolites biosynthetic gene clusters. Then, four surfactin synthesized by cluster C were identified as the main active substance of A-1 using HPLC-Q-TOF-MS. The addition of alanine, threonine, Fe2+ increased surfactin production. Notably, the overexpression of comX also improved surfactin production. The vivo test results indicated that A-1 could significantly inhibit the decay of pear by Aspergillus westerdijkiae, and the mildew of maize and peanuts. Especially, the overexpression of comX in A-1 could enhance the inhibitory activity. In conclusion, the inhibition mechanism of A-1 was revealed, and comX was found can improve the production of surfactin and subsequent activities, which provides the scientific basis for the development of biocontrol agents to reduce spoilage in agricultural products.
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Affiliation(s)
- Yafan Hu
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs / Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Xu Yang
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs / Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Bowen Tai
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs / Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Gang Wang
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs / Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.
| | - Xinlong Zhang
- Shandong Xinfurui Agricultural Science and Technology Co., Ltd. Liaocheng 252000, PR China
| | - Yixuan Yin
- Shandong Xinfurui Agricultural Science and Technology Co., Ltd. Liaocheng 252000, PR China
| | - Fuguo Xing
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs / Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.
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6
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Jung H. A pore-scale reactive transport modeling study for quorum sensing-driven biofilm dispersal in heterogeneous porous media. Math Biosci 2024; 367:109126. [PMID: 38070765 DOI: 10.1016/j.mbs.2023.109126] [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: 08/21/2023] [Revised: 10/26/2023] [Accepted: 12/06/2023] [Indexed: 12/17/2023]
Abstract
Microorganisms regulate the expression of energetically expensive phenotypes via a collective decision-making mechanism known as quorum sensing (QS). This study investigates the intricate dynamics of biofilm growth and QS-controlled biofilm dispersal in heterogeneous porous media, employing a pore-scale reactive transport modeling approach. Model simulations carried out under various fluid flow conditions and biofilm growth scenarios reveal that QS processes are influenced not only by the biomass density of biofilm colonies but also by a complex interplay between pore architecture, flow velocity, and the rates of biofilm growth and dispersal. This study demonstrates that pore architecture controls the initiation of QS processes and advection gives rise to oscillatory growth of biofilms. Such oscillation is suppressed if biofilm dynamics are in favor of sustaining a sufficiently high signal concentration, such as fast growth or slow dispersal rates. By establishing a mathematical framework, this study contributes to the fundamental understanding of QS-controlled biofilm dynamics in complex environments.
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Affiliation(s)
- Heewon Jung
- Department of Geological Sciences, Chungnam National University, Daejeon 34134, South Korea.
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7
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McAtamney A, Heaney C, Lizama-Chamu I, Sanchez LM. Reducing Mass Confusion over the Microbiome. Anal Chem 2023; 95:16775-16785. [PMID: 37934885 PMCID: PMC10841885 DOI: 10.1021/acs.analchem.3c02408] [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] [Indexed: 11/09/2023]
Abstract
As genetic tools continue to emerge and mature, more information is revealed about the identity and diversity of microbial community members. Genetic tools can also be used to make predictions about the chemistry that bacteria and fungi produce to function and communicate with one another and the host. Ongoing efforts to identify these products and link genetic information to microbiome chemistry rely on analytical tools. This tutorial highlights recent advancements in microbiome studies driven by techniques in mass spectrometry.
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Affiliation(s)
- Allyson McAtamney
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States
| | - Casey Heaney
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States
| | - Itzel Lizama-Chamu
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States
| | - Laura M Sanchez
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States
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8
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Myckatyn TM, Duran Ramirez JM, Walker JN, Hanson BM. Management of Biofilm with Breast Implant Surgery. Plast Reconstr Surg 2023; 152:919e-942e. [PMID: 37871028 DOI: 10.1097/prs.0000000000010791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
LEARNING OBJECTIVES After studying this article, the participant should be able to: 1. Understand how bacteria negatively impact aesthetic and reconstructive breast implants. 2. Understand how bacteria infect breast implants. 3. Understand the evidence associated with common implant infection-prevention strategies, and their limitations. 4. Understand why implementation of bacteria-mitigation strategies such as antibiotic administration or "no-touch" techniques may not indefinitely prevent breast implant infection. SUMMARY Bacterial infection of aesthetic and reconstructive breast implants is a common and expensive problem. Subacute infections or chronic capsular contractures leading to device explantation are the most commonly documented sequelae. Although bench and translational research underscores the complexities of implant-associated infection, high-quality studies with adequate power, control groups, and duration of follow-up are lacking. Common strategies to minimize infections use antibiotics-administered systemically, in the breast implant pocket, or by directly bathing the implant before insertion-to limit bacterial contamination. Limiting contact between the implant and skin or breast parenchyma represents an additional common strategy. The clinical prevention of breast implant infection is challenged by the clean-contaminated nature of breast parenchyma, and the variable behavior of not only specific bacterial species but also their strains. These factors impact bacterial virulence and antibiotic resistance.
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Affiliation(s)
- Terence M Myckatyn
- From the Division of Plastic and Reconstructive Surgery, Washington University in St. Louis School of Medicine
| | | | - Jennifer N Walker
- Department of Microbiology and Molecular Genetics
- Center for Infectious Diseases, Department of Epidemiology, School of Public Health, University of Texas Health Science Center at Houston
| | - Blake M Hanson
- Center for Antimicrobial Resistance and Microbial Genomics, McGovern Medical School
- Center for Infectious Diseases, Department of Epidemiology, School of Public Health, University of Texas Health Science Center at Houston
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9
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García-Diéguez L, Diaz-Tang G, Marin Meneses E, Cruise V, Barraza I, Craddock TJ, Smith RP. Periodically disturbing biofilms reduces expression of quorum sensing-regulated virulence factors in Pseudomonas aeruginosa. iScience 2023; 26:106843. [PMID: 37255658 PMCID: PMC10225924 DOI: 10.1016/j.isci.2023.106843] [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: 03/19/2023] [Revised: 04/26/2023] [Accepted: 05/04/2023] [Indexed: 06/01/2023] Open
Abstract
Pseudomonas aeruginosa uses quorum sensing to regulate the expression of virulence factors. In static environments, spatial structures, such as biofilms, can increase the expression of these virulence factors. However, in natural settings, biofilms are exposed to physical forces that disrupt spatial structure, which may affect the expression of virulence factors regulated by quorum sensing. We show that periodically disturbing biofilms composed of P. aeruginosa using a physical force reduces the expression of quorum sensing-regulated virulence factors. At an intermediate disturbance frequency, the expression of virulence factors in the las, rhl, and pqs regulons is reduced. Mathematical modeling suggests that perturbation of the pqsR receptor is critical for this reduction. Removing the lasR receptor enhances the reduction in the expression of virulence factors as a result of disturbance. Our results allow identification of environments where virulence is reduced and implicate the lasR receptor as having a buffering role against disturbance.
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Affiliation(s)
- Laura García-Diéguez
- Department of Biological Sciences, Halmos College of Arts and Science, Nova Southeastern University, Fort Lauderdale FL 33314, USA
| | - Gabriela Diaz-Tang
- Department of Biological Sciences, Halmos College of Arts and Science, Nova Southeastern University, Fort Lauderdale FL 33314, USA
| | - Estefania Marin Meneses
- Department of Biological Sciences, Halmos College of Arts and Science, Nova Southeastern University, Fort Lauderdale FL 33314, USA
| | - Vanessa Cruise
- Department of Biological Sciences, Halmos College of Arts and Science, Nova Southeastern University, Fort Lauderdale FL 33314, USA
| | - Ivana Barraza
- Department of Biological Sciences, Halmos College of Arts and Science, Nova Southeastern University, Fort Lauderdale FL 33314, USA
| | - Travis J.A. Craddock
- Clinical Systems Biology Group, Institute for Neuro-Immune Medicine, Nova Southeastern University, Fort Lauderdale FL 33314, USA
- Department of Psychology & Neuroscience, College of Psychology, Nova Southeastern University, Fort Lauderdale FL 33314, USA
- Department of Computer Science, College of Engineering and Computing, Nova Southeastern University, Fort Lauderdale FL 33314, USA
- Department of Clinical Immunology, College of Osteopathic Medicine, Nova Southeastern University, Fort Lauderdale FL 33314, USA
| | - Robert P. Smith
- Department of Biological Sciences, Halmos College of Arts and Science, Nova Southeastern University, Fort Lauderdale FL 33314, USA
- Cell Therapy Institute, Kiran Patel College of Allopathic Medicine, Nova Southeastern University, Fort Lauderdale FL 33314, USA
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10
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Moreno-Gámez S, Hochberg ME, van Doorn GS. Quorum sensing as a mechanism to harness the wisdom of the crowds. Nat Commun 2023; 14:3415. [PMID: 37296108 PMCID: PMC10256802 DOI: 10.1038/s41467-023-37950-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 04/05/2023] [Indexed: 06/12/2023] Open
Abstract
Bacteria release and sense small molecules called autoinducers in a process known as quorum sensing. The prevailing interpretation of quorum sensing is that by sensing autoinducer concentrations, bacteria estimate population density to regulate the expression of functions that are only beneficial when carried out by a sufficiently large number of cells. However, a major challenge to this interpretation is that the concentration of autoinducers strongly depends on the environment, often rendering autoinducer-based estimates of cell density unreliable. Here we propose an alternative interpretation of quorum sensing, where bacteria, by releasing and sensing autoinducers, harness social interactions to sense the environment as a collective. Using a computational model we show that this functionality can explain the evolution of quorum sensing and arises from individuals improving their estimation accuracy by pooling many imperfect estimates - analogous to the 'wisdom of the crowds' in decision theory. Importantly, our model reconciles the observed dependence of quorum sensing on both population density and the environment and explains why several quorum sensing systems regulate the production of private goods.
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Affiliation(s)
- Stefany Moreno-Gámez
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands.
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| | - Michael E Hochberg
- ISEM, Université de Montpellier, CNRS, IRD, EPHE, 34095, Montpellier, France
- Santa Fe Institute, Santa Fe, NM, 87501, USA
| | - G S van Doorn
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands
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11
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Lewin GR, Kapur A, Cornforth DM, Duncan RP, Diggle FL, Moustafa DA, Harrison SA, Skaar EP, Chazin WJ, Goldberg JB, Bomberger JM, Whiteley M. Application of a quantitative framework to improve the accuracy of a bacterial infection model. Proc Natl Acad Sci U S A 2023; 120:e2221542120. [PMID: 37126703 PMCID: PMC10175807 DOI: 10.1073/pnas.2221542120] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 04/07/2023] [Indexed: 05/03/2023] Open
Abstract
Laboratory models are critical to basic and translational microbiology research. Models serve multiple purposes, from providing tractable systems to study cell biology to allowing the investigation of inaccessible clinical and environmental ecosystems. Although there is a recognized need for improved model systems, there is a gap in rational approaches to accomplish this goal. We recently developed a framework for assessing the accuracy of microbial models by quantifying how closely each gene is expressed in the natural environment and in various models. The accuracy of the model is defined as the percentage of genes that are similarly expressed in the natural environment and the model. Here, we leverage this framework to develop and validate two generalizable approaches for improving model accuracy, and as proof of concept, we apply these approaches to improve models of Pseudomonas aeruginosa infecting the cystic fibrosis (CF) lung. First, we identify two models, an in vitro synthetic CF sputum medium model (SCFM2) and an epithelial cell model, that accurately recapitulate different gene sets. By combining these models, we developed the epithelial cell-SCFM2 model which improves the accuracy of over 500 genes. Second, to improve the accuracy of specific genes, we mined publicly available transcriptome data, which identified zinc limitation as a cue present in the CF lung and absent in SCFM2. Induction of zinc limitation in SCFM2 resulted in accurate expression of 90% of P. aeruginosa genes. These approaches provide generalizable, quantitative frameworks for microbiological model improvement that can be applied to any system of interest.
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Affiliation(s)
- Gina R. Lewin
- School of Biological Sciences and Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA30332
- Emory-Children’s Cystic Fibrosis Center, Atlanta, GA30332
| | - Ananya Kapur
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA15219
| | - Daniel M. Cornforth
- School of Biological Sciences and Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA30332
- Emory-Children’s Cystic Fibrosis Center, Atlanta, GA30332
| | - Rebecca P. Duncan
- Emory-Children’s Cystic Fibrosis Center, Atlanta, GA30332
- Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, GA30322
| | - Frances L. Diggle
- School of Biological Sciences and Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA30332
- Emory-Children’s Cystic Fibrosis Center, Atlanta, GA30332
| | - Dina A. Moustafa
- Emory-Children’s Cystic Fibrosis Center, Atlanta, GA30332
- Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, GA30322
| | - Simone A. Harrison
- Department of Biochemistry, Vanderbilt University, Nashville, TN37232
- Department of Chemistry, Vanderbilt University, Nashville, TN37232
- Center for Structural Biology, Vanderbilt University, Nashville, TN37232
| | - Eric P. Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN37232
| | - Walter J. Chazin
- Department of Biochemistry, Vanderbilt University, Nashville, TN37232
- Department of Chemistry, Vanderbilt University, Nashville, TN37232
- Center for Structural Biology, Vanderbilt University, Nashville, TN37232
| | - Joanna B. Goldberg
- Emory-Children’s Cystic Fibrosis Center, Atlanta, GA30332
- Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, GA30322
| | - Jennifer M. Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA15219
| | - Marvin Whiteley
- School of Biological Sciences and Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA30332
- Emory-Children’s Cystic Fibrosis Center, Atlanta, GA30332
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12
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Pellielo G, Agyapong ED, Pinton P, Rimessi A. Control of mitochondrial functions by Pseudomonas aeruginosa in cystic fibrosis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2023; 377:19-43. [PMID: 37268349 DOI: 10.1016/bs.ircmb.2023.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cystic fibrosis (CF) is a genetic disease characterized by mutations of cystic fibrosis transmembrane conductance regulator (CFTR) gene, which lead to a dysfunctional chloride and bicarbonate channel. Abnormal mucus viscosity, persistent infections and hyperinflammation that preferentially affect the airways, referred to the pathogenesis of CF lung disease. It has largely demonstrated that Pseudomonas aeruginosa (P. aeruginosa) represents the most important pathogen that affect CF patients, leading to worsen inflammation by stimulating pro-inflammatory mediators release and tissue destruction. The conversion to mucoid phenotype and formation of biofilms, together with the increased frequency of mutations, are only few changes that characterize the P. aeruginosa's evolution during CF lung chronic infection. Recently, mitochondria received increasing attention due to their involvement in inflammatory-related diseases, including in CF. Alteration of mitochondrial homeostasis is sufficient to stimulate immune response. Exogenous or endogenous stimuli that perturb mitochondrial activity are used by cells, which, through the mitochondrial stress, potentiate immunity programs. Studies show the relationship between mitochondria and CF, supporting the idea that mitochondrial dysfunction endorses the exacerbation of inflammatory responses in CF lung. In particular, evidences suggest that mitochondria in CF airway cells are more susceptible to P. aeruginosa infection, with consequent detrimental effects that lead to amplify the inflammatory signals. This review discusses the evolution of P. aeruginosa in relationship with the pathogenesis of CF, a fundamental step to establish chronic infection in CF lung disease. Specifically, we focus on the role of P. aeruginosa in the exacerbation of inflammatory response, by triggering mitochondria in CF.
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Affiliation(s)
- Giulia Pellielo
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, Ferrara, Italy
| | - Esther Densu Agyapong
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, Ferrara, Italy
| | - Paolo Pinton
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, Ferrara, Italy; Center of research for innovative therapies in cystic fibrosis, University of Ferrara, Ferrara, Italy
| | - Alessandro Rimessi
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, Ferrara, Italy; Center of research for innovative therapies in cystic fibrosis, University of Ferrara, Ferrara, Italy.
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13
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Sanya DRA, Onésime D, Vizzarro G, Jacquier N. Recent advances in therapeutic targets identification and development of treatment strategies towards Pseudomonas aeruginosa infections. BMC Microbiol 2023; 23:86. [PMID: 36991325 PMCID: PMC10060139 DOI: 10.1186/s12866-023-02832-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 03/21/2023] [Indexed: 03/31/2023] Open
Abstract
The opportunistic human pathogen Pseudomonas aeruginosa is the causal agent of a wide variety of infections. This non-fermentative Gram-negative bacillus can colonize zones where the skin barrier is weakened, such as wounds or burns. It also causes infections of the urinary tract, respiratory system or bloodstream. P. aeruginosa infections are common in hospitalized patients for which multidrug-resistant, respectively extensively drug-resistant isolates can be a strong contributor to a high rate of in-hospital mortality. Moreover, chronic respiratory system infections of cystic fibrosis patients are especially concerning, since very tedious to treat. P. aeruginosa exploits diverse cell-associated and secreted virulence factors, which play essential roles in its pathogenesis. Those factors encompass carbohydrate-binding proteins, quorum sensing that monitor the production of extracellular products, genes conferring extensive drug resistance, and a secretion system to deliver effectors to kill competitors or subvert host essential functions. In this article, we highlight recent advances in the understanding of P. aeruginosa pathogenicity and virulence as well as efforts for the identification of new drug targets and the development of new therapeutic strategies against P. aeruginosa infections. These recent advances provide innovative and promising strategies to circumvent infection caused by this important human pathogen.
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Affiliation(s)
| | - Djamila Onésime
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, 78350, France
| | - Grazia Vizzarro
- Institute of Microbiology, University Hospital and University of Lausanne, Lausanne, 1011, Switzerland
- Present Address: Laboratory of Molecular Microbiology, Global Health Institute, School of Life Sciences, Station 19, EPFL-SV-UPBLO, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland
| | - Nicolas Jacquier
- Institute of Microbiology, University Hospital and University of Lausanne, Lausanne, 1011, Switzerland.
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14
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Dal Co A, Ackermann M, van Vliet S. Spatial self-organization of metabolism in microbial systems: A matter of enzymes and chemicals. Cell Syst 2023; 14:98-108. [PMID: 36796335 DOI: 10.1016/j.cels.2022.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/14/2022] [Accepted: 12/21/2022] [Indexed: 02/17/2023]
Abstract
Most bacteria live in dense, spatially structured communities such as biofilms. The high density allows cells to alter the local microenvironment, whereas the limited mobility can cause species to become spatially organized. Together, these factors can spatially organize metabolic processes within microbial communities so that cells in different locations perform different metabolic reactions. The overall metabolic activity of a community depends both on how metabolic reactions are arranged in space and on how they are coupled, i.e., how cells in different regions exchange metabolites. Here, we review mechanisms that lead to the spatial organization of metabolic processes in microbial systems. We discuss factors that determine the length scales over which metabolic activities are arranged in space and highlight how the spatial organization of metabolic processes affects the ecology and evolution of microbial communities. Finally, we define key open questions that we believe should be the main focus of future research.
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Affiliation(s)
- Alma Dal Co
- Department of Computational Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Martin Ackermann
- Department of Environmental Systems Science, ETH Zurich, 8092 Zurich, Switzerland; Department of Environmental Microbiology, Eawag, 8600 Duebendorf, Switzerland.
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15
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Ren A, Jia M, Liu J, Zhou T, Wu L, Dong T, Cai Z, Qu J, Liu Y, Yang L, Zhang Y. Acquisition of T6SS Effector TseL Contributes to the Emerging of Novel Epidemic Strains of Pseudomonas aeruginosa. Microbiol Spectr 2023; 11:e0330822. [PMID: 36546869 PMCID: PMC9927574 DOI: 10.1128/spectrum.03308-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 11/16/2022] [Indexed: 12/24/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen with multiple strategies to interact with other microbes and host cells, gaining fitness in complicated infection sites. The contact-dependent type VI secretion system (T6SS) is one critical secretion apparatus involved in both interbacterial competition and pathogenesis. To date, only limited numbers of T6SS-effectors have been clearly characterized in P. aeruginosa laboratory strains, and the importance of T6SS diversity in the evolution of clinical P. aeruginosa remains unclear. Recently, we characterized a P. aeruginosa clinical strain LYSZa7 from a COVID-19 patient, which adopted complex genetic adaptations toward chronic infections. Bioinformatic analysis has revealed a putative type VI secretion system (T6SS) dependent lipase effector in LYSZa7, which is a homologue of TseL in Vibrio cholerae and is widely distributed in pathogens. We experimentally validated that this TseL homologue belongs to the Tle2, a subfamily of T6SS-lipase effectors; thereby, we name this effector TseL (TseLPA in this work). Further, we showed the lipase-dependent bacterial toxicity of TseLPA, which primarily targets bacterial periplasm. The toxicity of TseLPA can be neutralized by two immunity proteins, TsiP1 and TsiP2, which are encoded upstream of tseL. In addition, we proved this TseLPA contributes to bacterial pathogenesis by promoting bacterial internalization into host cells. Our study suggests that clinical bacterial strains employ a diversified group of T6SS effectors for interbacterial competition and might contribute to emerging of new epidemic clonal lineages. IMPORTANCE Pseudomonas aeruginosa is one predominant pathogen that causes hospital-acquired infections and is one of the commonest coinfecting bacteria in immunocompromised patients and chronic wounds. This bacterium harbors a diverse accessory genome with a high frequency of gene recombination, rendering its population highly heterogeneous. Numerous Pa lineages coexist in the biofilm, where successful epidemic clonal lineage or strain-specific type commonly acquires genes to increase its fitness over the other organisms. Current studies of Pa genomic diversity commonly focused on antibiotic resistant genes and novel phages, overlooking the contribution of type VI secretion system (T6SS). We characterized a Pa clinical strain LYSZa7 from a COVID-19 patient, which adopted complex genetic adaptations toward chronic infections. We report, in this study, a novel T6SS-lipase effector that is broadly distributed in Pa clinical isolates and other predominant pathogens. The study suggests that hospital transmission may raise the emergence of new epidemic clonal lineages with specified T6SS effectors.
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Affiliation(s)
- Anmin Ren
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, People’s Republic of China
| | - Minlu Jia
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, People’s Republic of China
| | - Jihong Liu
- Medical Research Center, Southern University of Science and Technology Hospital, Shenzhen, Guangdong, People’s Republic of China
| | - Tian Zhou
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, People’s Republic of China
| | - Liwen Wu
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, People’s Republic of China
| | - Tao Dong
- School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, People’s Republic of China
| | - Zhao Cai
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, People’s Republic of China
| | - Jiuxin Qu
- Shenzhen Third People’s Hospital, The Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, Guangdong, People’s Republic of China
| | - Yang Liu
- Medical Research Center, Southern University of Science and Technology Hospital, Shenzhen, Guangdong, People’s Republic of China
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, People’s Republic of China
- Shenzhen Third People’s Hospital, The Second Affiliated Hospital of Southern University of Science and Technology, National Clinical Research Center for Infectious Disease, Shenzhen, Guangdong, People’s Republic of China
- Key University Laboratory of Metabolism and Health of Guangdong, Southern University of Science and Technology, Shenzhen, Guangdong, People’s Republic of China
| | - Yingdan Zhang
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, People’s Republic of China
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16
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Weaver BP, Haselwandter CA, Boedicker JQ. Stochastic effects in bacterial communication mediated by extracellular vesicles. Phys Rev E 2023; 107:024409. [PMID: 36932546 DOI: 10.1103/physreve.107.024409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
Quorum sensing (QS) allows bacterial cells to sense changes in local cell density and, hence, to regulate multicellular processes, including biofilm formation, regulation of virulence, and horizontal gene transfer. While, traditionally, QS was thought to involve the exchange of extracellular signal molecules free in solution, recent experiments have shown that for some bacterial systems a substantial fraction of signal molecules are packaged and delivered in extracellular vesicles. How the packaging of signal molecules in extracellular vesicles influences the ability of cells to communicate and coordinate multicellular behaviors remains largely unknown. We present here a stochastic reaction-diffusion model of QS that accounts for the exchange of both freely diffusing and vesicle-associated signal molecules. We find that the delivery of signal molecules via extracellular vesicles amplifies local fluctuations in the signal concentration, which can strongly affect the dynamics and spatial range of bacterial communication. For systems with multiple bacterial colonies, extracellular vesicles provide an alternate pathway for signal transport between colonies, and may be crucial for long-distance signal exchange in environments with strong degradation of free signal molecules.
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Affiliation(s)
- Brian P Weaver
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA
| | - Christoph A Haselwandter
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California 90089, USA
| | - James Q Boedicker
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA
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17
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Kaur N, Dey P. Bacterial Exopolysaccharides as Emerging Bioactive Macromolecules: From Fundamentals to Applications. Res Microbiol 2022; 174:104024. [PMID: 36587857 DOI: 10.1016/j.resmic.2022.104024] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/26/2022] [Indexed: 12/31/2022]
Abstract
Microbial exopolysaccharides (EPS) are extracellular carbohydrate polymers forming capsules or slimy coating around the cells. EPS can be secreted by various bacterial genera that can help bacterial cells in attachment, environmental adaptation, stress tolerance and are an integral part of microbial biofilms. Several gut commensals (e.g., Lactobacillus, Bifidobacterium) produce EPS that possess diverse bioactivities. Bacterial EPS also has extensive commercial applications in the pharmaceutical and food industries. Owing to the structural and functional diversity, genetic and metabolic engineering strategies are currently employed to increase EPS production. Therefore, the current review provides a comprehensive overview of the fundamentals of bacterial exopolysaccharides, including their classification, source, biosynthetic pathways, and functions in the microbial community. The review also provides an overview of the diverse bioactivities of microbial EPS, including immunomodulatory, anti-diabetic, anti-obesity, and anti-cancer properties. Since several gut microbes are EPS producers and gut microbiota helps maintain a functional gut barrier, emphasis has been given to the intestinal-level bioactivities of the gut microbial EPS. Collectively, the review provides a comprehensive overview of microbial bioactive exopolysaccharides.
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Affiliation(s)
- Navneet Kaur
- Department of Biotechnology, Thapar Institute of Engineering and Technology, Patiala, Punjab, India
| | - Priyankar Dey
- Department of Biotechnology, Thapar Institute of Engineering and Technology, Patiala, Punjab, India.
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18
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Lichtenberg M, Kvich L, Larsen SLB, Jakobsen TH, Bjarnsholt T. Inoculum Concentration Influences Pseudomonas aeruginosa Phenotype and Biofilm Architecture. Microbiol Spectr 2022; 10:e0313122. [PMID: 36354337 PMCID: PMC9769529 DOI: 10.1128/spectrum.03131-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 10/21/2022] [Indexed: 11/12/2022] Open
Abstract
In infections, bacterial cells are often found as relatively small multicellular aggregates characterized by a heterogeneous distribution of phenotype, genotype, and growth rates depending on their surrounding microenvironment. Many laboratory models fail to mimic these characteristics, and experiments are often initiated from planktonic bacteria given optimal conditions for rapid growth without concerns about the microenvironmental characteristics during biofilm maturation. Therefore, we investigated how the initial bacterial concentration (henceforth termed the inoculum) influences the microenvironment during initial growth and how this affects the sizes and distribution of developed aggregates in an embedded biofilm model-the alginate bead biofilm model. Following 24 h of incubation, the viable biomass was independent of starting inoculum but with a radically different microenvironment which led to differences in metabolic activity depending on the inoculum. The inoculum also affected the number of cells surviving treatment with the antibiotic tobramycin, where the highest inoculum showed higher survival rates than the lowest inoculum. The change in antibiotic tolerance was correlated with cell-specific RNA content and O2 consumption rates, suggesting a direct role of metabolic activity. Thus, the starting number of bacteria results in different phenotypic trajectories governed by different microenvironmental characteristics, and we demonstrate some of the possible implications of such physiological gradients on the outcome of in vitro experiments. IMPORTANCE Biofilm aggregates grown in the alginate bead biofilm model bear resemblance to features of in vivo biofilms. Here, we show that changing the initial concentration of bacteria in the biofilm model leads to widely different behavior of the bacteria following an incubation period. This difference is influenced by the local conditions experienced by the bacteria during growth, which impact their response to antibiotic treatment. Our study provides a framework for manipulating aggregate sizes in in vitro biofilm models. It underlines the importance of how experiments are initiated, which can profoundly impact the outcomes and interpretation of microbiological experiments.
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Affiliation(s)
- Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Lasse Kvich
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Sara Louise Borregaard Larsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Tim Holm Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
- Department of Clinical Microbiology, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
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19
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Precise spatial structure impacts antimicrobial susceptibility of S. aureus in polymicrobial wound infections. Proc Natl Acad Sci U S A 2022; 119:e2212340119. [PMID: 36520668 PMCID: PMC9907066 DOI: 10.1073/pnas.2212340119] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
A hallmark of microbial ecology is that interactions between members of a community shape community function. This includes microbial communities in human infections, such as chronic wounds, where interactions can result in more severe diseases. Staphylococcus aureus is the most common organism isolated from human chronic wound infections and has been shown to have both cooperative and competitive interactions with Pseudomonas aeruginosa. Still, despite considerable study, most interactions between these microbes have been characterized using in vitro well-mixed systems, which do not recapitulate the infection environment. Here, we characterized interactions between S. aureus and P. aeruginosa in chronic murine wounds, focusing on the role that both macro- and micro-scale spatial structures play in disease. We discovered that S. aureus and P. aeruginosa coexist at high cell densities in murine wounds. High-resolution imaging revealed that these microbes establish a patchy distribution, only occupying 5 to 25% of the wound volume. Using a quantitative framework, we identified a precise spatial structure at both the macro (mm)- and micro (µm)-scales, which was largely mediated by P. aeruginosa production of the antimicrobial 2-heptyl-4-hydroxyquinoline N-oxide, while the antimicrobial pyocyanin had no impact. Finally, we discovered that this precise spatial structure enhances S. aureus tolerance to aminoglycoside antibiotics but not vancomycin. Our results provide mechanistic insights into the biogeography of S. aureus and P. aeruginosa coinfected wounds and implicate spatial structure as a key determinant of antimicrobial tolerance in wound infections.
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20
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Nyffeler KE, Santa EE, Blackwell HE. Small Molecules with Either Receptor-Selective or Pan-Receptor Activity in the Three LuxR-Type Receptors that Regulate Quorum Sensing in Pseudomonas aeruginosa. ACS Chem Biol 2022; 17:2979-2985. [PMID: 36239990 PMCID: PMC9675725 DOI: 10.1021/acschembio.2c00675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Quorum sensing (QS) allows bacteria to assess their local cell density using chemical signals and plays a prominent role in the ability of common pathogens to infect a host. Non-native molecules capable of attenuating bacterial QS represent useful tools to explore the role of this pathway in virulence. As individual bacterial species can have multiple QS systems and/or reside in mixed communities with other bacteria capable of QS, chemical tools that are either selective for one QS system or "pan-active" and target all QS pathways are of significant interest. Herein we outline the analysis of a set of compounds reported to target one QS system in Pseudomonas aeruginosa for their activity in two other QS circuits in this pathogen and the discovery of molecules with novel activity profiles, including subsets that agonize all three QS systems, agonize one but antagonize the other two, or strongly antagonize just one.
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Affiliation(s)
- Kayleigh E. Nyffeler
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706, USA,Microbiology Doctoral Training Program, University of Wisconsin–Madison, 1550 Linden Dr., Madison, WI 53706, USA
| | - Emma E. Santa
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706, USA
| | - Helen E. Blackwell
- Department of Chemistry, University of Wisconsin–Madison, 1101 University Ave., Madison, WI 53706, USA
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21
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Crisan CV, Goldberg JB. Antibacterial contact-dependent proteins secreted by Gram-negative cystic fibrosis respiratory pathogens. Trends Microbiol 2022; 30:986-996. [PMID: 35487848 PMCID: PMC9474641 DOI: 10.1016/j.tim.2022.03.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/25/2022] [Accepted: 03/29/2022] [Indexed: 01/11/2023]
Abstract
Cystic fibrosis (CF) is a genetic disease that affects almost 100 000 people worldwide. CF patients suffer from chronic bacterial airway infections that are often polymicrobial and are the leading cause of mortality. Interactions between pathogens modulate expression of genes responsible for virulence and antibiotic resistance. One of the ways bacteria can interact is through contact-dependent systems, which secrete antibacterial proteins (effectors) that confer advantages to cells that harbor them. Here, we highlight recent work that describes effectors used by Gram-negative CF pathogens to eliminate competitor bacteria. Understanding the mechanisms of secreted effectors may lead to novel insights into the ecology of bacteria that colonize respiratory tracts and could also pave the way for the design of new therapeutics.
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Affiliation(s)
- Cristian V Crisan
- Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, GA, USA; Emory+Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, USA
| | - Joanna B Goldberg
- Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, GA, USA; Emory+Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, USA.
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22
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Pseudomonas aeruginosa Production of Hydrogen Cyanide Leads to Airborne Control of Staphylococcus aureus Growth in Biofilm and In Vivo Lung Environments. mBio 2022; 13:e0215422. [PMID: 36129311 DOI: 10.1128/mbio.02154-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Diverse bacterial volatile compounds alter bacterial stress responses and physiology, but their contribution to population dynamics in polymicrobial communities is not well known. In this study, we showed that airborne volatile hydrogen cyanide (HCN) produced by a wide range of Pseudomonas aeruginosa clinical strains leads to at-a-distance in vitro inhibition of the growth of a wide array of Staphylococcus aureus strains. We determined that low-oxygen environments not only enhance P. aeruginosa HCN production but also increase S. aureus sensitivity to HCN, which impacts P. aeruginosa-S. aureus competition in microaerobic in vitro mixed biofilms as well as in an in vitro cystic fibrosis lung sputum medium. Consistently, we demonstrated that production of HCN by P. aeruginosa controls S. aureus growth in a mouse model of airways coinfected by P. aeruginosa and S. aureus. Our study therefore demonstrates that P. aeruginosa HCN contributes to local and distant airborne competition against S. aureus and potentially other HCN-sensitive bacteria in contexts relevant to cystic fibrosis and other polymicrobial infectious diseases. IMPORTANCE Airborne volatile compounds produced by bacteria are often only considered attractive or repulsive scents, but they also directly contribute to bacterial physiology. Here, we showed that volatile hydrogen cyanide (HCN) released by a wide range of Pseudomonas aeruginosa strains controls Staphylococcus aureus growth in low-oxygen in vitro biofilms or aggregates and in vivo lung environments. These results are of pathophysiological relevance, since lungs of cystic fibrosis patients are known to present microaerobic areas and to be commonly associated with the presence of S. aureus and P. aeruginosa in polymicrobial communities. Our study therefore provides insights into how a bacterial volatile compound can contribute to the exclusion of S. aureus and other HCN-sensitive competitors from P. aeruginosa ecological niches. It opens new perspectives for the management or monitoring of P. aeruginosa infections in lower-lung airway infections and other polymicrobial disease contexts.
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23
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Dai J, Huang C, Zhang H, Samuel R, Li Y, Jayaraman A, de Figueiredo P, Han A. Microfluidic Dielectrophoretic Method Enables On-Demand Spatial Arrangement of Bacteria-Encapsulated Agarose Gel Microparticles. Anal Chem 2022; 94:13197-13204. [DOI: 10.1021/acs.analchem.2c02724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jing Dai
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Can Huang
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Han Zhang
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Ryan Samuel
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Yuwen Li
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Arul Jayaraman
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77843, United States
- Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Paul de Figueiredo
- Department of Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas 77807, United States
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas 77843, United States
| | - Arum Han
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, United States
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77843, United States
- Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
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24
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Moffett AS, Thomas PJ, Hinczewski M, Eckford AW. Cheater suppression and stochastic clearance through quorum sensing. PLoS Comput Biol 2022; 18:e1010292. [PMID: 35901008 PMCID: PMC9333318 DOI: 10.1371/journal.pcbi.1010292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 06/09/2022] [Indexed: 11/24/2022] Open
Abstract
The evolutionary consequences of quorum sensing in regulating bacterial cooperation are not fully understood. In this study, we reveal unexpected effects of regulating public good production through quorum sensing on bacterial population dynamics, showing that quorum sensing can be a collectively harmful alternative to unregulated production. We analyze a birth-death model of bacterial population dynamics accounting for public good production and the presence of non-producing cheaters. Our model demonstrates that when demographic noise is a factor, the consequences of controlling public good production according to quorum sensing depend on the cost of public good production and the growth rate of populations in the absence of public goods. When public good production is inexpensive, quorum sensing is a destructive alternative to unconditional production, in terms of the mean population extinction time. When costs are higher, quorum sensing becomes a constructive strategy for the producing strain, both stabilizing cooperation and decreasing the risk of population extinction. Quorum sensing is a process through which bacteria can regulate gene expression according to their population density. The reasons for why bacteria use quorum sensing to regulate production of “public goods”, biochemical products that benefit nearby bacteria, are not entirely clear. We use mathematical modeling to explore how quorum sensing compares to other strategies for controlling production of public goods, namely unconditional production independent on population density, in small populations of bacteria where the random nature of growth is significant. Our model captures both how likely “cheater” strains, which do not produce public goods but benefit from them, are to take over a population and how long on average the population will last before going extinct. We find that depending on how expensive public good production is and how critical public goods are for growth, quorum sensing can decrease or increase the mean time to extinction compared with unconditional production, while always reducing the likelihood of cheaters taking over. Our results could have important implications for the growth of bacterial infections, for example Pseudomonas aeruginosa infections of the lungs of cystic fibrosis patients.
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Affiliation(s)
- Alexander S. Moffett
- Department of Electrical Engineering and Computer Science, York University, Toronto, Ontario, Canada
| | - Peter J. Thomas
- Department of Mathematics, Applied Mathematics, and Statistics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Michael Hinczewski
- Department of Physics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Andrew W. Eckford
- Department of Electrical Engineering and Computer Science, York University, Toronto, Ontario, Canada
- * E-mail:
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25
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Hall KM, Pursell ZF, Morici LA. The role of the Pseudomonas aeruginosa hypermutator phenotype on the shift from acute to chronic virulence during respiratory infection. Front Cell Infect Microbiol 2022; 12:943346. [PMID: 35937684 PMCID: PMC9355025 DOI: 10.3389/fcimb.2022.943346] [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: 05/13/2022] [Accepted: 06/30/2022] [Indexed: 11/13/2022] Open
Abstract
Chronic respiratory infection (CRI) with Pseudomonas aeruginosa (Pa) presents many unique challenges that complicate treatment. One notable challenge is the hypermutator phenotype which is present in up to 60% of sampled CRI patient isolates. Hypermutation can be caused by deactivating mutations in DNA mismatch repair (MMR) genes including mutS, mutL, and uvrD. In vitro and in vivo studies have demonstrated hypermutator strains to be less virulent than wild-type Pa. However, patients colonized with hypermutators display poorer lung function and a higher incidence of treatment failure. Hypermutation and MMR-deficiency create increased genetic diversity and population heterogeneity due to elevated mutation rates. MMR-deficient strains demonstrate higher rates of mucoidy, a hallmark virulence determinant of Pa during CRI in cystic fibrosis patients. The mucoid phenotype results from simple sequence repeat mutations in the mucA gene made in the absence of functional MMR. Mutations in Pa are further increased in the absence of MMR, leading to microcolony biofilm formation, further lineage diversification, and population heterogeneity which enhance bacterial persistence and host immune evasion. Hypermutation facilitates the adaptation to the lung microenvironment, enabling survival among nutritional complexity and microaerobic or anaerobic conditions. Mutations in key acute-to-chronic virulence “switch” genes, such as retS, bfmS, and ampR, are also catalyzed by hypermutation. Consequently, strong positive selection for many loss-of-function pathoadaptive mutations is seen in hypermutators and enriched in genes such as lasR. This results in the characteristic loss of Pa acute infection virulence factors, including quorum sensing, flagellar motility, and type III secretion. Further study of the role of hypermutation on Pa chronic infection is needed to better inform treatment regimens against CRI with hypermutator strains.
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Affiliation(s)
- Kalen M. Hall
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Zachary F. Pursell
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Lisa A. Morici
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States
- *Correspondence: Lisa A. Morici,
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26
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Chen L, Zhao B, Palomo A, Sun Y, Cheng Z, Zhang M, Xia Y. Micron-scale biogeography reveals conservative intra anammox bacteria spatial co-associations. WATER RESEARCH 2022; 220:118640. [PMID: 35661503 DOI: 10.1016/j.watres.2022.118640] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
Micron-scale resolution can help to reliably identify true taxon-taxon interactions in complex microbial communities. Despite widespread recognition of the critical role of metabolic interactions in anaerobic ammonium oxidation (anammox) system performance, no studies have examined microbial interactions at the micron-scale in anammox consortia. To fill this gap, we extensively sampled (totally 242 samples) the consortia of a lab-scale anammox reactor at different length scales, including bulk-scale (∼cm), macro-scale (300-500 µm) and micron-scale (70-100 µm). We firstly observed evident micron-scale heterogeneity in anammox consortia, with the relative abundance of anammox bacteria fluctuated greatly across individual clusters (2.0%-79.3%), indicating that the biotic interactions play a significant role in the assembly of anammox communities under well-controlled and well-mixed condition. Importantly, by mapping the spatial associations in anammox consortia at micron-scale, we demonstrated that the conserved co-associations for anammox bacteria were restricted to three different Brocadia species over time, and their co-associations with heterotrophs were random, implying that there was no statistically significant symbiotic interaction between anammox bacteria and other heterotrophic populations. Further metagenomic binning revealed that the quorum sensing with secondary messenger c-di-GMP potentially holding on the conservative metabolic cooperation among Brocadia species. These results shed new light on the social behavior of the anammox community. Overall, delineating of biological structures at micron-scale opens a new way of monitoring the microbial spatial structure and interactions, paving the way for improved community engineering of biotreatment systems.
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Affiliation(s)
- Liming Chen
- School of Environmental Science and Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Bixi Zhao
- School of Environmental Science and Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Alejandro Palomo
- School of Environmental Science and Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yuhong Sun
- School of Environmental Science and Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhanwen Cheng
- School of Environmental Science and Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Miao Zhang
- School of Environmental Science and Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yu Xia
- School of Environmental Science and Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen 518055, China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
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27
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Abstract
Biofilm formation is an important and ubiquitous mode of growth among bacteria. Central to the evolutionary advantage of biofilm formation is cell-cell and cell-surface adhesion achieved by a variety of factors, some of which are diffusible compounds that may operate as classical public goods-factors that are costly to produce but may benefit other cells. An outstanding question is how diffusible matrix production, in general, can be stable over evolutionary timescales. In this work, using Vibrio cholerae as a model, we show that shared diffusible biofilm matrix proteins are indeed susceptible to cheater exploitation and that the evolutionary stability of producing these matrix components fundamentally depends on biofilm spatial structure, intrinsic sharing mechanisms of these components, and flow conditions in the environment. We further show that exploitation of diffusible adhesion proteins is localized within a well-defined spatial range around cell clusters that produce them. Based on this exploitation range and the spatial distribution of cell clusters, we constructed a model of costly diffusible matrix production and related these length scales to the relatedness coefficient in social evolution theory. Our results show that production of diffusible biofilm matrix components is evolutionarily stable under conditions consistent with natural biofilm habitats and host environments. We expect the mechanisms revealed in this study to be relevant to other secreted factors that operate as cooperative public goods in bacterial communities and the concept of exploitation range and the associated analysis tools to be generally applicable.
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28
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Development of a Versatile, Low-Cost Electrochemical System to Study Biofilm Redox Activity at the Micron Scale. Appl Environ Microbiol 2022; 88:e0043422. [PMID: 35758758 PMCID: PMC9328185 DOI: 10.1128/aem.00434-22] [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] [Indexed: 11/20/2022] Open
Abstract
Spatially resolving chemical landscapes surrounding microbial communities can provide insight into chemical interactions that dictate cellular physiology. Electrochemical techniques provide an attractive option for studying these interactions due to their robustness and high sensitivity. Unfortunately, commercial electrochemical platforms that are capable of measuring chemical activity on the micron scale are often expensive and do not easily perform multiple scanning techniques. Here, we report development of an inexpensive electrochemical system that features a combined micromanipulator and potentiostat component capable of scanning surfaces while measuring molecular concentrations or redox profiles. We validate this experimental platform for biological use with a two-species biofilm model composed of the oral bacterial pathogen Aggregatibacter actinomycetemcomitans and the oral commensal Streptococcus gordonii. We measure consumption of H2O2 by A. actinomycetemcomitans biofilms temporally and spatially, providing new insights into how A. actinomycetemcomitans responds to this S. gordonii-produced metabolite. We advance our platform to spatially measure redox activity above biofilms. Our analysis supports that redox activity surrounding biofilms is species specific, and the region immediately above an S. gordonii biofilm is highly oxidized compared to that above an A. actinomycetemcomitans biofilm. This work provides description and validation of a versatile, quantitative framework for studying bacterial redox-mediated physiology in an integrated and easily adaptable experimental platform. IMPORTANCE Scanning electrochemical probe microscopy methods can provide information of the chemical environment along a spatial surface with micron-scale resolution. These methods often require expensive instruments that perform optimized and highly sensitive niche techniques. Here, we describe a novel system that combines a micromanipulator that scans micron-sized electrodes across the surface of bacterial biofilms and a potentiostat, which performs various electrochemical techniques. This platform allows for spatial measurement of chemical gradients above live bacteria in real time, and as proof of concept, we utilize this setup to map H2O2 detoxification above an oral pathogen biofilm. We increased the versatility of this platform further by mapping redox potentials of biofilms in real time on the micron scale. Together, this system provides a technical framework for studying chemical interactions among microbes.
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Bacterial Quorum Sensing Allows Graded and Bimodal Cellular Responses to Variations in Population Density. mBio 2022; 13:e0074522. [PMID: 35583321 PMCID: PMC9239169 DOI: 10.1128/mbio.00745-22] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Quorum sensing (QS) is a mechanism of cell-cell communication that connects gene expression to environmental conditions (e.g., cell density) in many bacterial species, mediated by diffusible signal molecules. Current functional studies focus on qualitatively distinct QS ON/OFF states. In the context of density sensing, this view led to the adoption of a “quorum” analogy in which populations sense when they are above a sufficient density (i.e., “quorate”) to efficiently turn on cooperative behaviors. This framework overlooks the potential for intermediate, graded responses to shifts in the environment. In this study, we tracked QS-regulated protease (lasB) expression and showed that Pseudomonas aeruginosa can deliver a graded behavioral response to fine-scale variation in population density, on both the population and single-cell scales. On the population scale, we saw a graded response to variation in population density (controlled by culture carrying capacity). On the single-cell scale, we saw significant bimodality at higher densities, with separate OFF and ON subpopulations that responded differentially to changes in density: a static OFF population of cells and increasing intensity of expression among the ON population of cells. Together, these results indicate that QS can tune gene expression to graded environmental change, with no critical cell mass or “quorum” at which behavioral responses are activated on either the individual-cell or population scale. In an infection context, our results indicate there is not a hard threshold separating a quorate “attack” mode from a subquorate “stealth” mode.
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Liu Y, Gloag ES, Hill PJ, Parsek MR, Wozniak DJ. Interbacterial Antagonism Mediated by a Released Polysaccharide. J Bacteriol 2022; 204:e0007622. [PMID: 35446119 PMCID: PMC9112932 DOI: 10.1128/jb.00076-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 04/06/2022] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa and Staphylococcus aureus are two common pathogens causing chronic infections in the lungs of people with cystic fibrosis (CF) and in wounds, suggesting that these two organisms coexist in vivo. However, P. aeruginosa utilizes various mechanisms to antagonize S. aureus when these organisms are grown together in vitro. Here, we suggest a novel role for Psl in antagonizing S. aureus growth. Psl is an exopolysaccharide that exists in both cell-associated and cell-free forms and is important for biofilm formation in P. aeruginosa. When grown in planktonic coculture with a P. aeruginosa psl mutant, S. aureus had increased survival compared to when it was grown with wild-type P. aeruginosa. We found that cell-free Psl was critical for the killing, as purified cell-free Psl was sufficient to kill S. aureus. Transmission electron microscopy of S. aureus treated with Psl revealed disrupted cell envelopes, suggesting that Psl causes S. aureus cell lysis. This was independent of known mechanisms used by P. aeruginosa to antagonize S. aureus. Cell-free Psl could also promote S. aureus killing during growth in in vivo-like conditions. We also found that Psl production in P. aeruginosa CF clinical isolates positively correlated with the ability to kill S. aureus. This could be a result of P. aeruginosa coevolution with S. aureus in CF lungs. In conclusion, this study defines a novel role for P. aeruginosa Psl in killing S. aureus, potentially impacting the coexistence of these two opportunistic pathogens in vivo. IMPORTANCE Pseudomonas aeruginosa and Staphylococcus aureus are two important opportunistic human pathogens commonly coisolated from clinical samples. However, P. aeruginosa can utilize various mechanisms to antagonize S. aureus in vitro. Here, we investigated the interactions between these two organisms and report a novel role for P. aeruginosa exopolysaccharide Psl in killing S. aureus. We found that cell-free Psl could kill S. aureus in vitro, possibly by inducing cell lysis. This was also observed in conditions reflective of in vivo scenarios. In accord with this, Psl production in P. aeruginosa clinical isolates positively correlated with their ability to kill S. aureus. Together, our data suggest a role for Psl in affecting the coexistence of P. aeruginosa and S. aureus in vivo.
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Affiliation(s)
- Yiwei Liu
- Department of Microbiology, Ohio State University, Columbus, Ohio, USA
- Department of Microbial Infection and Immunity, Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Erin S. Gloag
- Department of Microbial Infection and Immunity, Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Preston J. Hill
- Department of Microbial Infection and Immunity, Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Matthew R. Parsek
- Department of Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Daniel J. Wozniak
- Department of Microbiology, Ohio State University, Columbus, Ohio, USA
- Department of Microbial Infection and Immunity, Ohio State University College of Medicine, Columbus, Ohio, USA
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31
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Hills OJ, Yong CW, Scott AJ, Devine DA, Smith J, Chappell HF. Atomic-scale interactions between quorum sensing autoinducer molecules and the mucoid P. aeruginosa exopolysaccharide matrix. Sci Rep 2022; 12:7724. [PMID: 35545629 PMCID: PMC9095684 DOI: 10.1038/s41598-022-11499-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/18/2022] [Indexed: 12/22/2022] Open
Abstract
Mucoid Pseudomonas aeruginosa is a prevalent cystic fibrosis (CF) lung coloniser whose chronicity is associated with the formation of cation cross-linked exopolysaccharide (EPS) matrices, which form a biofilm that acts as a diffusion barrier, sequestering cationic and neutral antimicrobials, and making it extremely resistant to pharmacological challenge. Biofilm chronicity and virulence of the colony is regulated by quorum sensing autoinducers (QSAIs), small signalling metabolites that pass between bacteria, through the biofilm matrix, regulating genetic responses on a population-wide scale. The nature of how these molecules interact with the EPS is poorly understood, despite the fact that they must pass through EPS matrix to reach neighbouring bacteria. Interactions at the atomic-scale between two QSAI molecules, C4-HSL and PQS—both utilised by mucoid P. aeruginosa in the CF lung—and the EPS, have been studied for the first time using a combined molecular dynamics (MD) and density functional theory (DFT) approach. A large-scale, calcium cross-linked, multi-chain EPS molecular model was developed and MD used to sample modes of interaction between QSAI molecules and the EPS that occur at physiological equilibrium. The thermodynamic stability of the QSAI-EPS adducts were calculated using DFT. These simulations provide a thermodynamic rationale for the apparent free movement of C4-HSL, highlight key molecular functionality responsible for EPS binding and, based on its significantly reduced mobility, suggest PQS as a viable target for quorum quenching.
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Affiliation(s)
- Oliver J Hills
- School of Food Science & Nutrition, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
| | - Chin W Yong
- Daresbury Laboratory, Scientific Computing Department, Science and Technology Facilities Council, Keckwick Lane, Daresbury, Warrington, WA4 4AD, UK.,Division of Pharmacy and Optometry, School of Health Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Andrew J Scott
- School of Chemical & Process Engineering, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Deirdre A Devine
- School of Dentistry, University of Leeds, Clarendon Way, Leeds, LS2 9LU, UK
| | - James Smith
- School of Food Science & Nutrition, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Helen F Chappell
- School of Food Science & Nutrition, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
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32
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Suri M, Mohamed Z, Bint E Naser SF, Mao X, Chen P, Daniel S, Hanrath T. Bioelectronic Platform to Investigate Charge Transfer between Photoexcited Quantum Dots and Microbial Outer Membranes. ACS APPLIED MATERIALS & INTERFACES 2022; 14:15799-15810. [PMID: 35344337 DOI: 10.1021/acsami.1c25032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Photosynthetic semiconductor biohybrids (PSBs) convert light energy to chemical energy through photo-driven charge transfer from nanocrystals to microorganisms that perform bioreactions of interest. Initial proof-of-concept PSB studies with an emphasis on enhanced CO2 conversion have been encouraging; however, bringing the broad prospects of PSBs to fruition is contingent on establishing a firm fundamental understanding of underlying interfacial charge transfer processes. We introduce a bioelectronic platform that reduces the complexity of PSBs by focusing explicitly on interactions between colloidal quantum dots (QDs), microbial outer membranes, and native, small-molecule redox mediators. Our model platform employs a standard three-electrode electrochemical cell with supported outer membranes of Pseudomonas aeruginosa, pyocyanin redox mediators, and semiconducting CdSe QDs dispersed in an aqueous electrolyte. We present a comprehensive electrochemical analysis of this platform via electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and chronoamperometry (CA). EIS reveals the formation and electronic properties of supported outer membrane films. CV reveals the electrochemically active surface area of P. aeruginosa outer membranes and that pyocyanin is the sole species that performs redox with these outer membranes under sweeping applied potential. CA demonstrates that photoexcited charge transfer in this system is driven by the reduction of pyocyanin at the QD surface followed by diffusion of reduced pyocyanin through the outer membrane. The broad applicability of this platform across many bacterial species, QD architectures, and controlled environmental conditions affords the possibility to define design principles for future PSB systems to synergistically integrate concurrent advances in genetically engineered organisms and inorganic nanomaterials.
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Affiliation(s)
- Mokshin Suri
- Robert F. Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Zeinab Mohamed
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Samavi Farnush Bint E Naser
- Robert F. Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Xianwen Mao
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Peng Chen
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Susan Daniel
- Robert F. Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Tobias Hanrath
- Robert F. Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
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33
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Biofilm Survival Strategies in Chronic Wounds. Microorganisms 2022; 10:microorganisms10040775. [PMID: 35456825 PMCID: PMC9025119 DOI: 10.3390/microorganisms10040775] [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: 02/28/2022] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 01/22/2023] Open
Abstract
Bacterial biofilms residing in chronic wounds are thought to have numerous survival strategies, making them extremely difficult to eradicate and resulting in long-term infections. However, much of our knowledge regarding biofilm persistence stems from in vitro models and experiments performed in vivo in animal models. While the knowledge obtained from such experiments is highly valuable, its direct translation to the human clinical setting should be undertaken with caution. In this review, we highlight knowledge obtained from human clinical samples in different aspects of biofilm survival strategies. These strategies have been divided into segments of the following attributes: altered transcriptomic profiles, spatial distribution, the production of extracellular polymeric substances, an altered microenvironment, inter-and intra-species interactions, and heterogeneity in the bacterial population. While all these attributes are speculated to contribute to the enhanced persistence of biofilms in chronic wounds, only some of them have been demonstrated to exist in human wounds. Some of the attributes have been observed in other clinical diseases while others have only been observed in vitro. Here, we have strived to clarify the limitations of the current knowledge in regard to this specific topic, without ignoring important in vitro and in vivo observations.
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34
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van Vliet S, Hauert C, Fridberg K, Ackermann M, Dal Co A. Global dynamics of microbial communities emerge from local interaction rules. PLoS Comput Biol 2022; 18:e1009877. [PMID: 35245282 PMCID: PMC8926250 DOI: 10.1371/journal.pcbi.1009877] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 03/16/2022] [Accepted: 01/28/2022] [Indexed: 12/03/2022] Open
Abstract
Most microbes live in spatially structured communities (e.g., biofilms) in which they interact with their neighbors through the local exchange of diffusible molecules. To understand the functioning of these communities, it is essential to uncover how these local interactions shape community-level properties, such as the community composition, spatial arrangement, and growth rate. Here, we present a mathematical framework to derive community-level properties from the molecular mechanisms underlying the cell-cell interactions for systems consisting of two cell types. Our framework consists of two parts: a biophysical model to derive the local interaction rules (i.e. interaction range and strength) from the molecular parameters underlying the cell-cell interactions and a graph based model to derive the equilibrium properties of the community (i.e. composition, spatial arrangement, and growth rate) from these local interaction rules. Our framework shows that key molecular parameters underlying the cell-cell interactions (e.g., the uptake and leakage rates of molecules) determine community-level properties. We apply our model to mutualistic cross-feeding communities and show that spatial structure can be detrimental for these communities. Moreover, our model can qualitatively recapitulate the properties of an experimental microbial community. Our framework can be extended to a variety of systems of two interacting cell types, within and beyond the microbial world, and contributes to our understanding of how community-level properties emerge from microscopic interactions between cells. Microorganisms perform essential processes on our planet. Many of these processes result from interactions between different species growing in spatially structured communities. A central goal is to understand how community processes emerge from such interactions between cells. Here we develop a mathematical framework to derive community-level properties, such as the community composition, growth rate, and spatial organization, from the molecular mechanisms underlying these cell-cell interactions. We focus on mutualistic communities consisting of two cell types that need to interact with each other in order to grow. We derive equations that describe how changes in the molecular parameters of cellular interactions affect individuals’ and community properties. We find that spatial structure has a negative impact on these mutualistic communities: as cells become surrounded by their own type, they have less access to the other cell type with which they need to interact to grow well. We show that our framework can also be applied to other types of microbial communities and potentially to non-microbial systems such as tissues. More generally, this work advances our understanding of how scales are connected in biological systems, both in the microbial world and beyond.
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Affiliation(s)
- Simon van Vliet
- Department of Zoology; University of British Columbia, Vancouver, British Columbia, Canada
- Biozentrum, University of Basel, Basel, Switzerland
- * E-mail: (SvV); (ADC)
| | - Christoph Hauert
- Department of Zoology; University of British Columbia, Vancouver, British Columbia, Canada
- Department of Mathematics; University of British Columbia, Vancouver, British Columbia, Canada
| | - Kyle Fridberg
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America
| | - Martin Ackermann
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
- Department of Environmental Microbiology, Eawag, Duebendorf, Switzerland
| | - Alma Dal Co
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
- Department of Environmental Microbiology, Eawag, Duebendorf, Switzerland
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
- * E-mail: (SvV); (ADC)
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35
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Azimi S, Lewin GR, Whiteley M. The biogeography of infection revisited. Nat Rev Microbiol 2022; 20:579-592. [PMID: 35136217 PMCID: PMC9357866 DOI: 10.1038/s41579-022-00683-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2022] [Indexed: 01/01/2023]
Abstract
Many microbial communities, including those involved in chronic human infections, are patterned at the micron scale. In this Review, we summarize recent work that has defined the spatial arrangement of microorganisms in infection and begun to demonstrate how changes in spatial patterning correlate with disease. Advances in microscopy have refined our understanding of microbial micron-scale biogeography in samples from humans. These findings then serve as a benchmark for studying the role of spatial patterning in preclinical models, which provide experimental versatility to investigate the interplay between biogeography and pathogenesis. Experimentation using preclinical models has begun to show how spatial patterning influences the interactions between cells, their ability to coexist, their virulence and their recalcitrance to treatment. Future work to study the role of biogeography in infection and the functional biogeography of microorganisms will further refine our understanding of the interplay of spatial patterning, pathogen virulence and disease outcomes.
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Affiliation(s)
- Sheyda Azimi
- School of Biological Sciences and Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA, USA
| | - Gina R Lewin
- Emory-Children's Cystic Fibrosis Center, Atlanta, GA, USA
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36
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Spatial-temporal dynamics of a microbial cooperative behavior resistant to cheating. Nat Commun 2022; 13:721. [PMID: 35132084 PMCID: PMC8821651 DOI: 10.1038/s41467-022-28321-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 01/13/2022] [Indexed: 11/17/2022] Open
Abstract
Much of our understanding of bacterial behavior stems from studies in liquid culture. In nature, however, bacteria frequently live in densely packed spatially-structured communities. How does spatial structure affect bacterial cooperative behaviors? In this work, we examine rhamnolipid production—a cooperative and virulent behavior of Pseudomonas aeruginosa. Here we show that, in striking contrast to well-mixed liquid culture, rhamnolipid gene expression in spatially-structured colonies is strongly associated with colony specific growth rate, and is impacted by perturbation with diffusible quorum signals. To interpret these findings, we construct a data-driven statistical inference model which captures a length-scale of bacterial interaction that develops over time. Finally, we find that perturbation of P. aeruginosa swarms with quorum signals preserves the cooperating genotype in competition, rather than creating opportunities for cheaters. Overall, our data demonstrate that the complex response to spatial localization is key to preserving bacterial cooperative behaviors. Bacteria often live in densely packed, spatially-structured communities; however, much of our understanding of their behavior stems from studies in liquid culture. Here, Monaco et al. show how spatial structure and quorum sensing modulate a cooperative behavior in colonies of Pseudomonas aeruginosa.
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37
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Lichtenberg M, Jakobsen TH, Kühl M, Kolpen M, Jensen PØ, Bjarnsholt T. OUP accepted manuscript. FEMS Microbiol Rev 2022; 46:6574409. [PMID: 35472245 PMCID: PMC9438473 DOI: 10.1093/femsre/fuac018] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 04/04/2022] [Accepted: 04/24/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, København, Denmark
| | - Tim Holm Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, København, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark
| | - Mette Kolpen
- Department of Clinical Microbiology, Copenhagen University Hospital, Ole Maaløes vej 26, 2200, København, Denmark
| | - Peter Østrup Jensen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, København, Denmark
- Department of Clinical Microbiology, Copenhagen University Hospital, Ole Maaløes vej 26, 2200, København, Denmark
| | - Thomas Bjarnsholt
- Corresponding author: Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, København, Denmark. Tel: +45 20659888; E-mail:
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Metabolomic profiling of Burkholderia cenocepacia in synthetic cystic fibrosis sputum medium reveals nutrient environment-specific production of virulence factors. Sci Rep 2021; 11:21419. [PMID: 34725378 PMCID: PMC8560942 DOI: 10.1038/s41598-021-00421-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/12/2021] [Indexed: 12/13/2022] Open
Abstract
Infections by Burkholderia cenocepacia lead to life-threatening disease in immunocompromised individuals, including those living with cystic fibrosis (CF). While genetic variation in various B. cenocepacia strains has been reported, it remains unclear how the chemical environment of CF lung influences the production of small molecule virulence factors by these strains. Here we compare metabolomes of three clinical B. cenocepacia strains in synthetic CF sputum medium (SCFM2) and in a routine laboratory medium (LB), in the presence and absence of the antibiotic trimethoprim. Using a mass spectrometry-based untargeted metabolomics approach, we identify several compound classes which are differentially produced in SCFM2 compared to LB media, including siderophores, antimicrobials, quorum sensing signals, and various lipids. Furthermore, we describe that specific metabolites are induced in the presence of the antibiotic trimethoprim only in SCFM2 when compared to LB. Herein, C13-acyl-homoserine lactone, a quorum sensing signal previously not known to be produced by B. cenocepacia as well as pyochelin-type siderophores were exclusively detected during growth in SCFM2 in the presence of trimethoprim. The comparative metabolomics approach described in this study provides insight into environment-dependent production of secondary metabolites by B. cenocepacia strains and suggests future work which could identify personalized strain-specific regulatory mechanisms involved in production of secondary metabolites. Investigations into whether antibiotics with different mechanisms of action induce similar metabolic alterations will inform development of combination treatments aimed at effective clearance of Burkholderia spp. pathogens.
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Periodically Disturbing the Spatial Structure of Biofilms Can Affect the Production of an Essential Virulence Factor in Pseudomonas aeruginosa. mSystems 2021; 6:e0096121. [PMID: 34581603 PMCID: PMC8547473 DOI: 10.1128/msystems.00961-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Understanding the environmental factors that affect the production of virulence factors has major implications in evolution and medicine. While spatial structure is important in virulence factor production, observations of this relationship have occurred in undisturbed or continuously disturbed environments. However, natural environments are subject to periodic fluctuations, including changes in physical forces, which could alter the spatial structure of bacterial populations and impact virulence factor production. Using Pseudomonas aeruginosa PA14, we periodically applied a physical force to biofilms and examined production of pyoverdine. Intermediate frequencies of disturbance reduced the amount of pyoverdine produced compared to undisturbed or frequently disturbed conditions. To explore the generality of this finding, we examined how an intermediate disturbance frequency affected pyoverdine production in 21 different strains of P. aeruginosa. Periodic disturbance increased, decreased, or did not change the amount of pyoverdine produced relative to undisturbed populations. Mathematical modeling predicts that interactions between pyoverdine synthesis rate and biofilm density determine the amount of pyoverdine synthesized. When the pyoverdine synthesis rates are high, depletion of the biofilm due to disturbance reduces the accumulation of pyoverdine. At intermediate synthesis rates, production of pyoverdine increases during disturbance as bacteria dispersed into the planktonic state enjoy increased growth and pyoverdine production rates. At low synthesis rates, disturbance does not alter the amount of pyoverdine produced since disturbance-driven access to nutrients does not augment pyoverdine synthesis. Our results suggest that environmental conditions shape robustness in the production of virulence factors and may lead to novel approaches to treat infections. IMPORTANCE Virulence factors are required to cause infections. Previous work has shown that the spatial organization of a population, such as a biofilm, can increase the production of some virulence factors, including pyoverdine, which is produced by Pseudomonas aeruginosa. Pyoverdine is essential for the infection process, and reducing its production can limit infections. We have discovered that periodically changing the spatial structure of a biofilm of P. aeruginosa strain PA14 using a physical force can reduce the production of pyoverdine. A mathematical model suggests that this is due to the disruption of spatial organization. Using additional strains of P. aeruginosa isolated from patients and the environment, we use experiments and modeling to show that this reduction in pyoverdine is due to interactions between biofilm density and the synthesis rate of pyoverdine. Our results identify conditions where pyoverdine production is reduced and may lead to novel ways to treat infections.
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40
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Armbruster CR, Marshall CW, Garber AI, Melvin JA, Zemke AC, Moore J, Zamora PF, Li K, Fritz IL, Manko CD, Weaver ML, Gaston JR, Morris A, Methé B, DePas WH, Lee SE, Cooper VS, Bomberger JM. Adaptation and genomic erosion in fragmented Pseudomonas aeruginosa populations in the sinuses of people with cystic fibrosis. Cell Rep 2021; 37:109829. [PMID: 34686349 PMCID: PMC8667756 DOI: 10.1016/j.celrep.2021.109829] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/09/2021] [Accepted: 09/22/2021] [Indexed: 10/20/2022] Open
Abstract
Pseudomonas aeruginosa notoriously adapts to the airways of people with cystic fibrosis (CF), yet how infection-site biogeography and associated evolutionary processes vary as lifelong infections progress remains unclear. Here we test the hypothesis that early adaptations promoting aggregation influence evolutionary-genetic trajectories by examining longitudinal P. aeruginosa from the sinuses of six adults with CF. Highly host-adapted lineages harbored mutator genotypes displaying signatures of early genome degradation associated with recent host restriction. Using an advanced imaging technique (MiPACT-HCR [microbial identification after passive clarity technique]), we find population structure tracks with genome degradation, with the most host-adapted, genome-degraded P. aeruginosa (the mutators) residing in small, sparse aggregates. We propose that following initial adaptive evolution in larger populations under strong selection for aggregation, P. aeruginosa persists in small, fragmented populations that experience stronger effects of genetic drift. These conditions enrich for mutators and promote degenerative genome evolution. Our findings underscore the importance of infection-site biogeography to pathogen evolution.
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Affiliation(s)
- Catherine R Armbruster
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | | | - Arkadiy I Garber
- Biodesign Center for Mechanisms of Evolution and School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
| | - Jeffrey A Melvin
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Anna C Zemke
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - John Moore
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Paula F Zamora
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Kelvin Li
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Ian L Fritz
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Christopher D Manko
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Madison L Weaver
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Jordan R Gaston
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Alison Morris
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Barbara Methé
- Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - William H DePas
- Department of Pediatrics, Children's Hospital of Pittsburgh and University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Stella E Lee
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA.
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA; Center for Medicine and the Microbiome, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA; Pittsburgh Center for Evolutionary Biology & Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
| | - Jennifer M Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
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Impact of artificial sputum media formulation on Pseudomonas aeruginosa secondary metabolite production. J Bacteriol 2021; 203:e0025021. [PMID: 34398662 PMCID: PMC8508215 DOI: 10.1128/jb.00250-21] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
In vitro culture media are being developed to understand how host site-specific nutrient profiles influence microbial pathogenicity and ecology. To mimic the cystic fibrosis (CF) lung environment, a variety of artificial sputum media (ASM) have been created. However, the composition of these ASM vary in the concentration of key nutrients, including amino acids, lipids, DNA, and mucin. In this work, we used feature-based molecular networking (FBMN) to perform comparative metabolomics of Pseudomonas aeruginosa, the predominant opportunistic pathogen infecting the lungs of people with CF, cultured in nine different ASM. We found that the concentration of aromatic amino acids and iron from mucin added to the media contributes to differences in the production of P. aeruginosa virulence-associated secondary metabolites. IMPORTANCE Different media formulations aiming to replicate in vivo infection environments contain different nutrients, which affects interpretation of experimental results. Inclusion of undefined components, such as commercial porcine gastric mucin (PGM), in an otherwise chemically defined medium can alter the nutrient content of the medium in unexpected ways and influence experimental outcomes.
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42
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Xu Y, Yang S, You G, Hou J. Attenuation effects of iron on dissemination of antibiotic resistance genes in anaerobic bioreactor: Evolution of quorum sensing, quorum quenching and dynamics of community composition. JOURNAL OF HAZARDOUS MATERIALS 2021; 416:126136. [PMID: 34492925 DOI: 10.1016/j.jhazmat.2021.126136] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 04/02/2021] [Accepted: 05/13/2021] [Indexed: 06/13/2023]
Abstract
Zero valent iron (ZVI) coupled with bioreactors is arising as a promising technology for antibiotic resistance genes (ARGs) mitigation, whereas the succession and behaviors of microbes caused by ZVI in relieving ARGs propagation remain unclear. Herein, the effects of ZVI on microbial quorum sensing (QS), quorum quenching (QQ) system and community dynamics were examined in anaerobic bioreactor fed with oxytetracycline (tet), to illustrate the roles of evolutive microbial communication and community composition in ARGs attenuation. With the addition of 5 g/L ZVI, the total absolute abundance of tet ARGs was retarded by approximate 95% and 72% in sludge and effluent after 25 days operation. The abundance of mobile genetic elements and the heredity of antibiotic resistant bacteria revealed the declined horizontal and vertical transfer of ARGs, which directly led to the reduced ARGs propagation. Potential mechanisms are that the positive effects of ZVI on QQ activity via the functional bacteria enrichment inhibited QS system and thus ARGs transfer. Partial least--squares path modeling further demonstrated that ARGs abundance was strongly limited by the dynamics of bacterial composition and thereby less frequent microbial communication. These results provide new insights into the mechanisms of antibiotic resistome remission in anaerobic bioreactor modified by ZVI.
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Affiliation(s)
- Yi Xu
- College of Agricultural Science and Engineering, Hohai University, Nanjing 210098, People's Republic of China; Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, People's Republic of China
| | - Shihong Yang
- College of Agricultural Science and Engineering, Hohai University, Nanjing 210098, People's Republic of China
| | - Guoxiang You
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, People's Republic of China
| | - Jun Hou
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, People's Republic of China.
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O-Specific Antigen-Dependent Surface Hydrophobicity Mediates Aggregate Assembly Type in Pseudomonas aeruginosa. mBio 2021; 12:e0086021. [PMID: 34372703 PMCID: PMC8406328 DOI: 10.1128/mbio.00860-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Bacteria live in spatially organized aggregates during chronic infections, where they adapt to the host environment, evade immune responses, and resist therapeutic interventions. Although it is known that environmental factors such as polymers influence bacterial aggregation, it is not clear how bacterial adaptation during chronic infection impacts the formation and spatial organization of aggregates in the presence of polymers. Here, we show that in an in vitro model of cystic fibrosis (CF) containing the polymers extracellular DNA (eDNA) and mucin, O-specific antigen is a major factor determining the formation of two distinct aggregate assembly types of Pseudomonas aeruginosa due to alterations in cell surface hydrophobicity. Our findings suggest that during chronic infection, the interplay between cell surface properties and polymers in the environment may influence the formation and structure of bacterial aggregates, which would shed new light on the fitness costs and benefits of O-antigen production in environments such as CF lungs.
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Both Pseudomonas aeruginosa and Candida albicans Accumulate Greater Biomass in Dual-Species Biofilms under Flow. mSphere 2021; 6:e0041621. [PMID: 34160236 PMCID: PMC8265656 DOI: 10.1128/msphere.00416-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Microbe-microbe interactions can strongly influence growth and biofilm formation kinetics. For Pseudomonas aeruginosa and Candida albicans, which are found together in diverse clinical sites, including urinary and intravenous catheters and the lungs of individuals with cystic fibrosis (CF), we compared the kinetics of biofilm formation by each species in dual-species and single-species biofilms. We engineered fluorescent protein constructs for P. aeruginosa (producing mKO-κ) and C. albicans (producing mKate2) that did not alter growth and enabled single-cell resolution imaging by live-sample microscopy. Using these strains in an optically clear derivative of synthetic CF sputum medium, we found that both P. aeruginosa and C. albicans displayed increased biovolume accumulation—by three- and sixfold, respectively—in dual-species biofilms relative to single-species biofilms. This result was specific to the biofilm environment, as enhanced growth was not observed in planktonic cocultures. Stimulation of C. albicans biofilm formation occurred regardless of whether P. aeruginosa was added at the time of fungal inoculation or 24 h after the initiation of biofilm development. P. aeruginosa biofilm increases in cocultures did not require the Pel extracellular polysaccharide, phenazines, and siderophores known to influence C. albicans. P. aeruginosa mutants lacking Anr, LasR, and BapA were not significantly stimulated by C. albicans, but they still promoted a significant enhancement of biofilm development of the fungus, suggesting a fungal response to the presence of bacteria. Last, we showed that a set of P. aeruginosa clinical isolates also prompted an increase of biovolume by C. albicans in coculture. IMPORTANCE There is an abundance of work on both P. aeruginosa and C. albicans in isolation, and quite some work as well on the way these two microbes interact. These studies do not, however, consider biofilm environments under flow, and our results here show that the expected outcome of interaction between these two pathogens can actually be reversed under flow, from pure antagonism to an increase in biomass on the part of both. Our work also highlights the importance of cellular-scale spatial structure in biofilms for understanding multispecies population dynamics.
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45
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Mucin O-glycans suppress quorum-sensing pathways and genetic transformation in Streptococcus mutans. Nat Microbiol 2021; 6:574-583. [PMID: 33737747 PMCID: PMC8811953 DOI: 10.1038/s41564-021-00876-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 02/03/2021] [Indexed: 01/31/2023]
Abstract
Mucus barriers accommodate trillions of microorganisms throughout the human body while preventing pathogenic colonization1. In the oral cavity, saliva containing the mucins MUC5B and MUC7 forms a pellicle that coats the soft tissue and teeth to prevent infection by oral pathogens, such as Streptococcus mutans2. Salivary mucin can interact directly with microorganisms through selective agglutinin activity and bacterial binding2-4, but the extent and basis of the protective functions of saliva are not well understood. Here, using an ex vivo saliva model, we identify that MUC5B is an inhibitor of microbial virulence. Specifically, we find that natively purified MUC5B downregulates the expression of quorum-sensing pathways activated by the competence stimulating peptide and the sigX-inducing peptide5. Furthermore, MUC5B prevents the acquisition of antimicrobial resistance through natural genetic transformation, a process that is activated through quorum sensing. Our data reveal that the effect of MUC5B is mediated by its associated O-linked glycans, which are potent suppressors of quorum sensing and genetic transformation, even when removed from the mucin backbone. Together, these results present mucin O-glycans as a host strategy for domesticating potentially pathogenic microorganisms without killing them.
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46
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van Gestel J, Bareia T, Tenennbaum B, Dal Co A, Guler P, Aframian N, Puyesky S, Grinberg I, D’Souza GG, Erez Z, Ackermann M, Eldar A. Short-range quorum sensing controls horizontal gene transfer at micron scale in bacterial communities. Nat Commun 2021; 12:2324. [PMID: 33875666 PMCID: PMC8055654 DOI: 10.1038/s41467-021-22649-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 03/17/2021] [Indexed: 02/02/2023] Open
Abstract
In bacterial communities, cells often communicate by the release and detection of small diffusible molecules, a process termed quorum-sensing. Signal molecules are thought to broadly diffuse in space; however, they often regulate traits such as conjugative transfer that strictly depend on the local community composition. This raises the question how nearby cells within the community can be detected. Here, we compare the range of communication of different quorum-sensing systems. While some systems support long-range communication, we show that others support a form of highly localized communication. In these systems, signal molecules propagate no more than a few microns away from signaling cells, due to the irreversible uptake of the signal molecules from the environment. This enables cells to accurately detect micron scale changes in the community composition. Several mobile genetic elements, including conjugative elements and phages, employ short-range communication to assess the fraction of susceptible host cells in their vicinity and adaptively trigger horizontal gene transfer in response. Our results underscore the complex spatial biology of bacteria, which can communicate and interact at widely different spatial scales.
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Affiliation(s)
- Jordi van Gestel
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland ,grid.418656.80000 0001 1551 0562Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland ,grid.7400.30000 0004 1937 0650Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland ,grid.419765.80000 0001 2223 3006Swiss Institute of Bioinformatics, Lausanne, Switzerland ,grid.266102.10000 0001 2297 6811Present Address: Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA USA
| | - Tasneem Bareia
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Bar Tenennbaum
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Alma Dal Co
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland ,grid.418656.80000 0001 1551 0562Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland ,grid.38142.3c000000041936754XSchool of Engineering and Applied Sciences, Harvard University, Cambridge, MA USA
| | - Polina Guler
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Nitzan Aframian
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Shani Puyesky
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Ilana Grinberg
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Glen G. D’Souza
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland ,grid.418656.80000 0001 1551 0562Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland
| | - Zohar Erez
- grid.13992.300000 0004 0604 7563Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Martin Ackermann
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland ,grid.418656.80000 0001 1551 0562Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland
| | - Avigdor Eldar
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
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47
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A Pseudomonas aeruginosa Antimicrobial Affects the Biogeography but Not Fitness of Staphylococcus aureus during Coculture. mBio 2021; 12:mBio.00047-21. [PMID: 33785630 PMCID: PMC8092195 DOI: 10.1128/mbio.00047-21] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Many human infections result from the action of multispecies bacterial communities. Within these communities, bacteria have been proposed to directly interact via physical and chemical means, resulting in increased disease and antimicrobial tolerance. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most common coinfecting bacteria in human infections, including the cystic fibrosis (CF) lung. There is emerging evidence that coinfection with these microbes enhances disease severity and antimicrobial tolerance through direct interactions. However, one of the challenges to studying microbial interactions relevant to human infection is the lack of experimental models with the versatility to investigate complex interaction dynamics while maintaining biological relevance. Here, we developed a model based on an in vitro medium that mimics human CF lung secretions (synthetic CF sputum medium [SCFM2]) and allows time-resolved assessment of fitness and community spatial structure at the micrometer scale. Our results reveal that P. aeruginosa and S. aureus coexist as spatially structured communities in SCFM2 under static growth conditions, with S. aureus enriched at a distance of 3.5 μm from P. aeruginosa. Multispecies aggregates were rare, and aggregate (biofilm) sizes resembled those in human CF sputum. Elimination of P. aeruginosa’s ability to produce the antistaphylococcal small molecule HQNO (2-heptyl-4-hydroxyquinoline N-oxide) had no effect on bacterial fitness but altered the spatial structure of the community by increasing the distance of S. aureus from P. aeruginosa to 7.6 μm. Lastly, we show that coculture with P. aeruginosa sensitizes S. aureus to killing by the antibiotic tobramycin compared to monoculture growth despite HQNO enhancing tolerance during coculture. Our findings reveal that SCFM2 is a powerful model for studying P. aeruginosa and S. aureus and that HQNO alters S. aureus biogeography and antibiotic susceptibility without affecting fitness.
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48
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Wang BX, Wu CM, Ribbeck K. Home, sweet home: how mucus accommodates our microbiota. FEBS J 2021; 288:1789-1799. [PMID: 32755014 PMCID: PMC8739745 DOI: 10.1111/febs.15504] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 07/17/2020] [Accepted: 07/30/2020] [Indexed: 12/16/2022]
Abstract
As a natural environment for human-microbiota interactions, healthy mucus houses a remarkably stable and diverse microbial community. Maintaining this microbiota is essential to human health, both to support the commensal bacteria that perform a wide array of beneficial functions and to prevent the outgrowth of pathogens. However, how the host selects and maintains a specialized microbiota remains largely unknown. In this viewpoint, we propose several strategies by which mucus may regulate the composition and function of the human microbiota and discuss how compromised mucus barriers in disease can give rise to microbial dysbiosis.
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Affiliation(s)
- Benjamin X Wang
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Microbiology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Chloe M Wu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Katharina Ribbeck
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
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49
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Jean-Pierre F, Henson MA, O’Toole GA. Metabolic Modeling to Interrogate Microbial Disease: A Tale for Experimentalists. Front Mol Biosci 2021; 8:634479. [PMID: 33681294 PMCID: PMC7930556 DOI: 10.3389/fmolb.2021.634479] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 01/19/2021] [Indexed: 12/14/2022] Open
Abstract
The explosion of microbiome analyses has helped identify individual microorganisms and microbial communities driving human health and disease, but how these communities function is still an open question. For example, the role for the incredibly complex metabolic interactions among microbial species cannot easily be resolved by current experimental approaches such as 16S rRNA gene sequencing, metagenomics and/or metabolomics. Resolving such metabolic interactions is particularly challenging in the context of polymicrobial communities where metabolite exchange has been reported to impact key bacterial traits such as virulence and antibiotic treatment efficacy. As novel approaches are needed to pinpoint microbial determinants responsible for impacting community function in the context of human health and to facilitate the development of novel anti-infective and antimicrobial drugs, here we review, from the viewpoint of experimentalists, the latest advances in metabolic modeling, a computational method capable of predicting metabolic capabilities and interactions from individual microorganisms to complex ecological systems. We use selected examples from the literature to illustrate how metabolic modeling has been utilized, in combination with experiments, to better understand microbial community function. Finally, we propose how such combined, cross-disciplinary efforts can be utilized to drive laboratory work and drug discovery moving forward.
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Affiliation(s)
- Fabrice Jean-Pierre
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Michael A. Henson
- Department of Chemical Engineering and Institute for Applied Life Sciences, University of Massachusetts, Amherst, MA, United States
| | - George A. O’Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
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50
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Short B, Carson S, Devlin AC, Reihill JA, Crilly A, MacKay W, Ramage G, Williams C, Lundy FT, McGarvey LP, Thornbury KD, Martin SL. Non-typeable Haemophilus influenzae chronic colonization in chronic obstructive pulmonary disease (COPD). Crit Rev Microbiol 2021; 47:192-205. [PMID: 33455514 DOI: 10.1080/1040841x.2020.1863330] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Haemophilus influenzae is the most common cause of bacterial infection in the lungs of chronic obstructive pulmonary disease (COPD) patients and contributes to episodes of acute exacerbation which are associated with increased hospitalization and mortality. Due to the ability of H. influenzae to adhere to host epithelial cells, initial colonization of the lower airways can progress to a persistent infection and biofilm formation. This is characterized by changes in bacterial behaviour such as reduced cellular metabolism and the production of an obstructive extracellular matrix (ECM). Herein we discuss the multiple mechanisms by which H. influenzae contributes to the pathogenesis of COPD. In particular, mechanisms that facilitate bacterial adherence to host airway epithelial cells, biofilm formation, and microbial persistence through immune system evasion and antibiotic tolerance will be discussed.
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Affiliation(s)
- Bryn Short
- University of the West of Scotland, Paisley, United Kingdom
| | - Stephen Carson
- School of Pharmacy, Queen's University Belfast, Belfast, United Kingdom
| | - Anna-Claire Devlin
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - James A Reihill
- School of Pharmacy, Queen's University Belfast, Belfast, United Kingdom
| | - Anne Crilly
- University of the West of Scotland, Paisley, United Kingdom
| | - William MacKay
- University of the West of Scotland, Paisley, United Kingdom
| | - Gordon Ramage
- Glasgow Biofilm Research Group, Oral Sciences, School of Medicine, Dentistry and Nursing, University of Glasgow, Glasgow, United Kingdom
| | - Craig Williams
- University of the West of Scotland, Paisley, United Kingdom
| | - Fionnuala T Lundy
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Lorcan P McGarvey
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Keith D Thornbury
- Smooth Muscle Research Group, Dundalk Institute of Technology, Dundalk, Ireland
| | - S Lorraine Martin
- School of Pharmacy, Queen's University Belfast, Belfast, United Kingdom
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