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Santos-Júnior CD, Torres MDT, Duan Y, Rodríguez Del Río Á, Schmidt TSB, Chong H, Fullam A, Kuhn M, Zhu C, Houseman A, Somborski J, Vines A, Zhao XM, Bork P, Huerta-Cepas J, de la Fuente-Nunez C, Coelho LP. Discovery of antimicrobial peptides in the global microbiome with machine learning. Cell 2024; 187:3761-3778.e16. [PMID: 38843834 DOI: 10.1016/j.cell.2024.05.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 04/11/2024] [Accepted: 05/06/2024] [Indexed: 06/25/2024]
Abstract
Novel antibiotics are urgently needed to combat the antibiotic-resistance crisis. We present a machine-learning-based approach to predict antimicrobial peptides (AMPs) within the global microbiome and leverage a vast dataset of 63,410 metagenomes and 87,920 prokaryotic genomes from environmental and host-associated habitats to create the AMPSphere, a comprehensive catalog comprising 863,498 non-redundant peptides, few of which match existing databases. AMPSphere provides insights into the evolutionary origins of peptides, including by duplication or gene truncation of longer sequences, and we observed that AMP production varies by habitat. To validate our predictions, we synthesized and tested 100 AMPs against clinically relevant drug-resistant pathogens and human gut commensals both in vitro and in vivo. A total of 79 peptides were active, with 63 targeting pathogens. These active AMPs exhibited antibacterial activity by disrupting bacterial membranes. In conclusion, our approach identified nearly one million prokaryotic AMP sequences, an open-access resource for antibiotic discovery.
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Affiliation(s)
- Célio Dias Santos-Júnior
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai 200433, China; Laboratory of Microbial Processes & Biodiversity - LMPB, Department of Hydrobiology, Universidade Federal de São Carlos - UFSCar, São Carlos, São Paulo 13565-905, Brazil
| | - Marcelo D T Torres
- Machine Biology Group, Departments of Psychiatry and Microbiology, Institute for Biomedical Informatics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Departments of Bioengineering and Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA; Penn Institute for Computational Science, University of Pennsylvania, Philadelphia, PA, USA
| | - Yiqian Duan
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai 200433, China
| | - Álvaro Rodríguez Del Río
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Campus de Montegancedo-UPM, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Thomas S B Schmidt
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany; APC Microbiome & School of Medicine, University College Cork, Cork, Ireland
| | - Hui Chong
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai 200433, China
| | - Anthony Fullam
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Michael Kuhn
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Chengkai Zhu
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai 200433, China
| | - Amy Houseman
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai 200433, China
| | - Jelena Somborski
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai 200433, China
| | - Anna Vines
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai 200433, China
| | - Xing-Ming Zhao
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai 200433, China; Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, China; State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, China; MOE Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Peer Bork
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany; Max Delbrück Centre for Molecular Medicine, Berlin, Germany; Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jaime Huerta-Cepas
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Campus de Montegancedo-UPM, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Cesar de la Fuente-Nunez
- Machine Biology Group, Departments of Psychiatry and Microbiology, Institute for Biomedical Informatics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Departments of Bioengineering and Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA; Penn Institute for Computational Science, University of Pennsylvania, Philadelphia, PA, USA.
| | - Luis Pedro Coelho
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai 200433, China; Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology, Translational Research Institute, Woolloongabba, QLD, Australia.
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2
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Virgo M, Mostowy S, Ho BT. Use of zebrafish to identify host responses specific to type VI secretion system mediated interbacterial antagonism. PLoS Pathog 2024; 20:e1012384. [PMID: 39024393 DOI: 10.1371/journal.ppat.1012384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 07/30/2024] [Accepted: 07/01/2024] [Indexed: 07/20/2024] Open
Abstract
Interbacterial competition is known to shape the microbial communities found in the host, however the interplay between this competition and host defense are less clear. Here, we use the zebrafish hindbrain ventricle (HBV) as an in vivo platform to investigate host responses to defined bacterial communities with distinct forms of interbacterial competition. We found that antibacterial activity of the type VI secretion system (T6SS) from both Vibrio cholerae and Acinetobacter baylyi can induce host inflammation and sensitize the host to infection independent of any individual effector. Chemical suppression of inflammation could resolve T6SS-dependent differences in host survival, but the mechanism by which this occurred differed between the two bacterial species. By contrast, colicin-mediated antagonism elicited by an avirulent strain of Shigella sonnei induced a negligible host response despite being a more potent bacterial killer, resulting in no impact on A. baylyi or V. cholerae virulence. Altogether, these results provide insight into how different modes of interbacterial competition in vivo affect the host in distinct ways.
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Affiliation(s)
- Mollie Virgo
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, London, United Kingdom
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
| | - Serge Mostowy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
| | - Brian T Ho
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, London, United Kingdom
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
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3
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Yang L, Jia S, Sun S, Wang L, Zhao B, Zhang M, Yin Y, Yang M, Fulano AM, Shen X, Pan J, Wang Y. A pyocin-like T6SS effector mediates bacterial competition in Yersinia pseudotuberculosis. Microbiol Spectr 2024; 12:e0427823. [PMID: 38712967 DOI: 10.1128/spectrum.04278-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/18/2024] [Indexed: 05/08/2024] Open
Abstract
Within the realm of Gram-negative bacteria, bacteriocins are secreted almost everywhere, and the most representative are colicin and pyocin, which are secreted by Escherichia coli and Pseudomonas aeruginosa, respectively. Signal peptides at the amino terminus of bacteriocins or ABC transporters can secrete bacteriocins, which then enter bacteria through cell membrane receptors and exert toxicity. In general, the bactericidal spectrum is usually narrow, killing only the kin or closely related species. Our previous research indicates that YPK_0952 is an effector of the third Type VI secretion system (T6SS-3) in Yersinia pseudotuberculosis. Next, we sought to determine its identity and characterize its toxicity. We found that YPK_0952 (a pyocin-like effector) can achieve intra-species and inter-species competitive advantages through both contact-dependent and contact-independent mechanisms mediated by the T6SS-3 while enhancing the intestinal colonization capacity of Y. pseudotuberculosis. We further identified YPK_0952 as a DNase dependent on Mg2+, Ni2+, Mn2+, and Co2+ bivalent metal ions, and the homologous immune protein YPK_0953 can inhibit its activity. In summary, YPK_0952 exerts toxicity by degrading nucleic acids from competing cells, and YPK_0953 prevents self-attack in Y. pseudotuberculosis.IMPORTANCEBacteriocins secreted by Gram-negative bacteria generally enter cells through specific interactions on the cell surface, resulting in a narrow bactericidal spectrum. First, we identified a new pyocin-like effector protein, YPK_0952, in the third Type VI secretion system (T6SS-3) of Yersinia pseudotuberculosis. YPK_0952 is secreted by T6SS-3 and can exert DNase activity through contact-dependent and contact-independent entry into nearby cells of the same and other species (e.g., Escherichia coli) to help Y. pseudotuberculosis to exert a competitive advantage and promote intestinal colonization. This discovery lays the foundation for an in-depth study of the different effector protein types within the T6SS and their complexity in competing interactions. At the same time, this study provides a new development for the toolbox of toxin/immune pairs for studying Gram-negative bacteriocin translocation.
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Affiliation(s)
- Leilei Yang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Shuangkai Jia
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Sihuai Sun
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Lei Wang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Bobo Zhao
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Mengsi Zhang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Yanling Yin
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
- College of Life Sciences, Tarim University, Alar, Xinjiang, China
| | - Mingming Yang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Alex M Fulano
- Department of Plant Science and Crop Protection, University of Nairobi, Nairobi, Kenya
| | - Xihui Shen
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
- College of Life Sciences, Tarim University, Alar, Xinjiang, China
| | - Junfeng Pan
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Yao Wang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
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4
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Miles SL, Holt KE, Mostowy S. Recent advances in modelling Shigella infection. Trends Microbiol 2024:S0966-842X(24)00044-1. [PMID: 38423917 DOI: 10.1016/j.tim.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/06/2024] [Accepted: 02/06/2024] [Indexed: 03/02/2024]
Abstract
Shigella is an important human-adapted pathogen which contributes to a large global burden of diarrhoeal disease. Together with the increasing threat of antimicrobial resistance and lack of an effective vaccine, there is great urgency to identify novel therapeutics and preventatives to combat Shigella infection. In this review, we discuss the development of innovative technologies and animal models to study mechanisms underlying Shigella infection of humans. We examine recent literature introducing (i) the organ-on-chip model, and its substantial contribution towards understanding the biomechanics of Shigella infection, (ii) the zebrafish infection model, which has delivered transformative insights into the epidemiological success of clinical isolates and the innate immune response to Shigella, (iii) a pioneering oral mouse model of shigellosis, which has helped to discover new inflammasome biology and protective mechanisms against shigellosis, and (iv) the controlled human infection model, which has been effective in translating basic research into human health impact and assessing suitability of novel vaccine candidates. We consider the recent contributions of each model and discuss where the future of modelling Shigella infection lies.
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Affiliation(s)
- Sydney L Miles
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Kathryn E Holt
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Victoria 3004, Australia
| | - Serge Mostowy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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5
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Li C, Wei Z, He X, He H, Liu Y, Zuo Y, Xiao H, Wang Y, Shen X, Zhu L. OxyR-regulated T6SS functions in coordination with siderophore to resist oxidative stress. Microbiol Spectr 2024; 12:e0323123. [PMID: 38189330 PMCID: PMC10846153 DOI: 10.1128/spectrum.03231-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 12/02/2023] [Indexed: 01/09/2024] Open
Abstract
The formation of reactive oxygen species is harmful and can destroy intracellular macromolecules such as lipids, proteins, and DNA, even leading to bacterial death. To cope with this situation, microbes have evolved a variety of sophisticated mechanisms, including antioxidant enzymes, siderophores, and the type VI secretion system (T6SS). However, the mechanism of oxidative stress resistance in Cupriavidus pinatubonensis is unclear. In this study, we identified Reut_A2805 as an OxyR ortholog in C. pinatubonensis, which positively regulated the expression of T6SS1 by directly binding to its operon promoter region. The study revealed that OxyR-regulated T6SS1 combats oxidative stress by importing iron into bacterial cells. Moreover, the T6SS1-mediated outer membrane vesicles-dependent iron acquisition pathway played a crucial role in the oxidative stress resistance process. Finally, our study demonstrated that the T6SS1 and siderophore systems in C. pinatubonensis exhibit different responses in combating oxidative stress under low-iron conditions, providing a comprehensive understanding of how bacterial iron acquisition systems function in diverse conditions.IMPORTANCEThe ability to eliminate reactive oxygen species is crucial for bacterial survival. Continuous formation of hydroperoxides can damage metalloenzymes, disrupt DNA integrity, and even result in cell death. While various mechanisms have been identified in other bacterial species to combat oxidative stress, the specific mechanism of oxidative stress resistance in C. pinatubonensis remains unclear. The importance of this study is that we elucidate the mechanism that OxyR-regulated T6SS1 combats oxidative stress by importing iron with the help of bacterial outer membrane vesicle. Moreover, the study highlights the contrasting responses of T6SS1- and siderophore-mediated iron acquisition systems to oxidative stress. This study provides a comprehensive understanding of bacterial iron acquisition and its role in oxidative stress resistance in C. pinatubonensis under low-iron conditions.
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Affiliation(s)
- Changfu Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhiyan Wei
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Xinquan He
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Haiyang He
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Yuqi Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Yuxin Zuo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - He Xiao
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Yao Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
| | - Lingfang Zhu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
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Leung PB, Matanza XM, Roche B, Ha KP, Cheung HC, Appleyard S, Collins T, Flanagan O, Marteyn BS, Clements A. Shigella sonnei utilises colicins during inter-bacterial competition. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001434. [PMID: 38376387 PMCID: PMC10924462 DOI: 10.1099/mic.0.001434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 01/25/2024] [Indexed: 02/21/2024]
Abstract
The mammalian colon is one of the most densely populated habitats currently recognised, with 1011-1013 commensal bacteria per gram of colonic contents. Enteric pathogens must compete with the resident intestinal microbiota to cause infection. Among these enteric pathogens are Shigella species which cause approximately 125 million infections annually, of which over 90 % are caused by Shigella flexneri and Shigella sonnei. Shigella sonnei was previously reported to use a Type VI Secretion System (T6SS) to outcompete E. coli and S. flexneri in in vitro and in vivo experiments. S. sonnei strains have also been reported to harbour colicinogenic plasmids, which are an alternative anti-bacterial mechanism that could provide a competitive advantage against the intestinal microbiota. We sought to determine the contribution of both T6SS and colicins to the anti-bacterial killing activity of S. sonnei. We reveal that whilst the T6SS operon is present in S. sonnei, there is evidence of functional degradation of the system through SNPs, indels and IS within key components of the system. We created strains with synthetically inducible T6SS operons but were still unable to demonstrate anti-bacterial activity of the T6SS. We demonstrate that the anti-bacterial activity observed in our in vitro assays was due to colicin activity. We show that S. sonnei no longer displayed anti-bacterial activity against bacteria that were resistant to colicins, and removal of the colicin plasmid from S. sonnei abrogated anti-bacterial activity of S. sonnei. We propose that the anti-bacterial activity demonstrated by colicins may be sufficient for niche competition by S. sonnei within the gastrointestinal environment.
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Affiliation(s)
- P. B. Leung
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - X. M. Matanza
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - B. Roche
- Universite de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, CNRS UPR9002, F-67000 Strasbourg, France
| | - K. P. Ha
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - H. C. Cheung
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - S. Appleyard
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - T. Collins
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - O. Flanagan
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
| | - B. S. Marteyn
- Universite de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, CNRS UPR9002, F-67000 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), F-67000 Strasbourg, France
- Institut Pasteur, Université de Paris, Inserm U1225, Unité de Pathogenèse des Infections Vasculaires, F-75015 Paris, France
| | - A. Clements
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, SW72AZ, UK
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Jiang X, Li H, Ma J, Li H, Ma X, Tang Y, Li J, Chi X, Deng Y, Zeng S, Liu Z. Role of Type VI secretion system in pathogenic remodeling of host gut microbiota during Aeromonas veronii infection. THE ISME JOURNAL 2024; 18:wrae053. [PMID: 38531781 PMCID: PMC11014884 DOI: 10.1093/ismejo/wrae053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/31/2024] [Accepted: 03/21/2024] [Indexed: 03/28/2024]
Abstract
Intestinal microbial disturbance is a direct cause of host disease. The bacterial Type VI secretion system (T6SS) often plays a crucial role in the fitness of pathogenic bacteria by delivering toxic effectors into target cells. However, its impact on the gut microbiota and host pathogenesis is poorly understood. To address this question, we characterized a new T6SS in the pathogenic Aeromonas veronii C4. First, we validated the secretion function of the core machinery of A. veronii C4 T6SS. Second, we found that the pathogenesis and colonization of A. veronii C4 is largely dependent on its T6SS. The effector secretion activity of A. veronii C4 T6SS not only provides an advantage in competition among bacteria in vitro, but also contributes to occupation of an ecological niche in the nutritionally deficient and anaerobic environment of the host intestine. Metagenomic analysis showed that the T6SS directly inhibits or eliminates symbiotic strains from the intestine, resulting in dysregulated gut microbiome homeostasis. In addition, we identified three unknown effectors, Tse1, Tse2, and Tse3, in the T6SS, which contribute to T6SS-mediated bacterial competition and pathogenesis by impairing targeted cell integrity. Our findings highlight that T6SS can remodel the host gut microbiota by intricate interplay between T6SS-mediated bacterial competition and altered host immune responses, which synergistically promote pathogenesis of A. veronii C4. Therefore, this newly characterized T6SS could represent a general interaction mechanism between the host and pathogen, and may offer a potential therapeutic target for controlling bacterial pathogens.
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Affiliation(s)
- Xiaoli Jiang
- School of Life and Health Sciences, Hainan University, Haikou 570228, China
| | - Hanzeng Li
- School of Life and Health Sciences, Hainan University, Haikou 570228, China
| | - Jiayue Ma
- School of Life and Health Sciences, Hainan University, Haikou 570228, China
| | - Hong Li
- School of Life and Health Sciences, Hainan University, Haikou 570228, China
| | - Xiang Ma
- School of Life and Health Sciences, Hainan University, Haikou 570228, China
| | - Yanqiong Tang
- School of Life and Health Sciences, Hainan University, Haikou 570228, China
| | - Juanjuan Li
- School of Life and Health Sciences, Hainan University, Haikou 570228, China
| | - Xue Chi
- School of Life and Health Sciences, Hainan University, Haikou 570228, China
| | - Yong Deng
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Sheng Zeng
- Susheng Biotech (Hainan) Co., Ltd, Haikou 570228, China
| | - Zhu Liu
- School of Life and Health Sciences, Hainan University, Haikou 570228, China
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8
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Wang M, Zeng J, Tan H, Guo Q, Li X, Ling X, Zhang J, Song S, Deng Y. Anti-virulence and bactericidal activities of Stattic against Shigella sonnei. Appl Environ Microbiol 2023; 89:e0107423. [PMID: 38032177 PMCID: PMC10734500 DOI: 10.1128/aem.01074-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 10/13/2023] [Indexed: 12/01/2023] Open
Abstract
IMPORTANCE Shigella sonnei is a major human enteric pathogen that causes bacillary dysentery. The increasing spread of drug-resistant S. sonnei strains has caused an emergent need for the development of new antimicrobial agents against this pathogenic bacterium. In this study, we demonstrate that Stattic employs two antibacterial mechanisms against S. sonnei. It exerted both anti-virulence activity and bactericidal activity against S. sonnei, suggesting that it shows advantages over traditional antibiotics. Moreover, Stattic showed excellent synergistic effects with kanamycin, ampicillin, chloramphenicol, and gentamicin against S. sonnei. Our findings suggest that Stattic has promising potential for development as a new antibiotic or as an adjuvant to antibiotics for infections caused by S. sonnei.
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Affiliation(s)
- Mingfang Wang
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Jia Zeng
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Huihui Tan
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Quan Guo
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Xia Li
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Xiwen Ling
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Jinyue Zhang
- School of Pharmaceutical Sciences, Hainan University, Haikou, China
| | - Shihao Song
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
- School of Pharmaceutical Sciences, Hainan University, Haikou, China
| | - Yinyue Deng
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
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9
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Taillefer B, Giraud JF, Cascales E. No fitness cost entailed by type VI secretion system synthesis, assembly, contraction, or disassembly in enteroaggregative Escherichia coli. J Bacteriol 2023; 205:e0035723. [PMID: 37971272 PMCID: PMC10729742 DOI: 10.1128/jb.00357-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 11/19/2023] Open
Abstract
IMPORTANCE Bacteria use weapons to deliver effectors into target cells. One of these weapons, the type VI secretion system (T6SS), assembles a contractile tail acting as a spring to propel a toxin-loaded needle. Due to its size and mechanism of action, the T6SS was intuitively thought to be energetically costly. Here, using a combination of mutants and growth measurements in liquid medium, on plates, and in competition experiments, we show that the T6SS does not entail a growth cost to enteroaggregative Escherichia coli.
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Affiliation(s)
- Boris Taillefer
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR 7255), Institut de Microbiologie de la Méditerranée (IMM), Aix Marseille Univ, CNRS, Marseille, France
| | - Julien F. Giraud
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR 7255), Institut de Microbiologie de la Méditerranée (IMM), Aix Marseille Univ, CNRS, Marseille, France
| | - Eric Cascales
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR 7255), Institut de Microbiologie de la Méditerranée (IMM), Aix Marseille Univ, CNRS, Marseille, France
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10
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Matanza XM, Clements A. Pathogenicity and virulence of Shigella sonnei: A highly drug-resistant pathogen of increasing prevalence. Virulence 2023; 14:2280838. [PMID: 37994877 PMCID: PMC10732612 DOI: 10.1080/21505594.2023.2280838] [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] [Accepted: 11/01/2023] [Indexed: 11/24/2023] Open
Abstract
Shigella spp. are the causative agent of shigellosis (or bacillary dysentery), a diarrhoeal disease characterized for the bacterial invasion of gut epithelial cells. Among the 4 species included in the genus, Shigella flexneri is principally responsible for the disease in the developing world while Shigella sonnei is the main causative agent in high-income countries. Remarkably, as more countries improve their socioeconomic conditions, we observe an increase in the relative prevalence of S. sonnei. To date, the reasons behind this change in aetiology depending on economic growth are not understood. S. flexneri has been widely used as a model to study the pathogenesis of the genus, but as more research data are collected, important discrepancies with S. sonnei have come to light. In comparison to S. flexneri, S. sonnei can be differentiated in numerous aspects; it presents a characteristic O-antigen identical to that of one serogroup of the environmental bacterium Plesiomonas shigelloides, a group 4 capsule, antibacterial mechanisms to outcompete and displace gut commensal bacteria, and a poorer adaptation to an intracellular lifestyle. In addition, the World Health Organization (WHO) have recognized the significant threat posed by antibiotic-resistant strains of S. sonnei, demanding new approaches. This review gathers knowledge on what is known about S. sonnei within the context of other Shigella spp. and aims to open the door for future research on understanding the increasing spread of this pathogen.
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Affiliation(s)
- Xosé M. Matanza
- Centre for Bacterial Resistance Biology, Department of Life Sciences, Imperial College London, London, UK
| | - Abigail Clements
- Centre for Bacterial Resistance Biology, Department of Life Sciences, Imperial College London, London, UK
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11
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Skerniskyte J, Mulet C, André AC, Anderson MC, Injarabian L, Buck A, Prade VM, Sansonetti PJ, Reibel-Foisset S, Walch AK, Lebel M, Lykkesfeldt J, Marteyn BS. Ascorbate deficiency increases progression of shigellosis in guinea pigs and mice infection models. Gut Microbes 2023; 15:2271597. [PMID: 37876025 PMCID: PMC10730169 DOI: 10.1080/19490976.2023.2271597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 10/12/2023] [Indexed: 10/26/2023] Open
Abstract
Shigella spp. are the causative agents of bacterial dysentery and shigellosis, mainly in children living in developing countries. The study of Shigella entire life cycle in vivo and the evaluation of vaccine candidates' protective efficacy have been hampered by the lack of a suitable animal model of infection. None of the studies evaluated so far (rabbit, guinea pig, mouse) allowed the recapitulation of full shigellosis symptoms upon Shigella oral challenge. Historical reports have suggested that dysentery and scurvy are both metabolic diseases associated with ascorbate deficiency. Mammals, which are susceptible to Shigella infection (humans, non-human primates and guinea pigs) are among the few species unable to synthesize ascorbate. We optimized a low-ascorbate diet to induce moderate ascorbate deficiency, but not scurvy, in guinea pigs to investigate whether poor vitamin C status increases the progression of shigellosis. Moderate ascorbate deficiency increased shigellosis symptom severity during an extended period of time (up to 48 h) in all strains tested (Shigella sonnei, Shigella flexneri 5a, and 2a). At late time points, an important influx of neutrophils was observed both within the disrupted colonic mucosa and in the luminal compartment, although Shigella was able to disseminate deep into the organ to reach the sub-mucosal layer and the bloodstream. Moreover, we found that ascorbate deficiency also increased Shigella penetration into the colon epithelium layer in a Gulo-/- mouse infection model. The use of these new rodent models of shigellosis opens new doors for the study of both Shigella infection strategies and immune responses to Shigella infection.
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Affiliation(s)
- Jurate Skerniskyte
- Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l’ARN, Université de Strasbourg, Strasbourg, France
| | - Céline Mulet
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Université de Paris, Paris, France
| | - Antonin C. André
- Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l’ARN, Université de Strasbourg, Strasbourg, France
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Université de Paris, Paris, France
| | - Mark C. Anderson
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Université de Paris, Paris, France
| | - Louise Injarabian
- Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l’ARN, Université de Strasbourg, Strasbourg, France
| | - Achim Buck
- Research Unit Analytical Pathology, Helmholtz Zentrum München – German Research Center for Environmental Health, Neuherberg, Germany
| | - Verena M. Prade
- Research Unit Analytical Pathology, Helmholtz Zentrum München – German Research Center for Environmental Health, Neuherberg, Germany
| | - Philippe J. Sansonetti
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Université de Paris, Paris, France
- Collège de France, Paris, France
| | | | - Axel K. Walch
- Research Unit Analytical Pathology, Helmholtz Zentrum München – German Research Center for Environmental Health, Neuherberg, Germany
| | - Michel Lebel
- Centre de recherche du CHU de Québec, Faculty of Medicine, Université Laval, Québec, Canada
| | - Jens Lykkesfeldt
- Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University Copenhagen, Copenhagen, Denmark
| | - Benoit S. Marteyn
- Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l’ARN, Université de Strasbourg, Strasbourg, France
- Unité de Pathogenèse des Infections Vasculaires, Institut Pasteur, INSERM U1225, Paris, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
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12
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Alphonse N, Odendall C. Animal models of shigellosis: a historical overview. Curr Opin Immunol 2023; 85:102399. [PMID: 37952487 DOI: 10.1016/j.coi.2023.102399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 11/14/2023]
Abstract
Shigella spp. are major causative agents of bacillary dysentery, a severe enteric disease characterized by destruction and inflammation of the colonic epithelium accompanied by acute diarrhea, fever, and abdominal pain. Although antibiotics have traditionally been effective, the prevalence of multidrug-resistant strains is increasing, stressing the urgent need for a vaccine. The human-specific nature of shigellosis and the absence of a dependable animal model have posed significant obstacles in understanding Shigella pathogenesis and the host immune response, both of which are crucial for the development of an effective vaccine. Efforts have been made over time to develop a physiological model that mimics the pathological features of the human disease with limited success until the recent development of genetically modified mouse models. In this review, we provide an overview of Shigella pathogenesis and chronicle the historical development of various shigellosis models, emphasizing their strengths and weaknesses.
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Affiliation(s)
- Noémie Alphonse
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK; Immunoregulation Laboratory, Francis Crick Institute, London, UK.
| | - Charlotte Odendall
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK.
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13
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Robitaille S, Simmons EL, Verster AJ, McClure EA, Royce DB, Trus E, Swartz K, Schultz D, Nadell CD, Ross BD. Community composition and the environment modulate the population dynamics of type VI secretion in human gut bacteria. Nat Ecol Evol 2023; 7:2092-2107. [PMID: 37884689 PMCID: PMC11099977 DOI: 10.1038/s41559-023-02230-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 09/21/2023] [Indexed: 10/28/2023]
Abstract
Understanding the relationship between the composition of the human gut microbiota and the ecological forces shaping it is of great importance; however, knowledge of the biogeographical and ecological relationships between physically interacting taxa is limited. Interbacterial antagonism may play an important role in gut community dynamics, yet the conditions under which antagonistic behaviour is favoured or disfavoured by selection in the gut are not well understood. Here, using genomics, we show that a species-specific type VI secretion system (T6SS) repeatedly acquires inactivating mutations in Bacteroides fragilis in the human gut. This result implies a fitness cost to the T6SS, but we could not identify laboratory conditions under which such a cost manifests. Strikingly, experiments in mice illustrate that the T6SS can be favoured or disfavoured in the gut depending on the strains and species in the surrounding community and their susceptibility to T6SS antagonism. We use ecological modelling to explore the conditions that could underlie these results and find that community spatial structure modulates interaction patterns among bacteria, thereby modulating the costs and benefits of T6SS activity. Our findings point towards new integrative models for interrogating the evolutionary dynamics of type VI secretion and other modes of antagonistic interaction in microbiomes.
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Affiliation(s)
- Sophie Robitaille
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Emilia L Simmons
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - Adrian J Verster
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Emily Ann McClure
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Darlene B Royce
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Evan Trus
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Kerry Swartz
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Daniel Schultz
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Carey D Nadell
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - Benjamin D Ross
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.
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14
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De Silva PM, Bennett RJ, Kuhn L, Ngondo P, Debande L, Njamkepo E, Ho B, Weill FX, Marteyn BS, Jenkins C, Baker KS. Escherichia coli killing by epidemiologically successful sublineages of Shigella sonnei is mediated by colicins. EBioMedicine 2023; 97:104822. [PMID: 37806286 PMCID: PMC10579285 DOI: 10.1016/j.ebiom.2023.104822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 09/20/2023] [Accepted: 09/21/2023] [Indexed: 10/10/2023] Open
Abstract
BACKGROUND Shigella sp. are enteric pathogens which causes >125 million cases of shigellosis annually. S. sonnei accounts for about a quarter of those cases and is increasingly prevalent in industrialising nations. Being an enteric pathogen, S. sonnei benefits from outcompeting gut commensals such as Escherichia coli to establish itself and cause disease. There are numerous mechanisms that bacterial pathogens use to outcompete its rivals including molecules called colicins. A Type 6 Secretion System (T6SS) was recently described as contributing to E. coli killing in S. sonnei. METHODS We used Bulk Phenotyping of Epidemiological Replicates (BPER) which combined bacterial Genome Wide Association Studies (bGWAS) and high throughput phenotyping on a collection of S. sonnei surveillance isolates to identify the genetic features associated with E. coli killing and explore their relationship with epidemiological behaviour. We further explored the presence of colicins and T6SS components in the isolates using genomics, laboratory experimentation, and proteomics. FINDINGS Our bGWAS analysis returned known and novel colicin and colicin related genes as significantly associated with E. coli killing. In silico analyses identified key colicin clusters responsible for the killing phenotype associated with epidemiologically successful sub-lineages. The killing phenotype was not associated with the presence of a T6SS. Laboratory analyses confirmed the presence of the key colicin clusters and that killing was contact-independent. INTERPRETATION Colicins are responsible for E. coli killing by S. sonnei, not a T6SS. This phenotype contributes to shaping the observed epidemiology of S. sonnei and may contribute to its increasing prevalence globally. BPER is an epidemiologically relevant approach to phenotypic testing that enables the rapid identification of genetic drivers of phenotypic changes, and assessment of their relevance to epidemiology in natural settings. FUNDING Biotechnology and Biological Sciences Research Council, Biotechnology and Biological Sciences Research Council Doctoral Training Partnership studentship, Wellcome Trust, Medical Research Council (UK), French National Research Agency.
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Affiliation(s)
- P Malaka De Silva
- Department of Clinical Infection, Microbiology, and Immunology, Institute for Infection, Veterinary, and Ecological Sciences (IVES), University of Liverpool, Liverpool, United Kingdom
| | - Rebecca J Bennett
- Department of Clinical Infection, Microbiology, and Immunology, Institute for Infection, Veterinary, and Ecological Sciences (IVES), University of Liverpool, Liverpool, United Kingdom
| | - Lauriane Kuhn
- Plateforme protéomique Strasbourg Esplanade FR1589 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Patryk Ngondo
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, F-67000, Strasbourg, France
| | - Lorine Debande
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, F-67000, Strasbourg, France
| | - Elisabeth Njamkepo
- Institut Pasteur, Université Paris Cité, Unité des Bactéries pathogènes entériques, Centre National de Référence des Escherichia coli, Shigella et Salmonella, Paris, F-75015, France
| | - Brian Ho
- Institute of Structural and Molecular Biology, University College London and Birkbeck, London, UK
| | - François-Xavier Weill
- Institut Pasteur, Université Paris Cité, Unité des Bactéries pathogènes entériques, Centre National de Référence des Escherichia coli, Shigella et Salmonella, Paris, F-75015, France
| | - Benoît S Marteyn
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, F-67000, Strasbourg, France
| | - Claire Jenkins
- Gastro and Food Safety (One Health) Division, UK Health Security Agency, Colindale, London, UK
| | - Kate S Baker
- Department of Clinical Infection, Microbiology, and Immunology, Institute for Infection, Veterinary, and Ecological Sciences (IVES), University of Liverpool, Liverpool, United Kingdom; Department of Genetics, University of Cambridge, Downing Place, Cambridge, UK.
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15
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Santos-Júnior CD, Der Torossian Torres M, Duan Y, del Río ÁR, Schmidt TS, Chong H, Fullam A, Kuhn M, Zhu C, Houseman A, Somborski J, Vines A, Zhao XM, Bork P, Huerta-Cepas J, de la Fuente-Nunez C, Coelho LP. Computational exploration of the global microbiome for antibiotic discovery. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.31.555663. [PMID: 37693522 PMCID: PMC10491242 DOI: 10.1101/2023.08.31.555663] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Novel antibiotics are urgently needed to combat the antibiotic-resistance crisis. We present a machine learning-based approach to predict prokaryotic antimicrobial peptides (AMPs) by leveraging a vast dataset of 63,410 metagenomes and 87,920 microbial genomes. This led to the creation of AMPSphere, a comprehensive catalog comprising 863,498 non-redundant peptides, the majority of which were previously unknown. We observed that AMP production varies by habitat, with animal-associated samples displaying the highest proportion of AMPs compared to other habitats. Furthermore, within different human-associated microbiota, strain-level differences were evident. To validate our predictions, we synthesized and experimentally tested 50 AMPs, demonstrating their efficacy against clinically relevant drug-resistant pathogens both in vitro and in vivo. These AMPs exhibited antibacterial activity by targeting the bacterial membrane. Additionally, AMPSphere provides valuable insights into the evolutionary origins of peptides. In conclusion, our approach identified AMP sequences within prokaryotic microbiomes, opening up new avenues for the discovery of antibiotics.
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Affiliation(s)
- Célio Dias Santos-Júnior
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai, China
| | - Marcelo Der Torossian Torres
- Machine Biology Group, Departments of Psychiatry and Microbiology, Institute for Biomedical Informatics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania; Philadelphia, Pennsylvania, United States of America
- Departments of Bioengineering and Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania; Philadelphia, Pennsylvania, United States of America
- Penn Institute for Computational Science, University of Pennsylvania; Philadelphia, Pennsylvania, United States of America
| | - Yiqian Duan
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai, China
| | - Álvaro Rodríguez del Río
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Campus de Montegancedo-UPM, 28223 Pozuelo de Alarcón, Madrid, Spain
| | - Thomas S.B. Schmidt
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Hui Chong
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai, China
| | - Anthony Fullam
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Michael Kuhn
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Chengkai Zhu
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai, China
| | - Amy Houseman
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai, China
| | - Jelena Somborski
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai, China
| | - Anna Vines
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai, China
| | - Xing-Ming Zhao
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai, China
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, China
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, China
- MOE Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence
- MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
- International Human Phenome Institute, Shanghai, China
| | - Peer Bork
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Max Delbrück Centre for Molecular Medicine, Berlin, Germany
- Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jaime Huerta-Cepas
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Campus de Montegancedo-UPM, 28223 Pozuelo de Alarcón, Madrid, Spain
| | - Cesar de la Fuente-Nunez
- Machine Biology Group, Departments of Psychiatry and Microbiology, Institute for Biomedical Informatics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania; Philadelphia, Pennsylvania, United States of America
- Departments of Bioengineering and Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania; Philadelphia, Pennsylvania, United States of America
- Penn Institute for Computational Science, University of Pennsylvania; Philadelphia, Pennsylvania, United States of America
| | - Luis Pedro Coelho
- Institute of Science and Technology for Brain-Inspired Intelligence - ISTBI, Fudan University, Shanghai, China
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16
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Hespanhol JT, Nóbrega-Silva L, Bayer-Santos E. Regulation of type VI secretion systems at the transcriptional, posttranscriptional and posttranslational level. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001376. [PMID: 37552221 PMCID: PMC10482370 DOI: 10.1099/mic.0.001376] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/25/2023] [Indexed: 08/09/2023]
Abstract
Bacteria live in complex polymicrobial communities and are constantly competing for resources. The type VI secretion system (T6SS) is a widespread antagonistic mechanism used by Gram-negative bacteria to gain an advantage over competitors. T6SSs translocate toxic effector proteins inside target prokaryotic cells in a contact-dependent manner. In addition, some T6SS effectors can be secreted extracellularly and contribute to the scavenging scarce metal ions. Bacteria deploy their T6SSs in different situations, categorizing these systems into offensive, defensive and exploitative. The great variety of bacterial species and environments occupied by such species reflect the complexity of regulatory signals and networks that control the expression and activation of the T6SSs. Such regulation is tightly controlled at the transcriptional, posttranscriptional and posttranslational level by abiotic (e.g. pH, iron) or biotic (e.g. quorum-sensing) cues. In this review, we provide an update on the current knowledge about the regulatory networks that modulate the expression and activity of T6SSs across several species, focusing on systems used for interbacterial competition.
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Affiliation(s)
- Julia Takuno Hespanhol
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-900, Brazil
| | - Luize Nóbrega-Silva
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-900, Brazil
| | - Ethel Bayer-Santos
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-900, Brazil
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17
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Wang M, Zeng J, Zhu Y, Chen X, Guo Q, Tan H, Cui B, Song S, Deng Y. A 4-Hydroxybenzoic Acid-Mediated Signaling System Controls the Physiology and Virulence of Shigella sonnei. Microbiol Spectr 2023; 11:e0483522. [PMID: 37036340 PMCID: PMC10269604 DOI: 10.1128/spectrum.04835-22] [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: 11/24/2022] [Accepted: 03/15/2023] [Indexed: 04/11/2023] Open
Abstract
Many bacteria use small molecules, such as quorum sensing (QS) signals, to perform intraspecies signaling and interspecies or interkingdom communication. Previous studies demonstrated that some bacteria regulate their physiology and pathogenicity by employing 4-hydroxybenzoic acid (4-HBA). Here, we report that 4-HBA controls biological functions, virulence, and anthranilic acid production in Shigella sonnei. The biosynthesis of 4-HBA is performed by UbiC (SSON_4219), which is a chorismate pyruvate-lyase that catalyzes the conversion of chorismate to 4-HBA. Deletion of ubiC caused S. sonnei to exhibit impaired phenotypes, including impaired biofilm formation, extracellular polysaccharide (EPS) production, and virulence. In addition, we found that 4-HBA controls the physiology and virulence of S. sonnei through the response regulator AaeR (SSON_3385), which contains a helix-turn-helix (HTH) domain and a LysR substrate-binding (LysR_substrate) domain. The same biological functions are controlled by AaeR and the 4-HBA signal, and 4-HBA-deficient mutant phenotypes were rescued by in trans expression of AaeR. We found that 4-HBA binds to AaeR and then enhances the binding of AaeR to the promoter DNA regions in target genes. Moreover, we revealed that 4-HBA from S. sonnei reduces the competitive fitness of Candida albicans by interfering with morphological transition. Together, our results suggested that the 4-HBA signaling system plays crucial roles in bacterial physiology and interkingdom communication. IMPORTANCE Shigella sonnei is an important pathogen in human intestines. Following previous findings that some bacteria employ 4-HBA as a QS signal to regulate biological functions, we demonstrate that 4-HBA controls the physiology and virulence of S. sonnei. This study is significant because it identifies both the signal synthase UbiC and receptor AaeR and unveils the signaling pathway of 4-HBA in S. sonnei. In addition, this study also supports the important role of 4-HBA in microbial cross talk, as 4-HBA strongly inhibits hyphal formation by Candida albicans. Together, our findings describe the dual roles of 4-HBA in both intraspecies signaling and interkingdom communication.
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Affiliation(s)
- Mingfang Wang
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen, China
| | - Jia Zeng
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen, China
| | - Yu Zhu
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen, China
| | - Xiayu Chen
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen, China
| | - Quan Guo
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen, China
| | - Huihui Tan
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen, China
| | - Binbin Cui
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen, China
| | - Shihao Song
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen, China
- School of Pharmaceutical Sciences, Hainan University, Haikou, China
| | - Yinyue Deng
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen, China
- School of Pharmaceutical Sciences, Hainan University, Haikou, China
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18
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Caballero-Flores G, Pickard JM, Núñez G. Microbiota-mediated colonization resistance: mechanisms and regulation. Nat Rev Microbiol 2023; 21:347-360. [PMID: 36539611 PMCID: PMC10249723 DOI: 10.1038/s41579-022-00833-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2022] [Indexed: 12/24/2022]
Abstract
A dense and diverse microbial community inhabits the gut and many epithelial surfaces. Referred to as the microbiota, it co-evolved with the host and is beneficial for many host physiological processes. A major function of these symbiotic microorganisms is protection against pathogen colonization and overgrowth of indigenous pathobionts. Dysbiosis of the normal microbial community increases the risk of pathogen infection and overgrowth of harmful pathobionts. The protective mechanisms conferred by the microbiota are complex and include competitive microbial-microbial interactions and induction of host immune responses. Pathogens, in turn, have evolved multiple strategies to subvert colonization resistance conferred by the microbiota. Understanding the mechanisms by which microbial symbionts limit pathogen colonization should guide the development of new therapeutic approaches to prevent or treat disease.
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Affiliation(s)
- Gustavo Caballero-Flores
- Department of Pathology and Rogel Cancer Center, The University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Joseph M Pickard
- Department of Pathology and Rogel Cancer Center, The University of Michigan Medical School, Ann Arbor, MI, USA
| | - Gabriel Núñez
- Department of Pathology and Rogel Cancer Center, The University of Michigan Medical School, Ann Arbor, MI, USA.
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19
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Rudzite M, Subramoni S, Endres RG, Filloux A. Effectiveness of Pseudomonas aeruginosa type VI secretion system relies on toxin potency and type IV pili-dependent interaction. PLoS Pathog 2023; 19:e1011428. [PMID: 37253075 PMCID: PMC10281587 DOI: 10.1371/journal.ppat.1011428] [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: 11/30/2022] [Revised: 06/20/2023] [Accepted: 05/17/2023] [Indexed: 06/01/2023] Open
Abstract
The type VI secretion system (T6SS) is an antibacterial weapon that is used by numerous Gram-negative bacteria to gain competitive advantage by injecting toxins into adjacent prey cells. Predicting the outcome of a T6SS-dependent competition is not only reliant on presence-absence of the system but instead involves a multiplicity of factors. Pseudomonas aeruginosa possesses 3 distinct T6SSs and a set of more than 20 toxic effectors with diverse functions including disruption of cell wall integrity, degradation of nucleic acids or metabolic impairment. We generated a comprehensive collection of mutants with various degrees of T6SS activity and/or sensitivity to each individual T6SS toxin. By imaging whole mixed bacterial macrocolonies, we then investigated how these P. aeruginosa strains gain a competitive edge in multiple attacker/prey combinations. We observed that the potency of single T6SS toxin varies significantly from one another as measured by monitoring the community structure, with some toxins acting better in synergy or requiring a higher payload. Remarkably the degree of intermixing between preys and attackers is also key to the competition outcome and is driven by the frequency of contact as well as the ability of the prey to move away from the attacker using type IV pili-dependent twitching motility. Finally, we implemented a computational model to better understand how changes in T6SS firing behaviours or cell-cell contacts lead to population level competitive advantages, thus providing conceptual insight applicable to all types of contact-based competition.
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Affiliation(s)
- Marta Rudzite
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Sujatha Subramoni
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Robert G. Endres
- Centre for Integrative Systems Biology and Bioinformatics, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Alain Filloux
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
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20
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Bai X, Chen T, Liu X, Liu Z, Ma R, Su R, Li X, Lü X, Xia X, Shi C. Antibacterial Activity and Possible Mechanism of Litsea cubeba Essential Oil Against Shigella sonnei and Its Application in Lettuce. Foodborne Pathog Dis 2023; 20:138-148. [PMID: 37010405 DOI: 10.1089/fpd.2022.0084] [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] [Indexed: 04/04/2023] Open
Abstract
Shigella sonnei, the causative agents of bacillary dysentery, remains a significant threat to public health. Litsea cubeba essential oil (LC-EO), one of the natural essential oils, exhibited promising biological activities. In this study, the antibacterial effects and possible mechanisms of LC-EO on S. sonnei and its application in lettuce medium were investigated. The minimum inhibitory concentration (MIC) of LC-EO against S. sonnei ATCC 25931 and CMCC 51592 was 4 and 6 μL/mL, respectively. The LC-EO could inhibit the growth of S. sonnei, and decreased S. sonnei to undetectable levels with 4 μL/mL for 1 h in Luria-Bertani broth. The antibacterial mechanism indicated that after the treatment of LC-EO, the production of reactive oxygen species and the activity of superoxide dismutase were significantly elevated in S. sonnei cells, and eventually led to the lipid oxidation product, the malondialdehyde content that significantly increased. Moreover, LC-EO at 2 MIC could destroy 96.51% of bacterial cell membrane integrity, and made S. sonnei cells to appear wrinkled with a rough surface, so that the intracellular adenosine triphosphate leakage was about 0.352-0.030 μmol/L. Finally, the results of application evaluation indicated that the addition of LC-EO at 4 μL/mL in lettuce leaves and 6 μL/mL in lettuce juice could decrease the number of S. sonnei to undetectable levels without remarkable influence on the lettuce leaf sensory quality. In summary, LC-EO exerted strong antibacterial activity and has the potential to control S. sonnei in food industry.
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Affiliation(s)
- Xiangyang Bai
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Tianxiao Chen
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Xiaoxiao Liu
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Zhijie Liu
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Run Ma
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Ruiying Su
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Xuejiao Li
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Xin Lü
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Xiaodong Xia
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, China
| | - Chao Shi
- College of Food Science and Engineering, Northwest A&F University, Yangling, China
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21
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Modelling the Gastrointestinal Carriage of Klebsiella pneumoniae Infections. mBio 2023; 14:e0312122. [PMID: 36598189 PMCID: PMC9972987 DOI: 10.1128/mbio.03121-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Klebsiella pneumoniae is a leading cause of nosocomial and community acquired infections, making K. pneumoniae the pathogen that is associated with the second largest number of deaths attributed to any antibiotic resistant infection. K. pneumoniae colonizes the nasopharynx and the gastrointestinal tract in an asymptomatic manner without dissemination to other tissues. Importantly, gastrointestinal colonization is a requisite for infection. Our understanding of K. pneumoniae colonization is still based on interrogating mouse models in which animals are pretreated with antibiotics to disturb the colonization resistance imposed by the gut microbiome. In these models, infections disseminate to other tissues. Here, we report a murine model to allow for the study of the gastrointestinal colonization of K. pneumoniae without tissue dissemination. Hypervirulent and antibiotic resistant strains stably colonize the gastrointestinal tract of in an inbred mouse population without antibiotic treatment. The small intestine is the primary site of colonization and is followed by a transition to the colon over time, without dissemination to other tissues. Our model recapitulates the disease dynamics of the metastatic K. pneumoniae strains that are able to disseminate from the gastrointestinal tract to other sterile sites. Colonization is associated with mild to moderate histopathology, no significant inflammation, and no effect on the richness of the microbiome. Our model sums up the clinical scenario in which antibiotic treatment disturbs the colonization of K. pneumoniae and results in dissemination to other tissues. Finally, we establish that the capsule polysaccharide is necessary for the colonization of the large intestine, whereas the type VI secretion system contributes to colonization across the gastrointestinal tract. IMPORTANCE Klebsiella pneumoniae is one of the pathogens that is sweeping the world in the antibiotic resistance pandemic. Klebsiella colonizes the nasopharynx and the gut of healthy subjects in an asymptomatic manner, making gut colonization a requisite for infection. This makes it essential to understand the gastrointestinal carriage in preventing Klebsiella infections. Current research models rely on the perturbation of the gut microbiome by antibiotics, resulting in an invasive infection. Here, we report a new model of K. pneumoniae gut colonization that recapitulates key features of the asymptomatic human gastrointestinal tract colonization. In our model, there is no need to disturb the microbiota to achieve stable colonization, and there is no dissemination to other tissues. Our model sums up the clinical scenario in which antibiotic treatment triggers invasive infection. We envision that our model will be an excellent platform upon which to investigate factors enhancing colonization and invasive infections and to test therapeutics to eliminate Klebsiella asymptomatic colonization.
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22
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Wang H, Lv LB, Chen LP, Xiao JL, Shen J, Gao B, Zhao JG, Han DM, Chen BX, Wang S, Liu G, Xin AG, Xiao P, Gao H. Hemolysin Co-Regulatory Protein 1 Enhances the Virulence of Clinically Isolated Escherichia coli in KM Mice by Increasing Inflammation and Inducing Pyroptosis. Toxins (Basel) 2023; 15:171. [PMID: 36977062 PMCID: PMC10058142 DOI: 10.3390/toxins15030171] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/13/2023] [Accepted: 02/15/2023] [Indexed: 02/25/2023] Open
Abstract
Hemolysin-coregulated protein 1 (Hcp1) is an effector released by the type VI secretion system (T6SS) in certain pathogenic strains of Escherichia coli (E. coli) that causes apoptosis and contributes to the development of meningitis. The exact toxic consequences of Hcp1 and whether it intensifies the inflammatory response by triggering pyroptosis are yet unknown. Here, utilizing the CRISPR/Cas9 genome editing method, we removed the gene expressing Hcp1 from wild-type E. coli W24 and examined the impact of Hcp1 on E. coli virulence in Kunming (KM) mice. It was found that Hcp1-sufficient E. coli was more lethal, exacerbating acute liver injury (ALI) and acute kidney injury (AKI) or even systemic infections, structural organ damage, and inflammatory factor infiltration. These symptoms were alleviated in mice infected with W24Δhcp1. Additionally, we investigated the molecular mechanism by which Hcp1 worsens AKI and found that pyroptosis is involved, manifested as DNA breaks in many renal tubular epithelial cells. Genes or proteins closely related to pyroptosis are abundantly expressed in the kidney. Most importantly, Hcp1 promotes the activation of the NLRP3 inflammasome and the expression of active caspase-1, thereby cleaving GSDMD-N and accelerating the release of active IL-1β and ultimately leading to pyroptosis. In conclusion, Hcp1 enhances the virulence of E. coli, aggravates ALI and AKI, and promotes the inflammatory response; moreover, Hcp1-induced pyroptosis is one of the molecular mechanisms of AKI.
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Affiliation(s)
- Hao Wang
- College of Food Science and Technology, Yunnan Agricultural University, Kunming 650201, China
| | - Long-Bao Lv
- National Resource Center for Non-Human Primates, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650107, China
| | - Li-Ping Chen
- College of Foreign Languages, Yunnan Agricultural University, Kunming 650201, China
| | - Jin-Long Xiao
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Jue Shen
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Bin Gao
- College of Food Science and Technology, Yunnan Agricultural University, Kunming 650201, China
| | - Jin-Gang Zhao
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Dong-Mei Han
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Bin-Xun Chen
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Shuai Wang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Gen Liu
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Ai-Guo Xin
- National Foot-and-Mouth Disease Para-Reference Laboratory (Kunming), Yunnan Animal Science and Veterinary Institute, Kunming 650224, China
| | - Peng Xiao
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
| | - Hong Gao
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
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23
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Robitaille S, Simmons EL, Verster AJ, McClure EA, Royce DB, Trus E, Swartz K, Schultz D, Nadell CD, Ross BD. Community composition and the environment modulate the population dynamics of type VI secretion in human gut bacteria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.20.529031. [PMID: 36865186 PMCID: PMC9980007 DOI: 10.1101/2023.02.20.529031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Understanding the relationship between the composition of the human gut microbiota and the ecological forces shaping it is of high importance as progress towards therapeutic modulation of the microbiota advances. However, given the inaccessibility of the gastrointestinal tract, our knowledge of the biogeographical and ecological relationships between physically interacting taxa has been limited to date. It has been suggested that interbacterial antagonism plays an important role in gut community dynamics, but in practice the conditions under which antagonistic behavior is favored or disfavored by selection in the gut environment are not well known. Here, using phylogenomics of bacterial isolate genomes and analysis of infant and adult fecal metagenomes, we show that the contact-dependent type VI secretion system (T6SS) is repeatedly lost from the genomes of Bacteroides fragilis in adults compare to infants. Although this result implies a significant fitness cost to the T6SS, but we could not identify in vitro conditions under which such a cost manifests. Strikingly, however, experiments in mice illustrated that the B. fragilis T6SS can be favored or disfavored in the gut environment, depending on the strains and species in the surrounding community and their susceptibility to T6SS antagonism. We use a variety of ecological modeling techniques to explore the possible local community structuring conditions that could underlie the results of our larger scale phylogenomic and mouse gut experimental approaches. The models illustrate robustly that the pattern of local community structuring in space can modulate the extent of interactions between T6SS-producing, sensitive, and resistant bacteria, which in turn control the balance of fitness costs and benefits of performing contact-dependent antagonistic behavior. Taken together, our genomic analyses, in vivo studies, and ecological theory point toward new integrative models for interrogating the evolutionary dynamics of type VI secretion and other predominant modes of antagonistic interaction in diverse microbiomes.
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Affiliation(s)
- Sophie Robitaille
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Emilia L. Simmons
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Adrian J. Verster
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Emily Ann McClure
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Darlene B. Royce
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Evan Trus
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Kerry Swartz
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Daniel Schultz
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
| | - Carey D. Nadell
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Benjamin D. Ross
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH 03755, USA
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24
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Liu M, Zhao MY, Wang H, Wang ZH, Wang Z, Liu Y, Li YP, Dong T, Fu Y. Pesticin-Like Effector VgrG3 cp Targeting Peptidoglycan Delivered by the Type VI Secretion System Contributes to Vibrio cholerae Interbacterial Competition. Microbiol Spectr 2023; 11:e0426722. [PMID: 36625646 PMCID: PMC9927483 DOI: 10.1128/spectrum.04267-22] [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: 10/22/2022] [Accepted: 12/13/2022] [Indexed: 01/11/2023] Open
Abstract
Vibrio cholerae can utilize a type VI secretion system (T6SS) to increase its intra- and interspecies competition. However, much still remains to be understood about the underlying mechanism of this intraspecies competition. In this study, we isolated an environmental V. cholerae strain E1 that lacked the typical virulence factors toxin-coregulated pilus and cholera toxin and that encoded a functional T6SS. We identified an evolved VgrG3 variant with a predicted C-terminal pesticin-like domain in V. cholerae E1, designated VgrG3cp. Using heterologous expression, protein secretion, and peptidoglycan-degrading assays, we demonstrated that VgrG3cp is a T6SS-dependent effector harboring cell wall muramidase activity and that its toxicity can be neutralized by cognate immunity protein TsiV3cp. Site-directed mutagenesis proved that the aspartic acid residue at position 867 is crucial for VgrG3cp-mediated antibacterial activity. Bioinformatic analysis showed that genes encoding VgrG3cp-like homologs are distributed in Vibrio species, are linked with T6SS structural genes and auxiliary genes, and the vgrG3cp-tsiV3cp gene pair of V. cholerae probably evolved from Vibrio anguillarum and Vibrio fluvialis via homologous recombination. Through a time-lapse microscopy assay, we directly determined that cells accumulating VgrG3cp disrupted bacterial division, while the cells continued to increase in size until the loss of membrane potential and cell wall breakage and finally burst. The results of the competitive killing assay showed that VgrG3cp contributes to V. cholerae interspecies competition. Collectively, our study revealed a novel T6SS E-I pair representing a new T6SS toxin family which allows V. cholerae to gain dominance within polymicrobial communities by T6SS. IMPORTANCE The type VI secretion system used by a broad range of Gram-negative bacteria delivers toxic proteins to target adjacent eukaryotic and prokaryotic cells. Diversification of effector proteins determines the complex bacterium-bacterium interactions and impacts the health of hosts and environmental ecosystems in which bacteria reside. This work uncovered an evolved valine-glycine repeat protein G3, carrying a C-terminal pesticin-like domain (VgrG3cp), which has been suggested to harbor cell wall hydrolase activity and is able to affect cell division and the integrity of cell wall structure. Pesticin-like homologs constitute a family of T6SS-associated effectors targeting bacterial peptidoglycan which are distributed in Vibrio species, and genetic loci of them are linked with T6SS structural genes and auxiliary genes. T6SS-delivered VgrG3cp mediated broad-spectrum antibacterial activity for several microorganisms tested, indicating that VgrG3cp-mediated antimicrobial activity is capable of conferring bacteria a competitive advantage over competitors in the same niches.
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Affiliation(s)
- Ming Liu
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Meng-Yu Zhao
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
- The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Heng Wang
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Zeng-Hang Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Zhao Wang
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Ying Liu
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Yin-Peng Li
- The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Tao Dong
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Yang Fu
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
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25
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Irulappan M, Mutreja A, Veeraraghavan B. Genomic surveillance for comprehensive Shigella management. THE LANCET. INFECTIOUS DISEASES 2023; 23:645-647. [PMID: 36731479 DOI: 10.1016/s1473-3099(23)00006-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 01/03/2023] [Indexed: 02/02/2023]
Affiliation(s)
- Madhumathi Irulappan
- Department of Clinical Microbiology, Christian Medical College, Vellore 632004, India
| | - Ankur Mutreja
- Department of Medicine, Addenbrookes Hospital, University of Cambridge, Cambridge, UK
| | - Balaji Veeraraghavan
- Department of Clinical Microbiology, Christian Medical College, Vellore 632004, India.
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26
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Siniagina MN, Laikov AV, Markelova MI, Boulygina EA, Khusnutdinova DR, Abdulkhakov SR, Grigoryeva TV. Competitive ability of <i>Escherichia coli</i> strains in the intestinal microbiota of patients with Crohn's disease and healthy volunteers: physiological, biochemical and genetic characteristics. JOURNAL OF MICROBIOLOGY, EPIDEMIOLOGY AND IMMUNOBIOLOGY 2023. [DOI: 10.36233/0372-9311-192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Introduction. Crohn's disease (CD) is a chronic inflammation of various parts of the gastrointestinal tract with an increased proportion of Escherichia coli. However, the role of E. coli in disease remains unclear.
This study aims to evaluate the competitive abilities of E. coli strains from CD patients and healthy volunteers, and to identify the biochemical and genetic determinants underlying these features.
Materials and methods. The antagonistic activity was assessed by co-cultivation of 11 clinical E. coli strains inhibiting the growth of the K-12, with Enterobacter cloacae, Klebsiella pneumonia and Salmonella enterica. To elucidate the mechanism of antagonistic activity, the evaluation of biochemical properties and a comparative genomic analysis were used.
Results and discussion. Genes of bacteriocin production systems were identified in genomes of 11 strains from CD patients and healthy volunteers active against the E. coli K-12 strain. Three strains from healthy individuals demonstrated activity against several Enterobacteriaceae bacteria. The strains biochemical properties were typical of representatives of E. coli. Strains 1_34_12, active against E. cloacae, and 1_45_11, inhibiting all tested enterobacteria, are phylogenetically related to the laboratory strain K-12. Strain 1_39_1, active against K. pneumonia and S. enterica, is phylogenetically close to the Nissle1917, contains the genes for colibactin biosynthesis and a variant of the fimH gene that increases the adhesive ability of bacteria.
Conclusion. The identified E. coli strains are able to displace Enterobacteriaceae bacteria and can be used to study the bacteria-bacteria and host-bacteria interactions, to understand their role in gut homeostasis and intestinal inflammation.
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27
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Zuo Y, Li C, Yu D, Wang K, Liu Y, Wei Z, Yang Y, Wang Y, Shen X, Zhu L. A Fur-regulated type VI secretion system contributes to oxidative stress resistance and virulence in Yersinia pseudotuberculosis. STRESS BIOLOGY 2023; 3:2. [PMID: 37676351 PMCID: PMC10441874 DOI: 10.1007/s44154-022-00081-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 12/26/2022] [Indexed: 09/08/2023]
Abstract
The type VI secretion system (T6SS) is a widespread protein secretion apparatus deployed by many Gram-negative bacterial species to interact with competitor bacteria, host organisms, and the environment. Yersinia pseudotuberculosis T6SS4 was recently reported to be involved in manganese acquisition; however, the underlying regulatory mechanism still remains unclear. In this study, we discovered that T6SS4 is regulated by ferric uptake regulator (Fur) in response to manganese ions (Mn2+), and this negative regulation of Fur was proceeded by specifically recognizing the promoter region of T6SS4 in Y. pseudotuberculosis. Furthermore, T6SS4 is induced by low Mn2+ and oxidative stress conditions via Fur, acting as a Mn2+-responsive transcriptional regulator to maintain intracellular manganese homeostasis, which plays important role in the transport of Mn2+ for survival under oxidative stress. Our results provide evidence that T6SS4 can enhance the oxidative stress resistance and virulence for Y. pseudotuberculosis. This study provides new insights into the regulation of T6SS4 via the Mn2+-dependent transcriptional regulator Fur, and expands our knowledge of the regulatory mechanisms and functions of T6SS from Y. pseudotuberculosis.
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Affiliation(s)
- Yuxin Zuo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Changfu Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Danyang Yu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Kenan Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yuqi Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Zhiyan Wei
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yantao Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yao Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Lingfang Zhu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China.
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28
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Abstract
The major function of the mammalian immune system is to prevent and control infections caused by enteropathogens that collectively have altered human destiny. In fact, as the gastrointestinal tissues are the major interface of mammals with the environment, up to 70% of the human immune system is dedicated to patrolling them The defenses are multi-tiered and include the endogenous microflora that mediate colonization resistance as well as physical barriers intended to compartmentalize infections. The gastrointestinal tract and associated lymphoid tissue are also protected by sophisticated interleaved arrays of active innate and adaptive immune defenses. Remarkably, some bacterial enteropathogens have acquired an arsenal of virulence factors with which they neutralize all these formidable barriers to infection, causing disease ranging from mild self-limiting gastroenteritis to in some cases devastating human disease.
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Affiliation(s)
- Micah J. Worley
- Department of Biology, University of Louisville, Louisville, Kentucky, USA,CONTACT Micah J. Worley Department of Biology, University of Louisville, 139 Life Sciences Bldg, Louisville, Kentucky, USA
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29
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A secreted effector with a dual role as a toxin and as a transcriptional factor. Nat Commun 2022; 13:7779. [PMID: 36522324 PMCID: PMC9755527 DOI: 10.1038/s41467-022-35522-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
Bacteria have evolved multiple secretion systems for delivering effector proteins into the cytosol of neighboring cells, but the roles of many of these effectors remain unknown. Here, we show that Yersinia pseudotuberculosis secretes an effector, CccR, that can act both as a toxin and as a transcriptional factor. The effector is secreted by a type VI secretion system (T6SS) and can enter nearby cells of the same species and other species (such as Escherichia coli) via cell-cell contact and in a contact-independent manner. CccR contains an N-terminal FIC domain and a C-terminal DNA-binding domain. In Y. pseudotuberculosis cells, CccR inhibits its own expression by binding through its DNA-binding domain to the cccR promoter, and affects the expression of other genes through unclear mechanisms. In E. coli cells, the FIC domain of CccR AMPylates the cell division protein FtsZ, inducing cell filamentation and growth arrest. Thus, our results indicate that CccR has a dual role, modulating gene expression in neighboring cells of the same species, and inhibiting the growth of competitors.
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Adsit FG, Randall TA, Locklear J, Kurtz DM. The emergence of the tetrathionate reductase operon in the Escherichia coli/Shigella pan-genome. Microbiologyopen 2022; 11:e1333. [PMID: 36479628 PMCID: PMC9638481 DOI: 10.1002/mbo3.1333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/18/2022] [Accepted: 10/20/2022] [Indexed: 11/09/2022] Open
Abstract
Escherichia coli pathogenic variants (pathovars) are generally characterized by defined virulence traits and are susceptible to the evolution of hybridized identities due to the considerable plasticity of the E. coli genome. We have isolated a strain from a purified diet intended for research animals that further demonstrates the ability of E. coli to acquire novel genetic elements leading potentially to emergent new pathovars. Utilizing next generation sequencing to obtain a whole genome profile, we report an atypical strain of E. coli, EcoFA807-17, possessing a tetrathionate reductase (ttr) operon, which enables the utilization of tetrathionate as an electron acceptor, thus facilitating respiration in anaerobic environments such as the mammalian gut. The ttr operon is a potent virulence factor for several enteric pathogens, most prominently Salmonella enterica. However, the presence of chromosomally integrated tetrathionate reductase genes does not appear to have been previously reported in wild-type E. coli or Shigella. Accordingly, it is possible that the appearance of this virulence factor may signal the evolution of new mechanisms of pathogenicity in E. coli and Shigella and may potentially alter the effectiveness of existing assays using tetrathionate reductase as a unique marker for the detection of Salmonella enterica.
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Affiliation(s)
- Floyd G. Adsit
- Quality Assurance Laboratory (QAL), Comparative Medicine Branch (CMB)National Institute of Environmental Health Sciences (NIEHS)DurhamNorth CarolinaUSA
| | - Thomas A. Randall
- Integrative BioinformaticsNational Institute of Environmental Health Sciences (NIEHS)DurhamNorth CarolinaUSA
| | - Jacqueline Locklear
- Quality Assurance Laboratory (QAL), Comparative Medicine Branch (CMB)National Institute of Environmental Health Sciences (NIEHS)DurhamNorth CarolinaUSA
| | - David M. Kurtz
- Quality Assurance Laboratory (QAL), Comparative Medicine Branch (CMB)National Institute of Environmental Health Sciences (NIEHS)DurhamNorth CarolinaUSA
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Role of Klebsiella pneumoniae Type VI secretion system (T6SS) in long-term gastrointestinal colonization. Sci Rep 2022; 12:16968. [PMID: 36216848 PMCID: PMC9550808 DOI: 10.1038/s41598-022-21396-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/27/2022] [Indexed: 12/29/2022] Open
Abstract
Type VI secretion systems (T6SS), recently described in hypervirulent K. pneumoniae (hvKp) strains, are involved in bacterial warfare but their role in classical clinical strains (cKp) has been little investigated. In silico analysis indicated the presence of T6SS clusters (from zero to four), irrespective of the strains origin or virulence, with a high prevalence in the K. pneumoniae species (98%). In the strain CH1157, two T6SS-apparented pathogenicity islands were detected, T6SS-1 and -2, harboring a phospholipase-encoding gene (tle1) and a potential new effector-encoding gene named tke (Type VI Klebsiella effector). Tle1 expression in Escherichia coli periplasm affected cell membrane permeability. T6SS-1 isogenic mutants colonized the highest gastrointestinal tract of mice less efficiently than their parental strain, at long term. Comparative analysis of faecal 16S sequences indicated that T6SS-1 impaired the microbiota richness and its resilience capacity. Oscillospiraceae family members could be specific competitors for the long-term gut establishment of K. pneumoniae.
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Alphonse N, Wanford JJ, Voak AA, Gay J, Venkhaya S, Burroughs O, Mathew S, Lee T, Evans SL, Zhao W, Frowde K, Alrehaili A, Dickenson RE, Munk M, Panina S, Mahmood IF, Llorian M, Stanifer ML, Boulant S, Berchtold MW, Bergeron JRC, Wack A, Lesser CF, Odendall C. A family of conserved bacterial virulence factors dampens interferon responses by blocking calcium signaling. Cell 2022; 185:2354-2369.e17. [PMID: 35568036 PMCID: PMC9596379 DOI: 10.1016/j.cell.2022.04.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 03/22/2022] [Accepted: 04/20/2022] [Indexed: 02/06/2023]
Abstract
Interferons (IFNs) induce an antimicrobial state, protecting tissues from infection. Many viruses inhibit IFN signaling, but whether bacterial pathogens evade IFN responses remains unclear. Here, we demonstrate that the Shigella OspC family of type-III-secreted effectors blocks IFN signaling independently of its cell death inhibitory activity. Rather, IFN inhibition was mediated by the binding of OspC1 and OspC3 to the Ca2+ sensor calmodulin (CaM), blocking CaM kinase II and downstream JAK/STAT signaling. The growth of Shigella lacking OspC1 and OspC3 was attenuated in epithelial cells and in a murine model of infection. This phenotype was rescued in both models by the depletion of IFN receptors. OspC homologs conserved in additional pathogens not only bound CaM but also inhibited IFN, suggesting a widespread virulence strategy. These findings reveal a conserved but previously undescribed molecular mechanism of IFN inhibition and demonstrate the critical role of Ca2+ and IFN targeting in bacterial pathogenesis.
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Affiliation(s)
- Noémie Alphonse
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK; Immunoregulation Laboratory, Francis Crick Institute, London, UK
| | - Joseph J Wanford
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Andrew A Voak
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Jack Gay
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Shayla Venkhaya
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Owen Burroughs
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Sanjana Mathew
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Truelian Lee
- Center for Bacterial Pathogenesis, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Sasha L Evans
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK
| | - Weiting Zhao
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Kyle Frowde
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Abrar Alrehaili
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Ruth E Dickenson
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Mads Munk
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Svetlana Panina
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ishraque F Mahmood
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Miriam Llorian
- Bioinformatics and Biostatistics, The Francis Crick Institute, London, UK
| | - Megan L Stanifer
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Steeve Boulant
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
| | | | - Julien R C Bergeron
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK
| | - Andreas Wack
- Immunoregulation Laboratory, Francis Crick Institute, London, UK
| | - Cammie F Lesser
- Center for Bacterial Pathogenesis, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Charlotte Odendall
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK.
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Clarkson KA, Porter CK, Talaat KR, Kapulu MC, Chen WH, Frenck RW, Bourgeois AL, Kaminski RW, Martin LB. Shigella-Controlled Human Infection Models: Current and Future Perspectives. Curr Top Microbiol Immunol 2022. [PMID: 35616717 DOI: 10.1007/82_2021_248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Shigella-controlled human infection models (CHIMs) are an invaluable tool utilized by the vaccine community to combat one of the leading global causes of infectious diarrhea, which affects infants, children and adults regardless of socioeconomic status. The impact of shigellosis disproportionately affects children in low- and middle-income countries (LMICs) resulting in cognitive and physical stunting, perpetuating a cycle that must be halted. Shigella-CHIMs not only facilitate the early evaluation of enteric countermeasures and up-selection of the most promising products but also provide insight into mechanisms of infection and immunity that are not possible utilizing animal models or in vitro systems. The greater understanding of shigellosis obtained in CHIMs builds and empowers the development of new generation solutions to global health issues which are unattainable in the conventional laboratory and clinical settings. Therefore, refining, mining and expansion of safe and reproducible infection models hold the potential to create effective means to end diarrheal disease and associated co-morbidities associated with Shigella infection.
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Affiliation(s)
- Kristen A Clarkson
- Department of Diarrheal Disease Research, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Chad K Porter
- Enteric Disease Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Kawsar R Talaat
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, 624 North Broadway Street Hampton House, Baltimore, MD, 21205, USA
| | - Melissa C Kapulu
- Department of Biosciences, KEMRI-Wellcome Trust Research Programme, Kilifi County Hospital, Off Bofa Road, Kilifi, 80108, Kenya
| | - Wilbur H Chen
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD, 21201, USA
| | - Robert W Frenck
- Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA
| | - A Louis Bourgeois
- PATH Center for Vaccine Innovation and Access, 455 Massachusetts Avenue NW, Washington, DC, 20001, USA
| | - Robert W Kaminski
- Department of Diarrheal Disease Research, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Laura B Martin
- GSK Vaccines Institute for Global Health, Via Fiorentina 1, 53100, Siena, Italy.
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An Experimental Adult Zebrafish Model for Shigella Pathogenesis, Transmission, and Vaccine Efficacy Studies. Microbiol Spectr 2022; 10:e0034722. [PMID: 35604149 PMCID: PMC9241715 DOI: 10.1128/spectrum.00347-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shigellosis has been a menace to society for ages. The absence of an effective vaccine against Shigella, improper sanitation, and unhygienic use of food and water allow the disease to flourish. Shigella can also be transmitted via natural water bodies. In the absence of a good animal model, the actual nature of pathogenesis and transmission remains unclear. Zebrafish larvae have previously been described as a model for Shigella pathogenesis. However, larval fish lack a mature intestinal microbiota and immune system. Here, the adult zebrafish was assessed as a potential model for Shigella pathogenesis. Their well-developed innate and adaptive immune responses mimic the mammalian immune system. Shigella showed a clear dose-, time-, and temperature-dependent colonization of the adult zebrafish gut. Efficacy of a three-dose immunization regime was tested using bath immunization with heat-killed trivalent Shigella immunogen. The present study demonstrates the efficacy of an adult zebrafish model for pathogenesis, transmission, and vaccine efficacy studies. IMPORTANCE Shigellosis is a diarrheal disease that is prevalent in developing countries and especially dangerous in young children. Currently, animal models for shigellosis are unable to model some aspects of the infectious cycle. Here, we describe a new shigellosis model in adult zebrafish, an increasingly common model organism for studying bacterial pathogens. The zebrafish model can be used to study Shigella colonization, transmission, and immune responses, as well as test vaccine efficacy.
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35
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Serapio-Palacios A, Woodward SE, Vogt SL, Deng W, Creus-Cuadros A, Huus KE, Cirstea M, Gerrie M, Barcik W, Yu H, Finlay BB. Type VI secretion systems of pathogenic and commensal bacteria mediate niche occupancy in the gut. Cell Rep 2022; 39:110731. [PMID: 35476983 DOI: 10.1016/j.celrep.2022.110731] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 02/04/2022] [Accepted: 04/01/2022] [Indexed: 12/18/2022] Open
Abstract
The type VI secretion system (T6SS) is a contractile nanomachine widely distributed among pathogenic and commensal Gram-negative bacteria. The T6SS is used for inter-bacterial competition to directly kill competing species; however, its importance during bacterial infection in vivo remains poorly understood. We report that the murine pathogen Citrobacter rodentium, used as a model for human pathogenic Escherichia coli, harbors two functional T6SSs. C. rodentium employs its T6SS-1 to colonize the murine gastrointestinal tract by targeting commensal Enterobacteriaceae. We identify VgrG1 as a C. rodentium T6SS antibacterial effector, which exhibits toxicity in E. coli. Conversely, commensal prey species E. coli Mt1B1 employs two T6SSs of its own to counter C. rodentium colonization. Collectively, these data demonstrate that the T6SS is a potent weapon during bacterial competition and is used by both invading pathogens and resident microbiota to fight for a niche in the hostile gut environment.
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Affiliation(s)
- Antonio Serapio-Palacios
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Sarah E Woodward
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Stefanie L Vogt
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Wanyin Deng
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Anna Creus-Cuadros
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Kelsey E Huus
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Mihai Cirstea
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Madeleine Gerrie
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Weronika Barcik
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada
| | - Hongbing Yu
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - B Brett Finlay
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, BC V6T 1Z3, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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36
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Hou K, Wu ZX, Chen XY, Wang JQ, Zhang D, Xiao C, Zhu D, Koya JB, Wei L, Li J, Chen ZS. Microbiota in health and diseases. Signal Transduct Target Ther 2022; 7:135. [PMID: 35461318 PMCID: PMC9034083 DOI: 10.1038/s41392-022-00974-4] [Citation(s) in RCA: 563] [Impact Index Per Article: 281.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 03/11/2022] [Accepted: 03/15/2022] [Indexed: 02/07/2023] Open
Abstract
The role of microbiota in health and diseases is being highlighted by numerous studies since its discovery. Depending on the localized regions, microbiota can be classified into gut, oral, respiratory, and skin microbiota. The microbial communities are in symbiosis with the host, contributing to homeostasis and regulating immune function. However, microbiota dysbiosis can lead to dysregulation of bodily functions and diseases including cardiovascular diseases (CVDs), cancers, respiratory diseases, etc. In this review, we discuss the current knowledge of how microbiota links to host health or pathogenesis. We first summarize the research of microbiota in healthy conditions, including the gut-brain axis, colonization resistance and immune modulation. Then, we highlight the pathogenesis of microbiota dysbiosis in disease development and progression, primarily associated with dysregulation of community composition, modulation of host immune response, and induction of chronic inflammation. Finally, we introduce the clinical approaches that utilize microbiota for disease treatment, such as microbiota modulation and fecal microbial transplantation.
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Affiliation(s)
- Kaijian Hou
- Department of Endocrine and Metabolic Diseases, Longhu Hospital, The First Affiliated Hospital of Medical College of Shantou University, Shantou, Guangdong, 515000, China
| | - Zhuo-Xun Wu
- Department of Pharmaceutical Sciences, Institute for Biotechnology, College of Pharmacy and Health Sciences, St. John's University, Queens, NY, 11439, USA
| | - Xuan-Yu Chen
- Department of Pharmaceutical Sciences, Institute for Biotechnology, College of Pharmacy and Health Sciences, St. John's University, Queens, NY, 11439, USA
| | - Jing-Quan Wang
- Department of Pharmaceutical Sciences, Institute for Biotechnology, College of Pharmacy and Health Sciences, St. John's University, Queens, NY, 11439, USA
| | - Dongya Zhang
- Microbiome Research Center, Moon (Guangzhou) Biotech Ltd, Guangzhou, 510535, China
| | - Chuanxing Xiao
- Department of Endocrine and Metabolic Diseases, Longhu Hospital, The First Affiliated Hospital of Medical College of Shantou University, Shantou, Guangdong, 515000, China
| | - Dan Zhu
- Department of Endocrine and Metabolic Diseases, Longhu Hospital, The First Affiliated Hospital of Medical College of Shantou University, Shantou, Guangdong, 515000, China
| | - Jagadish B Koya
- Department of Pharmaceutical Sciences, Institute for Biotechnology, College of Pharmacy and Health Sciences, St. John's University, Queens, NY, 11439, USA
| | - Liuya Wei
- School of Pharmacy, Weifang Medical University, Weifang, Shandong, 261053, China
| | - Jilin Li
- Department of Cardiovascular, The Second Affiliated Hospital of Medical College of Shantou University, Shantou, Guangdong, 515000, China
| | - Zhe-Sheng Chen
- Department of Pharmaceutical Sciences, Institute for Biotechnology, College of Pharmacy and Health Sciences, St. John's University, Queens, NY, 11439, USA
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Grzymajlo K. The Game for Three: Salmonella–Host–Microbiota Interaction Models. Front Microbiol 2022; 13:854112. [PMID: 35516427 PMCID: PMC9062650 DOI: 10.3389/fmicb.2022.854112] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 03/11/2022] [Indexed: 11/16/2022] Open
Abstract
Colonization of the gastrointestinal (GI) tract by enteric pathogens occurs in a context strongly determined by host-specific gut microbiota, which can significantly affect the outcome of infection. The complex gameplay between the trillions of microbes that inhabit the GI tract, the host, and the infecting pathogen defines a specific triangle of interaction; therefore, a complete model of infection should consider all of these elements. Many different infection models have been developed to explain the complexity of these interactions. This review sheds light on current knowledge, along with the strengths and limitations of in vitro and in vivo models utilized in the study of Salmonella–host–microbiome interactions. These models range from the simplest experiment simulating environmental conditions using dedicated growth media through in vitro interaction with cell lines and 3-D organoid structure, and sophisticated “gut on a chip” systems, ending in various animal models. Finally, the challenges facing this field of research and the important future directions are outlined.
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38
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Diarrheal disease and gut microbiome. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 192:149-177. [DOI: 10.1016/bs.pmbts.2022.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Gallegos-Monterrosa R, Coulthurst SJ. The ecological impact of a bacterial weapon: microbial interactions and the Type VI secretion system. FEMS Microbiol Rev 2021; 45:fuab033. [PMID: 34156081 PMCID: PMC8632748 DOI: 10.1093/femsre/fuab033] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 06/20/2021] [Indexed: 12/13/2022] Open
Abstract
Bacteria inhabit all known ecological niches and establish interactions with organisms from all kingdoms of life. These interactions are mediated by a wide variety of mechanisms and very often involve the secretion of diverse molecules from the bacterial cells. The Type VI secretion system (T6SS) is a bacterial protein secretion system that uses a bacteriophage-like machinery to secrete a diverse array of effectors, usually translocating them directly into neighbouring cells. These effectors display toxic activity in the recipient cell, making the T6SS an effective weapon during inter-bacterial competition and interactions with eukaryotic cells. Over the last two decades, microbiology research has experienced a shift towards using systems-based approaches to study the interactions between diverse organisms and their communities in an ecological context. Here, we focus on this aspect of the T6SS. We consider how our perspective of the T6SS has developed and examine what is currently known about the impact that bacteria deploying the T6SS can have in diverse environments, including niches associated with plants, insects and mammals. We consider how T6SS-mediated interactions can affect host organisms by shaping their microbiota, as well as the diverse interactions that can be established between different microorganisms through the deployment of this versatile secretion system.
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Affiliation(s)
| | - Sarah J Coulthurst
- School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
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40
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Lin J, Xu L, Yang J, Wang Z, Shen X. Beyond dueling: roles of the type VI secretion system in microbiome modulation, pathogenesis and stress resistance. STRESS BIOLOGY 2021; 1:11. [PMID: 37676535 PMCID: PMC10441901 DOI: 10.1007/s44154-021-00008-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 08/09/2021] [Indexed: 09/08/2023]
Abstract
Bacteria inhabit diverse and dynamic environments, where nutrients may be limited and toxic chemicals can be prevalent. To adapt to these stressful conditions, bacteria have evolved specialized protein secretion systems, such as the type VI secretion system (T6SS) to facilitate their survival. As a molecular syringe, the T6SS expels various effectors into neighboring bacterial cells, eukaryotic cells, or the extracellular environment. These effectors improve the competitive fitness and environmental adaption of bacterial cells. Although primarily recognized as antibacterial weapons, recent studies have demonstrated that T6SSs have functions beyond interspecies competition. Here, we summarize recent research on the role of T6SSs in microbiome modulation, pathogenesis, and stress resistance.
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Affiliation(s)
- Jinshui Lin
- Shaanxi Key Laboratory of Chinese Jujube, College of Life Sciences, Yan'an University, Yan'an, Shaanxi, 716000, People's Republic of China
| | - Lei Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China
| | - Jianshe Yang
- Shaanxi Key Laboratory of Chinese Jujube, College of Life Sciences, Yan'an University, Yan'an, Shaanxi, 716000, People's Republic of China
| | - Zhuo Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China.
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41
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Heilbronner S, Krismer B, Brötz-Oesterhelt H, Peschel A. The microbiome-shaping roles of bacteriocins. Nat Rev Microbiol 2021; 19:726-739. [PMID: 34075213 DOI: 10.1038/s41579-021-00569-w] [Citation(s) in RCA: 129] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2021] [Indexed: 02/05/2023]
Abstract
The microbiomes on human body surfaces affect health in multiple ways. They include not only commensal or mutualistic bacteria but also potentially pathogenic bacteria, which can enter sterile tissues to cause invasive infection. Many commensal bacteria produce small antibacterial molecules termed bacteriocins that have the capacity to eliminate specific colonizing pathogens; as such, bacteriocins have attracted increased attention as potential microbiome-editing tools. Metagenome-based and activity-based screening approaches have strongly expanded our knowledge of the abundance and diversity of bacteriocin biosynthetic gene clusters and the properties of a continuously growing list of bacteriocin classes. The dynamic acquisition, diversification or loss of bacteriocin genes can shape the fitness of a bacterial strain that is in competition with bacteriocin-susceptible bacteria. However, a bacteriocin can only provide a competitive advantage if its fitness benefit exceeds the metabolic cost of production, if it spares crucial mutualistic partner strains and if major competitors cannot develop resistance. In contrast to most currently available antibiotics, many bacteriocins have only narrow activity ranges and could be attractive agents for precision therapy and prevention of infections. A common scientific strategy involving multiple disciplines is needed to uncover the immense potential of microbiome-shaping bacteriocins.
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Affiliation(s)
- Simon Heilbronner
- Interfaculty Institute of Microbiology and Infection Medicine, Department of Infection Biology, University of Tübingen, Tübingen, Germany. .,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, University of Tübingen, Tübingen, Germany.
| | - Bernhard Krismer
- Interfaculty Institute of Microbiology and Infection Medicine, Department of Infection Biology, University of Tübingen, Tübingen, Germany.,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, University of Tübingen, Tübingen, Germany
| | - Heike Brötz-Oesterhelt
- Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, University of Tübingen, Tübingen, Germany.,Interfaculty Institute of Microbiology and Infection Medicine, Department of Microbial Bioactive Compounds, University of Tübingen, Tübingen, Germany
| | - Andreas Peschel
- Interfaculty Institute of Microbiology and Infection Medicine, Department of Infection Biology, University of Tübingen, Tübingen, Germany. .,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, University of Tübingen, Tübingen, Germany.
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Abstract
Commensal microbes in animal guts often help to exclude bacterial pathogens. In honey bees, perturbing or depleting the gut microbiota increases host mortality rates upon challenge with the opportunistic pathogen Serratia marcescens, suggesting antagonism between S. marcescens and one or more members of the bee gut microbiota. In laboratory culture, S. marcescens uses a type VI secretion system (T6SS) to kill bacterial competitors, but the role of this T6SS within hosts is unknown. Using infection assays, we determined how the microbiota impacts the abundance and persistence of S. marcescens in the gut and visualized colocalization of S. marcescens with specific community members in situ. Using T6SS-deficient S. marcescens strains, we measured T6SS-dependent killing of gut isolates in vitro and compared the persistence of mutant and wild-type strains in the gut. We found that S. marcescens is rapidly eliminated in the presence of the microbiota but persists in microbiota-free guts. Protection is reduced in monocolonized and antibiotic-treated bees, possibly because different symbionts occupy distinct niches. Serratia marcescens uses a T6SS to antagonize Escherichia coli and other S. marcescens strains but shows limited ability to kill bee symbionts. Furthermore, wild-type and T6SS-deficient S. marcescens strains achieved similar abundance and persistence in bee guts. Thus, an intact gut microbiota offers robust protection against this common pathogen, whose T6SSs do not confer the ability to compete with commensal species. IMPORTANCE Bacteria living within guts of animals can provide protection against infection by pathogens. Some pathogens have been shown to use a molecular weapon known as a T6SS to kill beneficial bacteria during invasion of the mouse gut. In this study, we examined how bacteria native to the honey bee gut work together to exclude the opportunistic pathogen Serratia marcescens. Although S. marcescens has a T6SS that can kill bacteria, bee gut bacteria seem resistant to its effects. This limitation may partially explain why ingestion of S. marcescens is rarely lethal to insects with healthy gut communities.
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43
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Abstract
The gut microbiota plays a crucial role in susceptibility to enteric pathogens, including Citrobacter rodentium, a model extracellular mouse pathogen that colonizes the colonic mucosa. C. rodentium infection outcomes vary between mouse strains, with C57BL/6 and C3H/HeN mice clearing and succumbing to the infection, respectively. Kanamycin (Kan) treatment at the peak of C57BL/6 mouse infection with Kan-resistant C. rodentium resulted in relocalization of the pathogen from the colonic mucosa and cecum to solely the cecal luminal contents; cessation of the Kan treatment resulted in rapid clearance of the pathogen. We now show that in C3H/HeN mice, following Kan-induced displacement of C. rodentium to the cecum, the pathogen stably colonizes the cecal lumens of 65% of the mice in the absence of continued antibiotic treatment, a phenomenon that we term antibiotic-induced bacterial commensalization (AIBC). AIBC C. rodentium was well tolerated by the host, which showed few signs of inflammation; passaged AIBC C. rodentium robustly infected naive C3H/HeN mice, suggesting that the AIBC state is transient and did not select for genetically avirulent C. rodentium mutants. Following withdrawal of antibiotic treatment, 35% of C3H/HeN mice were able to prevent C. rodentium commensalization in the gut lumen. These mice presented a bloom of a commensal species, Citrobacter amalonaticus, which inhibited the growth of C. rodentiumin vitro in a contact-dependent manner and the luminal growth of AIBC C. rodentiumin vivo. Overall, our data suggest that commensal species can confer colonization resistance to closely related pathogenic species.
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Human commensal gut Proteobacteria withstand type VI secretion attacks through immunity protein-independent mechanisms. Nat Commun 2021; 12:5751. [PMID: 34599171 PMCID: PMC8486750 DOI: 10.1038/s41467-021-26041-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 09/13/2021] [Indexed: 12/26/2022] Open
Abstract
While the major virulence factors for Vibrio cholerae, the cause of the devastating diarrheal disease cholera, have been extensively studied, the initial intestinal colonization of the bacterium is not well understood because non-human adult animals are refractory to its colonization. Recent studies suggest the involvement of an interbacterial killing device known as the type VI secretion system (T6SS). Here, we tested the T6SS-dependent interaction of V. cholerae with a selection of human gut commensal isolates. We show that the pathogen efficiently depleted representative genera of the Proteobacteria in vitro, while members of the Enterobacter cloacae complex and several Klebsiella species remained unaffected. We demonstrate that this resistance against T6SS assaults was mediated by the production of superior T6SS machinery or a barrier exerted by group I capsules. Collectively, our data provide new insights into immunity protein-independent T6SS resistance employed by the human microbiota and colonization resistance in general.
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45
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Sibinelli-Sousa S, de Araújo-Silva AL, Hespanhol JT, Bayer-Santos E. Revisiting the steps of Salmonella gut infection with a focus on antagonistic interbacterial interactions. FEBS J 2021; 289:4192-4211. [PMID: 34546626 DOI: 10.1111/febs.16211] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/12/2021] [Accepted: 09/20/2021] [Indexed: 12/20/2022]
Abstract
A commensal microbial community is established in the mammalian gut during its development, and these organisms protect the host against pathogenic invaders. The hallmark of noninvasive Salmonella gut infection is the induction of inflammation via effector proteins secreted by the type III secretion system, which modulate host responses to create a new niche in which the pathogen can overcome the colonization resistance imposed by the microbiota. Several studies have shown that endogenous microbes are important to control Salmonella infection by competing for resources. However, there is limited information about antimicrobial mechanisms used by commensals and pathogens during these in vivo disputes for niche control. This review aims to revisit the steps that Salmonella needs to overcome during gut colonization-before and after the induction of inflammation-to achieve an effective infection. We focus on a series of reported and hypothetical antagonistic interbacterial interactions in which both contact-independent and contact-dependent mechanisms might define the outcome of the infection.
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Affiliation(s)
| | | | - Julia Takuno Hespanhol
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Brazil
| | - Ethel Bayer-Santos
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Brazil
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46
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Cassan FD, Coniglio A, Amavizca E, Maroniche G, Cascales E, Bashan Y, de-Bashan LE. The Azospirillum brasilense type VI secretion system promotes cell aggregation, biocontrol protection against phytopathogens and attachment to the microalgae Chlorella sorokiniana. Environ Microbiol 2021; 23:6257-6274. [PMID: 34472164 DOI: 10.1111/1462-2920.15749] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 08/25/2021] [Accepted: 08/28/2021] [Indexed: 01/26/2023]
Abstract
The plant-growth-promoting bacterium Azospirillum brasilense is able to associate with the microalgae Chlorella sorokiniana. Attachment of A. brasilense increases the metabolic performances of the microalgae. Recent genome analyses have revealed that the A. brasilense Az39 genome contains two complete sets of genes encoding type VI secretion systems (T6SS), including the T6SS1 that is induced by the indole-3-acetic acid (IAA) phytohormone. The T6SS is a multiprotein machine, widespread in Gram-negative bacteria, that delivers protein effectors in both prokaryotic and eukaryotic cells. Here we show that the A. brasilense T6SS is required for Chlorella-Azospirillum synthetic mutualism. Our data demonstrate that the T6SS is an important determinant to promote production of lipids, carbohydrates and photosynthetic pigments by the microalgae. We further show that this is likely due to the role of the T6SS during the attachment stage and for the production of IAA phytohormones. Finally, we demonstrate that the A. brasilense T6SS provides antagonistic activities against a number of plant pathogens such as Agrobacterium, Pectobacterium, Dickeya and Ralstonia species in vitro, suggesting that, in addition to promoting growth, A. brasilense might confer T6SS-dependent bio-control protection to microalgae and plants against bacterial pathogens.
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Affiliation(s)
- Fabricio D Cassan
- Laboratorio de Fisiología Vegetal y de la interacción Planta-Microorganismo, Instituto de Investigaciones Agrobiotecnológicas (INIAB), Universidad Nacional de Río Cuarto, Córdoba, Argentina
| | - Anahí Coniglio
- Laboratorio de Fisiología Vegetal y de la interacción Planta-Microorganismo, Instituto de Investigaciones Agrobiotecnológicas (INIAB), Universidad Nacional de Río Cuarto, Córdoba, Argentina
| | - Edgar Amavizca
- Environmental Microbiology Group, Northwestern Center for Biological Research (CIBNOR), La Paz, Mexico
| | - Guillermo Maroniche
- Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata, Buenos Aires, Argentina
| | - Eric Cascales
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Aix-Marseille Université - CNRS UMR7255, Marseille, France
| | - Yoav Bashan
- Environmental Microbiology Group, Northwestern Center for Biological Research (CIBNOR), La Paz, Mexico.,The Bashan Institute of Science, Auburn, AL, USA
| | - Luz E de-Bashan
- Environmental Microbiology Group, Northwestern Center for Biological Research (CIBNOR), La Paz, Mexico.,The Bashan Institute of Science, Auburn, AL, USA.,Department of Entomology and Plant Pathology, 301 Funchess Hall, Auburn University, Auburn, AL, USA
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47
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Formylglycine-generating enzyme-like proteins constitute a novel family of widespread type VI secretion system immunity proteins. J Bacteriol 2021; 203:e0028121. [PMID: 34398661 DOI: 10.1128/jb.00281-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Competition is a critical aspect of bacterial life, as it enables niche establishment and facilitates the acquisition of essential nutrients. Warfare between Gram-negative bacteria is largely mediated by the type VI secretion system (T6SS), a dynamic nanoweapon that delivers toxic effector proteins from an attacking cell to adjacent bacteria in a contact-dependent manner. Effector-encoding bacteria prevent self-intoxication and kin cell killing by the expression of immunity proteins, which prevent effector toxicity by specifically binding their cognate effector and either occluding its active site or preventing structural rearrangements necessary for effector activation. In this study, we investigate Tsi3, a previously uncharacterized T6SS immunity protein present in multiple strains of the human pathogen Acinetobacter baumannii. We show that Tsi3 is the cognate immunity protein of the antibacterial effector of unknown function Tse3. Our bioinformatic analyses indicate that Tsi3 homologs are widespread among Gram-negative bacteria, often encoded within T6SS effector-immunity modules. Surprisingly, we found that Tsi3 homologs are predicted to possess a characteristic formylglycine-generating enzyme (FGE) domain, which is present in various enzymatic proteins. Our data shows that Tsi3-mediated immunity is dependent on Tse3-Tsi3 protein-protein interactions and that Tsi3 homologs from various bacteria do not provide immunity against non-kin Tse3. Thus, we conclude that Tsi3 homologs are unlikely to be functional enzymes. Collectively, our work identifies FGE domain-containing proteins as important mediators of immunity against T6SS attacks and indicates that the FGE domain can be co-opted as a scaffold in multiple proteins to carry out diverse functions. Importance Despite the wealth of knowledge on the diversity of biochemical activities carried out by T6SS effectors, comparably little is known about the various strategies bacteria employ to prevent susceptibility to T6SS-dependent bacterial killing. Our work establishes a novel family of T6SS immunity proteins with a characteristic FGE domain. This domain is present in enzymatic proteins with various catalytic activities. Our characterization of Tsi3 expands the known functions carried out by FGE-like proteins to include defense during T6SS-mediated bacterial warfare. Moreover, it highlights the evolution of FGE domain-containing proteins to carry out diverse biological functions.
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48
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The Vibrio cholerae Type Six Secretion System Is Dispensable for Colonization but Affects Pathogenesis and the Structure of Zebrafish Intestinal Microbiome. Infect Immun 2021; 89:e0015121. [PMID: 34097462 DOI: 10.1128/iai.00151-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Zebrafish (Danio rerio) are an attractive model organism for a variety of scientific studies, including host-microbe interactions. The organism is particularly useful for the study of aquatic microbes that can colonize vertebrate hosts, including Vibrio cholerae, an intestinal pathogen. V. cholerae must colonize the intestine of an exposed host for pathogenicity to occur. While numerous studies have explored various aspects of the pathogenic effects of V. cholerae on zebrafish and other model organisms, few, if any, have examined how a V. cholerae infection alters the resident intestinal microbiome and the role of the type six secretion system (T6SS) in that process. In this study, 16S rRNA gene sequencing was utilized to investigate how strains of V. cholerae both with and without the T6SS alter the aforementioned microbial profiles following an infection. V. cholerae infection induced significant changes in the zebrafish intestinal microbiome, and while not necessary for colonization, the T6SS was important for inducing mucin secretion, a marker for diarrhea. Additional salient differences to the microbiome were observed based on the presence or absence of the T6SS in the V. cholerae utilized for challenging the zebrafish hosts. We conclude that V. cholerae significantly modulates the zebrafish intestinal microbiome to enable colonization and that the T6SS is important for pathogenesis induced by the examined V. cholerae strains. Furthermore, the presence or absence of T6SS differentially and significantly affected the composition and structure of the intestinal microbiome, with an increased abundance of other Vibrio bacteria observed in the absence of V. cholerae T6SS.
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49
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Inhibiting Type VI Secretion System Activity with a Biomimetic Peptide Designed To Target the Baseplate Wedge Complex. mBio 2021; 12:e0134821. [PMID: 34372705 PMCID: PMC8406304 DOI: 10.1128/mbio.01348-21] [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: 12/26/2022] Open
Abstract
Human health is threatened by bacterial infections that are increasingly resistant to multiple drugs. A recently emerged strategy consists of disarming pathogenic bacteria by targeting and blocking their virulence factors. The type VI secretion system (T6SS) is a widespread secretion nanomachine encoded and employed by pathogenic strains to establish their virulence process during host invasion. Given the conservation of T6SS in several human bacterial pathogens, the discovery of an effective broad-spectrum T6SS virulence blocker represents an attractive target for development of antivirulence therapies. Here, we identified and validated a protein-protein interaction interface, TssK-TssG, as a key factor in the assembly of the T6SS baseplate (BP) complex in the pathogen enteroaggregative Escherichia coli (EAEC). In silico and biochemical studies revealed that the determinants of the interface are broadly conserved among pathogenic species, suggesting a role for this interface as a target for T6SS inhibition. Based on the high-resolution structure of the TssKFGE wedge complex, we rationally designed a biomimetic cyclic peptide (BCP) that blocks the assembly of the EAEC BP complex and inhibits the function of T6SS in bacterial cultures. Our BCP is the first compound completely designed from prior structural knowledge with anti-T6SS activity that can be used as a model to target human pathogens.
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50
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Peterson SB, Bertolli SK, Mougous JD. The Central Role of Interbacterial Antagonism in Bacterial Life. Curr Biol 2021; 30:R1203-R1214. [PMID: 33022265 DOI: 10.1016/j.cub.2020.06.103] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The study of bacteria interacting with their environment has historically centered on strategies for obtaining nutrients and resisting abiotic stresses. We argue this focus has deemphasized a third facet of bacterial life that is equally central to their existence: namely, the threat to survival posed by antagonizing bacteria. The diversity and ubiquity of interbacterial antagonism pathways is becoming increasingly apparent, and the insidious manner by which interbacterial toxins disarm their targets emphasizes the highly evolved nature of these processes. Studies examining the role of antagonism in natural communities reveal it can serve many functions, from facilitating colonization of naïve habitats to maintaining bacterial community stability. The pervasiveness of antagonistic pathways is necessarily matched by an equally extensive array of defense strategies. These overlap with well characterized, central stress response pathways, highlighting the contribution of bacterial interactions to shaping cell physiology. In this review, we build the case for the ubiquity and importance of interbacterial antagonism.
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Affiliation(s)
- S Brook Peterson
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Savannah K Bertolli
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | - Joseph D Mougous
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA.
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