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Brinch C, Otani S, Munk P, van den Beld M, Franz E, Aarestrup FM. Discovery of Vibrio cholerae in Urban Sewage in Copenhagen, Denmark. MICROBIAL ECOLOGY 2024; 87:102. [PMID: 39085652 PMCID: PMC11291605 DOI: 10.1007/s00248-024-02419-7] [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: 06/13/2024] [Accepted: 07/23/2024] [Indexed: 08/02/2024]
Abstract
We report the discovery of a persistent presence of Vibrio cholerae at very low abundance in the inlet of a single wastewater treatment plant in Copenhagen, Denmark at least since 2015. Remarkably, no environmental or locally transmitted clinical case of V. cholerae has been reported in Denmark for more than 100 years. We, however, have recovered a near-complete genome out of 115 metagenomic sewage samples taken over the past 8 years, despite the extremely low relative abundance of one V. cholerae read out of 500,000 sequenced reads. Due to the very low relative abundance, routine screening of the individual samples did not reveal V. cholerae. The recovered genome lacks the gene responsible for cholerae toxin production, but although this strain may not pose an immediate public health risk, our finding illustrates the importance, challenges, and effectiveness of wastewater-based pathogen surveillance.
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Affiliation(s)
- Christian Brinch
- Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark.
| | - Saria Otani
- Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
| | - Patrick Munk
- Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
| | - Maaike van den Beld
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Eelco Franz
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Frank M Aarestrup
- Research Group for Genomic Epidemiology, Technical University of Denmark, Kgs, Lyngby, Denmark
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Otto SB, Servajean R, Lemopoulos A, Bitbol AF, Blokesch M. Interactions between pili affect the outcome of bacterial competition driven by the type VI secretion system. Curr Biol 2024; 34:2403-2417.e9. [PMID: 38749426 DOI: 10.1016/j.cub.2024.04.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 04/09/2024] [Accepted: 04/22/2024] [Indexed: 06/06/2024]
Abstract
The bacterial type VI secretion system (T6SS) is a widespread, kin-discriminatory weapon capable of shaping microbial communities. Due to the system's dependency on contact, cellular interactions can lead to either competition or kin protection. Cell-to-cell contact is often accomplished via surface-exposed type IV pili (T4Ps). In Vibrio cholerae, these T4Ps facilitate specific interactions when the bacteria colonize natural chitinous surfaces. However, it has remained unclear whether and, if so, how these interactions affect the bacterium's T6SS-mediated killing. In this study, we demonstrate that pilus-mediated interactions can be harnessed by T6SS-equipped V. cholerae to kill non-kin cells under liquid growth conditions. We also show that the naturally occurring diversity of pili determines the likelihood of cell-to-cell contact and, consequently, the extent of T6SS-mediated competition. To determine the factors that enable or hinder the T6SS's targeted reduction of competitors carrying pili, we developed a physics-grounded computational model for autoaggregation. Collectively, our research demonstrates that T4Ps involved in cell-to-cell contact can impose a selective burden when V. cholerae encounters non-kin cells that possess an active T6SS. Additionally, our study underscores the significance of T4P diversity in protecting closely related individuals from T6SS attacks through autoaggregation and spatial segregation.
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Affiliation(s)
- Simon B Otto
- Laboratory of Molecular Microbiology, Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Richard Servajean
- Laboratory of Computational Biology and Theoretical Biophysics, Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Alexandre Lemopoulos
- Laboratory of Molecular Microbiology, Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Anne-Florence Bitbol
- Laboratory of Computational Biology and Theoretical Biophysics, Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Melanie Blokesch
- Laboratory of Molecular Microbiology, Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
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Bina XR, Bina JE. Vibrio cholerae RND efflux systems: mediators of stress responses, colonization and pathogenesis. Front Cell Infect Microbiol 2023; 13:1203487. [PMID: 37256112 PMCID: PMC10225521 DOI: 10.3389/fcimb.2023.1203487] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 04/25/2023] [Indexed: 06/01/2023] Open
Abstract
Resistance Nodulation Division (RND) efflux systems are ubiquitous transporters in gram-negative bacteria that provide protection against antimicrobial agents and thereby enhance survival in virtually all environments these prokaryotes inhabit. Vibrio cholerae is a dual lifestyle enteric pathogen that spends much of its existence in aquatic environments. An unwitting encounter with a human host can lead to V. cholerae intestinal colonization by strains that encode cholera toxin and toxin co-regulated pilus virulence factors leading to potentially fatal cholera diarrhea and dissemination in the environment. Adaptive response mechanisms to host factors encountered by these pathogens are therefore critical both to engage survival mechanisms such as RND-mediated transporters and to induce timely expression of virulence factors. Sensing of cues encountered in the host may therefore activate more than protective responses such as efflux systems, but also be coordinated to initiate expression of virulence factors. This review summarizes recent advances that contribute towards the understanding of RND efflux physiological functions and how the transport systems interface with the regulation of virulence factor production in V. cholerae.
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Affiliation(s)
| | - James E. Bina
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
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Luo Y, Wang H, Liang J, Qian H, Ye J, Chen L, Yang X, Chen Z, Wang F, Octavia S, Payne M, Song X, Jiang J, Jin D, Lan R. Population Structure and Multidrug Resistance of Non-O1/Non-O139 Vibrio cholerae in Freshwater Rivers in Zhejiang, China. MICROBIAL ECOLOGY 2021; 82:319-333. [PMID: 33410933 DOI: 10.1007/s00248-020-01645-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/15/2020] [Indexed: 06/12/2023]
Abstract
To understand the environmental reservoirs of Vibrio cholerae and their public health significance, we surveyed freshwater samples from rivers in two cities (Jiaxing [JX] and Jiande [JD]) in Zhejiang, China. A total of 26 sampling locations were selected, and river water was sampled 456 times from 2015 to 2016 yielding 200 V. cholerae isolates, all of which were non-O1/non-O139. The average isolation rate was 47.3% and 39.1% in JX and JD, respectively. Antibiotic resistance profiles of the V. cholerae isolates were examined with nonsusceptibility to cefazolin (68.70%, 79/115) being most common, followed by ampicillin (47.83%, 55/115) and imipenem (27.83%, 32/115). Forty-two isolates (36.52%, 42/115) were defined as multidrug resistant (MDR). The presence of virulence genes was also determined, and the majority of the isolates were positive for toxR (198/200, 99%) and hlyA (196/200, 98%) with few other virulence genes observed. The population structure of the V. cholerae non-O1/non-O139 sampled was examined using multilocus sequence typing (MLST) with 200 isolates assigned to 128 STs and 6 subpopulations. The non-O1/non-O139 V. cholerae population in JX was more varied than in JD. By clonal complexes (CCs), 31 CCs that contained isolates from this study were shared with other parts of China and/or other countries, suggesting widespread presence of some non-O1/non-O139 clones. Drug resistance profiles differed between subpopulations. The findings suggest that non-O1/non-O139 V. cholerae in the freshwater environment is a potential source of human infections. Routine surveillance of non-O1/non-O139 V. cholerae in freshwater rivers will be of importance to public health.
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Affiliation(s)
- Yun Luo
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310052, Zhejiang, China
| | - Henghui Wang
- Jiaxing Center for Disease Control and Prevention, Jiaxing, 314050, Zhejiang, China
| | - Jie Liang
- Jiande Center for Disease Control and Prevention, Hangzhou, 311600, Zhejiang, China
| | - Huiqin Qian
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310052, Zhejiang, China
| | - Julian Ye
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310052, Zhejiang, China
| | - Lixia Chen
- Jiaxing Center for Disease Control and Prevention, Jiaxing, 314050, Zhejiang, China
| | - Xianqing Yang
- Jiande Center for Disease Control and Prevention, Hangzhou, 311600, Zhejiang, China
| | - Zhongwen Chen
- Jiaxing Center for Disease Control and Prevention, Jiaxing, 314050, Zhejiang, China
| | - Fei Wang
- Jiande Center for Disease Control and Prevention, Hangzhou, 311600, Zhejiang, China
| | - Sophie Octavia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Michael Payne
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Xiaojun Song
- Centre of Laboratory Medicine, Zhejiang Provincial People Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, 310014, Zhejiang, China
| | - Jianmin Jiang
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310052, Zhejiang, China
| | - Dazhi Jin
- Centre of Laboratory Medicine, Zhejiang Provincial People Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, 310014, Zhejiang, China
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, 310058, Zhejiang, China
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
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Abstract
Vibrio cholerae is a Gram-negative bacterium that causes the enteric disease cholera. V. cholerae colonization of the human intestine is dependent on the expression of both virulence genes and environmental adaptation genes involved in antimicrobial resistance. The expression of virulence genes, including the genes encoding for the main virulence factors cholera toxin (CT) and the toxin coregulated pilus (TCP), are coordinately regulated by the ToxR regulon. Tripartite transport systems belonging to the ATP binding cassette, major facilitator, and Resistance-Nodulation-Division families are critical for V. cholerae pathogenesis. Transport systems belonging to these families contribute to myriad phenotypes including protein secretion, antimicrobial resistance and virulence. TolC plays a central role in bacterial physiology by functioning as the outer membrane pore protein for tripartite transport systems. Consistent with this, V. cholerae tolC was previously found to be required for MARTX toxin secretion and antimicrobial resistance. Herein we investigated the contribution of TolC to V. cholerae virulence. We documented that tolC was required for CT and TCP production in O1 El Tor V. cholerae. This phenotype was linked to repression of the critical ToxR regulon transcription factor aphA. Decreased aphA transcription correlated with increased expression of the LysR-family transcription factor leuO. Deletion of leuO restored aphA expression, and CT and TCP production, in a tolC mutant. The collective results document that tolC is required for ToxR regulon expression and further suggest that tolC may participate in a efflux-dependent feedback circuit to regulate virulence gene expression.
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ToxR Mediates the Antivirulence Activity of Phenyl-Arginine-β-Naphthylamide To Attenuate Vibrio cholerae Virulence. Infect Immun 2021; 89:e0014721. [PMID: 33941578 DOI: 10.1128/iai.00147-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Multidrug efflux systems belonging to the resistance-nodulation-cell division (RND) family are ubiquitous in Gram-negative bacteria and are critical for antimicrobial resistance. This realization has led to efforts to develop efflux pump inhibitors (EPI) for use as adjuvants for antibiotic treatment of resistant organisms. However, the functions of RND transporters extend beyond antimicrobial resistance to include physiological functions that are critical for pathogenesis, suggesting that EPIs could also be used as antivirulence therapeutics. This was documented in the enteric pathogen Vibrio cholerae, in which EPIs were shown to attenuate the production of the critical virulence factors cholera toxin (CT) and the toxin-coregulated pilus (TCP). In this study, we investigated the antivirulence mechanism of action of the EPI phenyl-arginine-β-naphthylamide (PAβN) on V. cholerae. Using bioassays, we documented that PAβN inhibited virulence factor production in three epidemic V. cholerae isolates. Transcriptional reporter studies and mutant analysis indicated that PAβN initiated a ToxR-dependent regulatory circuit to activate leuO expression and that LeuO repressed the expression of the critical virulence activator aphA to attenuate CT and TCP production. The antivirulence activity of PAβN was found to be dependent on the ToxR periplasmic sensing domain (PPD), suggesting that a feedback mechanism was involved in its activity. Collectively, the data indicated that PAβN inhibited V. cholerae virulence factor production by activating a ToxR-dependent metabolic feedback mechanism to repress the expression of the ToxR virulence regulon. This suggests that efflux pump inhibitors could be used as antivirulence therapeutics for the treatment of cholera and perhaps that of other Gram-negative pathogens.
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Daboul J, Weghorst L, DeAngelis C, Plecha SC, Saul-McBeth J, Matson JS. Characterization of Vibrio cholerae isolates from freshwater sources in northwest Ohio. PLoS One 2020; 15:e0238438. [PMID: 32881972 PMCID: PMC7470319 DOI: 10.1371/journal.pone.0238438] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/17/2020] [Indexed: 01/22/2023] Open
Abstract
Vibrio cholerae is a natural inhabitant of aquatic ecosystems worldwide, typically residing in coastal or brackish water. While more than 200 serogroups have been identified, only serogroups O1 and O139 have been associated with epidemic cholera. However, infections other than cholera can be caused by nonepidemic, non-O1/non-O139 V. cholerae strains, including gastroenteritis and extraintestinal infections. While V. cholerae can also survive in freshwater, that is typically only observed in regions of the world where cholera is endemic. We recently isolated V. cholerae from several locations in lakes and rivers in northwest Ohio. These isolates were all found to be non-O1/non-O139 V. cholerae strains, that would not cause cholera. However, these isolates contained a variety of virulence genes, including ctxA, rtxA, rtxC, hlyA, and ompU. Therefore, it is possible that some of these isolates have the potential to cause gastroenteritis or other infections in humans. We also investigated the relative motility of the isolates and their ability to form biofilms as this is important for V. cholerae survival in the environment. We identified one isolate that forms very robust biofilms, up to 4x that of our laboratory strains. Finally, we investigated the susceptibility of these isolates to a panel of antibiotics. We found that many of the isolates showed decreased susceptibility to some of the antibiotics tested, which could be of concern. While we do not know if these isolates are pathogenic to humans, increased surveillance to better understand the public health risk to the local community should be considered.
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Affiliation(s)
- Judy Daboul
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, United States of America
| | - Logan Weghorst
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, United States of America
| | - Cara DeAngelis
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, United States of America
| | - Sarah C. Plecha
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, United States of America
| | - Jessica Saul-McBeth
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, United States of America
| | - Jyl S. Matson
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, United States of America
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