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Takahashi E, Kitahara K, Miyoshi SI, Chowdhury G, Mukhopadhyay AK, Dutta S, Ochi S, Okamoto K. Environmental water in Kolkata is suitable for the survival of Vibrio cholerae O1. ENVIRONMENTAL RESEARCH 2023; 222:115374. [PMID: 36709867 DOI: 10.1016/j.envres.2023.115374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/16/2022] [Accepted: 01/25/2023] [Indexed: 06/18/2023]
Abstract
Many patients with cholera emerge in Kolkata, India throughout the year. Such emergency indicates that cholera toxin-producing Vibrio cholerae O1 (toxigenic V. cholerae O1) are widespread in Kolkata. This suggests that the suitable conditions for replication of toxigenic V. cholerae O1 is provided in Kolkata. In previous studies, we found that the replication rate of toxigenic V. cholerae O1 is low in the low ionic aqueous solution. Then we measured the ion concentration in the environmental water of Kolkata. As a control, we measured them in Japanese environmental water. The ion concentration in the environmental water of Kolkata was significantly high. Then, we examined the survival of toxigenic V. cholerae O1 in groundwater from Kolkata and found that V. cholerae O1 survive for long time in the solution but not in the solution diluted with Milli Q water. In addition, we found that V. cholerae O1 proliferated in environmental water of Kolkata to which a small amount of nutrient was added, but did not grow in the environmental water diluted with water to which the same amount of nutrient was added. These results indicate that the environmental water from Kolkata is suitable for survival of V. cholerae O1.
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Affiliation(s)
- Eizo Takahashi
- Collaborative Research Center of Okayama University for Infectious Diseases in India, NICED-JICA Building, 57 Dr. S.C. Banerjee Road, Beliaghata, Kolkata, 700 010, India; Department of Health Pharmacy, Yokohama University of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama, Kanagawa, 245-0066, Japan
| | - Kei Kitahara
- Collaborative Research Center of Okayama University for Infectious Diseases in India, NICED-JICA Building, 57 Dr. S.C. Banerjee Road, Beliaghata, Kolkata, 700 010, India
| | - Shin-Ichi Miyoshi
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences of Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama, Okayama, 700-8530, Japan
| | - Goutam Chowdhury
- National Institute of Cholera and Enteric Diseases, NICED-JICA Building, 57 Dr. S.C. Banerjee Road, Beliaghata, Kolkata, 700 010, India
| | - Asish K Mukhopadhyay
- National Institute of Cholera and Enteric Diseases, NICED-JICA Building, 57 Dr. S.C. Banerjee Road, Beliaghata, Kolkata, 700 010, India
| | - Shanta Dutta
- National Institute of Cholera and Enteric Diseases, NICED-JICA Building, 57 Dr. S.C. Banerjee Road, Beliaghata, Kolkata, 700 010, India
| | - Sadayuki Ochi
- Department of Health Pharmacy, Yokohama University of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama, Kanagawa, 245-0066, Japan
| | - Keinosuke Okamoto
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences of Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama, Okayama, 700-8530, Japan.
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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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3
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Vibrio cholerae residing in food vacuoles expelled by protozoa are more infectious in vivo. Nat Microbiol 2019; 4:2466-2474. [PMID: 31570868 DOI: 10.1038/s41564-019-0563-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 07/19/2019] [Indexed: 11/09/2022]
Abstract
Vibrio cholerae interacts with many organisms in the environment, including heterotrophic protists (protozoa). Several species of protozoa have been reported to release undigested bacteria in expelled food vacuoles (EFVs) when feeding on some pathogens. While the production of EFVs has been reported, their biological role as a vector for the transmission of pathogens remains unknown. Here we report that ciliated protozoa release EFVs containing V. cholerae. The EFVs are stable, the cells inside them are protected from multiple stresses, and large numbers of cells escape when incubated at 37 °C or in the presence of nutrients. We show that OmpU, a major outer membrane protein positively regulated by ToxR, has a role in the production of EFVs. Notably, cells released from EFVs have growth and colonization advantages over planktonic cells both in vitro and in vivo. Our results suggest that EFVs facilitate V. cholerae survival in the environment, enhancing their infectious potential and may contribute to the dissemination of epidemic V. cholerae strains. These results improve our understanding of the mechanisms of persistence and the modes of transmission of V. cholerae and may further apply to other opportunistic pathogens that have been shown to be released by protists in EFVs.
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Perepelov AV, Li X, Xu C, Filatov AV, Shashkov AS, Senchenkova SN, Liu B. Structure elucidation and gene cluster characterization of the O-antigen of Vibrio cholerae O14. Carbohydr Res 2019; 474:67-71. [DOI: 10.1016/j.carres.2019.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 12/31/2018] [Accepted: 01/14/2019] [Indexed: 10/27/2022]
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5
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Noorian P, Hu J, Chen Z, Kjelleberg S, Wilkins MR, Sun S, McDougald D. Pyomelanin produced by Vibrio cholerae confers resistance to predation by Acanthamoeba castellanii. FEMS Microbiol Ecol 2018; 93:4582896. [PMID: 29095994 PMCID: PMC5812506 DOI: 10.1093/femsec/fix147] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 10/30/2017] [Indexed: 12/31/2022] Open
Abstract
Protozoan predation is one of the main environmental factors constraining bacterial growth in aquatic environments, and thus has led to the evolution of a number of defence mechanisms that protect bacteria from predation. These mechanisms may also function as virulence factors in infection of animal and human hosts. Whole transcriptome shotgun sequencing of Vibrio cholerae biofilms during predation by the amoebae, Acanthamoeba castellanii, revealed that 131 transcripts were significantly differentially regulated when compared to the non-grazed control. Differentially regulated transcripts included those involved in biosynthetic and metabolic pathways. The transcripts of genes involved in tyrosine metabolism were down-regulated in the grazed population, which indicates that the tyrosine metabolic regulon may have a role in the response of V. cholerae biofilms to A. castellanii predation. Homogentisate 1, 2-dioxygenase (HGA) is the main intermediate of the normal L-tyrosine catabolic pathway which is known to auto-oxidize, leading to the formation of the pigment, pyomelanin. Indeed, a pigmented mutant, disrupted in hmgA, was more resistant to amoebae predation than the wild type. Increased grazing resistance was correlated with increased production of pyomelanin and thus reactive oxygen species (ROS), suggesting that ROS production is a defensive mechanism used by bacterial biofilms against predation by amoebae A. castellanii.
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Affiliation(s)
- Parisa Noorian
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.,The ithree Institute, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Jie Hu
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Zhiliang Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.,Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Staffan Kjelleberg
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore
| | - Marc R Wilkins
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.,Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Shuyang Sun
- The ithree Institute, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Diane McDougald
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.,The ithree Institute, University of Technology Sydney, Sydney, NSW 2007, Australia.,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore
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6
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Batabyal P, Einsporn MH, Mookerjee S, Palit A, Neogi SB, Nair GB, Lara RJ. Influence of hydrologic and anthropogenic factors on the abundance variability of enteropathogens in the Ganges estuary, a cholera endemic region. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 472:154-161. [PMID: 24291141 DOI: 10.1016/j.scitotenv.2013.10.093] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Revised: 10/17/2013] [Accepted: 10/26/2013] [Indexed: 06/02/2023]
Abstract
This study deals with the influence of water physico-chemical properties, tides, rainfall and fecal pollution on the abundance of enteropathogens in a main distributary of the Ganges, in the endemic cholera belt of West Bengal. Between January and June 2011, water and sediments were sampled from two sites of the Hooghly River by Kolkata and Diamond Harbour. Counts of cultivable Vibrio (CVC, from~10(2) to~10(5)CFU/L) and total bacteria (TBC, from~10(5) to~10(9)CFU/L) increased with water temperature (17°C to 37°C). A combination of variations in tidal height, salinity and turbidity had a distinct influence on CVC, TBC and coliform counts. At Diamond Harbour, a salinity increase from 0.6 to 7.9 was accompanied by a 1000-fold amplification of initial CVC~10(2)CFU/L, whereas higher prevalence of coliforms in Kolkata was related to greater disposal of untreated sewage into the river. Turbidity-dependent variation of CVC was noteworthy, particularly at Diamond Harbour, where CVC in intertidal surface sediments showed an analogous trend as in surface waters, suggesting bentho-pelagic coupling of Vibrio dynamics. Besides the influence of salinity variation with tidal cycles, sediment re-suspension from tidal flats can play a role on Vibrio abundance in aquatic ecosystems.
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Affiliation(s)
- Prasenjit Batabyal
- National Institute of Cholera Enteric Diseases (ICMR), 700010 Kolkata, India
| | - Marc H Einsporn
- Leibniz Center for Marine Tropical Ecology (ZMT), 28359 Bremen, Germany.
| | - Subham Mookerjee
- National Institute of Cholera Enteric Diseases (ICMR), 700010 Kolkata, India
| | - Anup Palit
- National Institute of Cholera Enteric Diseases (ICMR), 700010 Kolkata, India
| | - Sucharit B Neogi
- International Centre for Diarrheal Disease Research, Bangladesh (ICDDR,B), Mohakhali, Dhaka 1212, Bangladesh; Graduate School of Life & Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Gopinath B Nair
- National Institute of Cholera Enteric Diseases (ICMR), 700010 Kolkata, India; Translational Health Science and Technology Institute, Udyog Vihar, Gurgaon-122016, Haryana, India
| | - Rubén J Lara
- Leibniz Center for Marine Tropical Ecology (ZMT), 28359 Bremen, Germany; Instituto Argentino de Oceanografía, 8000 Bahía Blanca, Argentina
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7
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Verma YK, Verma MK. CT gene modulate differential expression of chitinase gene under variant habitats in Vibrio cholerae. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2013. [DOI: 10.1016/s2222-1808(13)60005-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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Das M, Bhowmick TS, Nandy RK, Nair GB, Sarkar BL. Surveillance of vibriophages reveals their role as biomonitoring agents in Kolkata. FEMS Microbiol Ecol 2009; 67:502-10. [DOI: 10.1111/j.1574-6941.2008.00634.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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9
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Miller MC, Keymer DP, Avelar A, Boehm AB, Schoolnik GK. Detection and transformation of genome segments that differ within a coastal population of Vibrio cholerae strains. Appl Environ Microbiol 2007; 73:3695-704. [PMID: 17449699 PMCID: PMC1932674 DOI: 10.1128/aem.02735-06] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio cholerae is an autochthonous member of diverse aquatic ecosystems around the globe. Collectively, the genomes of environmental V. cholerae strains comprise a large repository of encoded functions which can be acquired by individual V. cholerae lineages through uptake and recombination. To characterize the genomic diversity of environmental V. cholerae, we used comparative genome hybridization to study 41 environmental strains isolated from diverse habitats along the central California coast, a region free of endemic cholera. These data were used to classify genes of the epidemic V. cholerae O1 sequenced strain N16961 as conserved, variably present, or absent from the isolates. For the most part, absent genes were restricted to large mobile elements and have known functions in pathogenesis. Conversely, genes present in some, but not all, California isolates were in smaller contiguous clusters and were less likely to be near genes with functions in DNA mobility. Two such clusters of variable genes encoding different selectable metabolic phenotypes (mannose and diglucosamine utilization) were transformed into the genomes of environmental isolates by chitin-dependent competence, indicating that this mechanism of general genetic exchange is conserved among V. cholerae. The transformed DNA had an average size of 22.7 kbp, demonstrating that natural competence can mediate the movement of large chromosome fragments. Thus, whether variable genes arise through the acquisition of new sequences by horizontal gene transfer or by the loss of preexisting DNA though deletion, natural transformation provides a mechanism by which V. cholerae clones can gain access to the V. cholerae pan-genome.
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Affiliation(s)
- Michael C Miller
- Department of Medicine, Stanford University School of Medicine, CA 94305, USA.
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10
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Maiti D, Das B, Saha A, Nandy RK, Nair GB, Bhadra RK. Genetic organization of pre-CTX and CTX prophages in the genome of an environmental Vibrio cholerae non-O1, non-O139 strain. Microbiology (Reading) 2006; 152:3633-3641. [PMID: 17159216 DOI: 10.1099/mic.0.2006/000117-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The cholera toxin (CT) is a critical determinant of the virulence of epidemic Vibrio cholerae strains. The ctxAB operon encoding CT is part of the genome of a filamentous bacteriophage CTXΦ, which may integrate as a single copy or as multiple copies in the genome of V. cholerae. The CTXΦ genome is composed of RS2 (2.4 kb) and core (4.5 kb) regions. In the present study extensive genetic mapping analyses indicated that two copies of tandemly arrayed CTX prophages are integrated in the small chromosome of an environmental V. cholerae strain, VCE232, belonging to serogroup O4. Further mapping revealed that the integration of prophages has occurred in the same genetic locus of the small chromosome of VCE232 as that of V. cholerae O1 biotype El Tor strains. Interestingly, a new type of RS2-like element 3.5 kb in size was found in the CTX prophage genome in the small chromosome of VCE232. Cloning followed by sequencing of the new RS2-like element of VCE232 revealed the presence of three ORFs, which probably encode highly divergent types of phage regulatory proteins. Furthermore, the strain VCE232 also harbours two copies of a tandemly arranged CTX prophage devoid of the ctxAB genes, called pre-CTX prophage, in its large chromosome. The presence of multiple copies of diverse CTX prophages in both the chromosomes of VCE232 suggests that toxigenic environmental V. cholerae non-O1, non-O139 strains could play a role in the emergence of new epidemic clones.
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Affiliation(s)
- Diganta Maiti
- Infectious Diseases Group, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Bhabatosh Das
- Infectious Diseases Group, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Arjun Saha
- Infectious Diseases Group, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, India
| | - Ranjan K Nandy
- National Institute of Cholera and Enteric Diseases, Beliaghata, Kolkata 700 010, India
| | - G Balakrish Nair
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka 1212, Bangladesh
| | - Rupak K Bhadra
- Infectious Diseases Group, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata 700 032, India
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Bhattacharya T, Chatterjee S, Maiti D, Bhadra RK, Takeda Y, Nair GB, Nandy RK. Molecular analysis of the rstR and orfU genes of the CTX prophages integrated in the small chromosomes of environmental Vibrio cholerae non-O1, non-O139 strains. Environ Microbiol 2006; 8:526-634. [PMID: 16478458 DOI: 10.1111/j.1462-2920.2005.00932.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ctxAB genes encoding cholera toxin, reside in the genome of a filamentous bacteriophage CTXphi. The presence of CTX prophage in non-epidemic environmental Vibrio cholerae strains is rare. The CTX prophage, the lysogenic form of CTXphi in V. cholerae, is comprised of the 'RS2' and the 'Core'. Analysis of the rstR gene present in the RS2 region of the CTX prophage revealed the presence of new alleles of the prophages in four environmental non-O1, non-O139 strains VCE22 (O36), VCE228 (O27), VCE232 (O4) and VCE233 (O27), and the CTX prophages are located in the small chromosomes. Phylogenetic analysis based on the nucleotide sequences of the rstR and orfU (present in the core) genes of these prophages placed them in a single unique cluster, which is distally located compared with that of epidemic V. cholerae O1 strains. Further analysis indicated that the genome of the prophage present in the strain VCE22 is devoid of the ctxAB genes, called pre-CTX prophage and the strain also possess the toxin-coregulated pilus protein coding gene tcpA of classical type, another important pathogenicity determining locus of the epidemic V. cholerae strains. Comparative analysis of the nucleotide sequences of the rstR and orfU genes indicated that the pre-CTX prophage of VCE22 might be the progenitor of new alleles of the CTX prophages present in these environmental strains.
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Affiliation(s)
- Tanuja Bhattacharya
- National Institute of Cholera and Enteric Diseases, P-33, CIT Road Scheme XM, Beliaghata, Kolkata 700010, India
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O'Shea YA, Reen FJ, Quirke AM, Boyd EF. Evolutionary genetic analysis of the emergence of epidemic Vibrio cholerae isolates on the basis of comparative nucleotide sequence analysis and multilocus virulence gene profiles. J Clin Microbiol 2004; 42:4657-71. [PMID: 15472325 PMCID: PMC522369 DOI: 10.1128/jcm.42.10.4657-4671.2004] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio cholerae, the causative agent of cholera, is a natural inhabitant of the aquatic ecosystem. We examined a unique collection of V. cholerae clinical and environmental isolates of widespread geographic distribution recovered over a 60-year period to determine their evolutionary genetic relationships based on analysis of two housekeeping genes, malate dehydrogenase (mdh) and a chaperonin (groEL). In addition, the phylogenetic distribution of 12 regions associated with virulence was determined. Comparative sequence analysis of mdh revealed that all V. cholerae O1 and O139 serogroup isolates belonged to the same clonal lineage. Single-strand conformational polymorphism (SSCP) analysis of these O1 and O139 strains at groEL confirmed the presence of an epidemic clonal complex. Of the 12 virulence regions examined, only three regions, Vibrio seventh pandemic island 1 (VSP-I), VSP-II, and RS1, were absent from all classical V. cholerae isolates. Most V. cholerae El Tor biotype and O139 serogroup isolates examined encoded all 12 virulence regions assayed. Outside of V. cholerae O1/O139 serogroup isolates, only one strain, VO7, contained VSP-I. Two V. cholerae El Tor isolates, GP155 and 2164-78, lacked both VSP-I and VSP-II, and one El Tor isolate, GP43, lacked VSP-II. Five non-O1/non-O139 serogroup isolates had an mdh sequence identical to that of the epidemic O1 and O139 strains. These isolates, similar to classical strains, lack both VSP-I and VSP-II. Four of the 12 virulence regions examined were found to be present in all isolates: hlyA, pilE, MSHA and RTX. Among non-O1/non-O139 isolates, however, the occurrence of the additional eight regions was considerably lower. The evolutionary relationships and multilocus virulence gene profiles of V. cholerae natural isolates indicate that consecutive pandemic strains arose from a common O1 serogroup progenitor through the successive acquisition of new virulence regions.
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Affiliation(s)
- Yvonne A O'Shea
- Department of Microbiology, University College Cork, National University of Ireland, Cork, Ireland
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13
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Abstract
When exponentially growing Vibrio cholerae cells were shifted from 37 degrees C to various lower temperatures, it was found that the organism could adapt and grow at temperatures down to 15 degrees C, below which the growth was completely arrested. There was no difference between the patterns of the cold shock responses in toxinogenic and nontoxinogenic strains of V. cholerae. Gel electrophoretic analyses of proteins of cold-exposed cells revealed significant induction of two major cold shock proteins (Csps), whose molecular masses were 7.7 kDa (CspA(VC)) and 7.5 kDa (CspV), and six other Csps, most of which were much larger. We cloned, sequenced, and analyzed the cspV gene encoding the CspV protein of V. cholerae O139 strain SG24. Although CspA(VC) and CspV have similar kinetics of synthesis and down-regulation, the corresponding genes, cspA and cspV, which are located in the small chromosome, are not located in the same operon. A comparative analysis of the kinetics of synthesis revealed that the CspV protein was synthesized de novo only during cold shock. Although both CspA(VC) and CspV were stable for several hours in the cold, the CspV protein was degraded rapidly when the culture was shifted back to 37 degrees C, suggesting that this protein is probably necessary for adaptation at lower temperatures. Northern blot analysis confirmed that the cspV gene is cold shock inducible and is regulated tightly at the level of transcription. Interestingly, the cspV gene has a cold shock-inducible promoter which is only 12 nucleotides from the translational start site, and therefore, it appears that no unusually long 5' untranslated region is present in its mRNA transcript. Thus, this promoter is an exception compared to other promoters of cold shock-inducible genes of different organisms, including Escherichia coli. Our results suggest that V. cholerae may use an alternative pathway for regulation of gene expression during cold shock.
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Affiliation(s)
- Partha Pratim Datta
- Infectious Diseases Division, Indian Institute of Chemical Biology, Calcutta 700032, India
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Islam MS, Kabir MS, Khan SI, Ekramullah M, Nair GB, Sack RB, Sack DA. Wastewater-grown duckweed may be safely used as fish feed. Can J Microbiol 2004; 50:51-6. [PMID: 15052321 DOI: 10.1139/w03-102] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Duckweed has been used for the treatment of wastewater and as fish feed. A comparative study was carried out to determine (i) the efficacy of duckweed in treating hospital-based wastewater and (ii) the level of the microbial contamination of fish fed on wastewater-grown duckweed. There were two groups of ponds where fish farming was done. In one group of ponds (control ponds), duckweed that was grown using artificial fertilizer was used as fish feed; in another group (study ponds), wastewater-grown duckweed was used as fish feed. The faecal contamination of water, duckweed, and fish from study and control ponds were monitored by faecal coliform estimation. The presence of enteric pathogens among handlers, water, duckweed, and fish samples was also examined. It was observed that the faecal coliform counts of raw wastewater were 4.7 Log10CFU/mL, which was reduced to <1 Log10CFU/mL after treating with duckweed. There was no significant difference (P > 0.05) in faecal coliform counts in water collected from duckweed ponds and fish ponds of study and control areas. The wastewater-grown duckweed did not pose any health hazard to the handlers. These results demonstrated that the wastewater-treated duckweed may be safely used as fish feed.Key words: wastewater, duckweed, fish feed, contamination, safety.
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Affiliation(s)
- M S Islam
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka.
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Zo YG, Rivera ING, Russek-Cohen E, Islam MS, Siddique AK, Yunus M, Sack RB, Huq A, Colwell RR. Genomic profiles of clinical and environmental isolates of Vibrio cholerae O1 in cholera-endemic areas of Bangladesh. Proc Natl Acad Sci U S A 2002; 99:12409-14. [PMID: 12205294 PMCID: PMC129458 DOI: 10.1073/pnas.192426499] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Diversity, relatedness, and ecological interactions of toxigenic Vibrio cholerae O1 populations in two distinctive habitats, the human intestine and the aquatic environment, were analyzed. Twenty environmental isolates and 42 clinical isolates were selected for study by matching serotype, geographic location of isolation in Bangladesh, and season of isolation. Genetic profiling was done by enterobacterial repetitive intergenic consensus sequence-PCR, optimized for profiling by using the fully sequenced V. cholerae El Tor N16961 genome. Five significant clonal clusters of haplotypes were found from 57 electrophoretic types. Isolates from different areas or habitats intermingled in two of the five significant clusters. Frequencies of haplotypes differed significantly only between the environmental populations (exact test; P < 0.05). Analysis of molecular variance yielded a population genetic structure reflecting the differentiating effects of geographic area, habitat, and sampling time. Although a parameter confounding the latter differences explained 9% of the total molecular variance in the entire population (P < 0.01), the net effect of habitat and time could not be separated because of the small number of environmental isolates included in the study. Five subpopulations from a single area were determined, and from these we were able to estimate a relative differentiating effect of habitat, which was small compared with the effect of temporal change. In conclusion, the resulting population structure supports the hypothesis that spatial and temporal fluctuations in the composition of toxigenic V. cholerae populations in the aquatic environment can cause shifts in the dynamics of the disease.
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Affiliation(s)
- Young-Gun Zo
- Center of Marine Biotechnology, University of Maryland Biotechnology Institute, Baltimore, MD 21202, USA
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16
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Mukhopadhyay AK, Chakraborty S, Takeda Y, Nair GB, Berg DE. Characterization of VPI pathogenicity island and CTXphi prophage in environmental strains of Vibrio cholerae. J Bacteriol 2001; 183:4737-46. [PMID: 11466276 PMCID: PMC99527 DOI: 10.1128/jb.183.16.4737-4746.2001] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Environmental isolates of Vibrio cholerae of eight randomly amplified polymorphic DNA (RAPD) fingerprint types from Calcutta, India, that were unusual in containing toxin-coregulated pilus or cholera toxin genes but not O1 or O139 antigens of epidemic strains were studied by PCR and sequencing to gain insights into V. cholerae evolution. We found that each isolate contained a variant form of the VPI pathogenicity island. Distinguishing features included (i) four new alleles of tcpF (which encodes secreted virulence protein; its exact function is unknown), 20 to 70% divergent (at the protein level) from each other and canonical tcpF; (ii) a new allele of toxT (virulence regulatory gene), 36% divergent (at the protein level) in its 5' half and nearly identical in its 3' half to canonical toxT; (iii) a new tcpA (pilin) gene; and (iv) four variant forms of a regulatory sequence upstream of toxT. Also found were transpositions of an IS903-related element and function-unknown genes to sites in VPI. Cholera toxin (ctx) genes were found in isolates of two RAPD types, in each case embedded in CTXphi-like prophages. Fragments that are inferred to contain only putative repressor, replication, and integration genes were present in two other RAPD types. New possible prophage repressor and replication genes were also identified. Our results show marked genetic diversity in the virulence-associated gene clusters found in some nonepidemic V. cholerae strains, suggest that some of these genes contribute to fitness in nature, and emphasize the potential importance of interstrain gene exchange in the evolution of this species.
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Affiliation(s)
- A K Mukhopadhyay
- Departments of Molecular Microbiology and Genetics, Washington University Medical School, St. Louis, Missouri 63110, USA
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17
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Chakraborty S, Mukhopadhyay AK, Bhadra RK, Ghosh AN, Mitra R, Shimada T, Yamasaki S, Faruque SM, Takeda Y, Colwell RR, Nair GB. Virulence genes in environmental strains of Vibrio cholerae. Appl Environ Microbiol 2000; 66:4022-8. [PMID: 10966424 PMCID: PMC92254 DOI: 10.1128/aem.66.9.4022-4028.2000] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The virulence of a pathogen is dependent on a discrete set of genetic determinants and their well-regulated expression. The ctxAB and tcpA genes are known to play a cardinal role in maintaining virulence in Vibrio cholerae, and these genes are believed to be exclusively associated with clinical strains of O1 and O139 serogroups. In this study, we examined the presence of five virulence genes, including ctxAB and tcpA, as well as toxR and toxT, which are involved in the regulation of virulence, in environmental strains of V. cholerae cultured from three different freshwater lakes and ponds in the eastern part of Calcutta, India. PCR analysis revealed the presence of these virulence genes or their homologues among diverse serotypes and ribotypes of environmental V. cholerae strains. Sequencing of a part of the tcpA gene carried by an environmental strain showed 97.7% homology to the tcpA gene of the classical biotype of V. cholerae O1. Strains carrying the tcpA gene expressed the toxin-coregulated pilus (TCP), demonstrated by both autoagglutination analysis and electron microscopy of the TCP pili. Strains carrying ctxAB genes also produced cholera toxin, determined by monosialoganglioside enzyme-linked immunosorbent assay and by passage in the ileal loops of rabbits. Thus, this study demonstrates the presence and expression of critical virulence genes or their homologues in diverse environmental strains of V. cholerae, which appear to constitute an environmental reservoir of virulence genes, thereby providing new insights into the ecology of V. cholerae.
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Affiliation(s)
- S Chakraborty
- National Institute of Cholera and Enteric Diseases, Beliaghata, Calcutta 700 010, India
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18
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Mitra R, Saha PK, Basu I, Venkataraman A, Ramakrishna BS, Albert MJ, Takeda Y, Nair GB. Characterization of non-membrane-damaging cytotoxin of non-toxigenic Vibrio cholerae O1 and its relevance to disease. FEMS Microbiol Lett 1998; 169:331-9. [PMID: 9868778 DOI: 10.1111/j.1574-6968.1998.tb13337.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The non-membrane-damaging cytotoxin which causes dramatic cell rounding of cultured HeLa cells was purified to homogeneity from a clinical strain (WO5) of non-toxigenic Vibrio cholerae O1 Inaba belonging to the E1 Tor biotype. The purified protein has a denatured molecular weight of 35 kDa and a native molecular weight of approximately 37 kDa indicating the monomeric nature of the protein. The 15 N-terminal amino acid sequence of non-membrane-damaging cytotoxin showed complete homology to the hemagglutinin protease previously purified and characterized from V. cholerae O1. Purified non-membrane-damaging cytotoxin from V. cholerae O1 was immunologically and biochemically identical to that previously purified from V. cholerae O26. Non-membrane-damaging cytotoxin was found to be enterotoxic in rabbit ileal loop assay inducing accumulation of non-hemorrhagic fluid at 100 micrograms and elicited a concentration dependent increase in short circuit current and tissue conductance of rabbit ileal mucosa mounted on Ussing chambers. A significant serum immunoglobulin G response against non-membrane-damaging cytotoxin was elicited by patients infected with V. cholerae O139 but not with V. cholerae O1. These properties make non-membrane-damaging cytotoxin a potential virulence factor of V. cholerae which should be taken into consideration while making live, attenuated recombinant vaccine strains against cholera.
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Affiliation(s)
- R Mitra
- National Institute of Cholera and Enteric Diseases, Calcutta, India
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19
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Caldini G, Neri A, Cresti S, Boddi V, Rossolini GM, Lanciotti E. High Prevalence of Vibrio cholerae Non-O1 Carrying Heat-Stable-Enterotoxin-Encoding Genes among Vibrio Isolates from a Temperate-Climate River Basin of Central Italy. Appl Environ Microbiol 1997; 63:2934-9. [PMID: 16535661 PMCID: PMC1389216 DOI: 10.1128/aem.63.7.2934-2939.1997] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio spp. of clinical interest from the Arno River basin (Tuscany, Italy) were investigated in this study. Vibrios were isolated from 70% of water samples. Vibrio cholerae non-O1 was the most prevalent species (82% of isolates), followed by Vibrio mimicus (10%) and Vibrio metschnikovii (8%). Recovery of vibrios was correlated with temperature, pH, and various indicators of municipal pollution. None of the 150 Vibrio isolates carried ctx-related genomic sequences, whereas 18 (14.6%) of the 123 V. cholerae non-O1 isolates and 1 (6.7%) of the 15 V. mimicus isolates carried sto alleles. These findings indicate that considerable circulation of sto-positive vibrios may occur in temperate-climate freshwater environments.
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20
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Chakraborty S, Nair GB, Shinoda S. Pathogenic vibrios in the natural aquatic environment. REVIEWS ON ENVIRONMENTAL HEALTH 1997; 12:63-80. [PMID: 9273923 DOI: 10.1515/reveh.1997.12.2.63] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In recent years, members belonging to the genus Vibrio of the family Vibrionaceae have acquired increasing importance because of the association of several of its members with human disease. The most feared of the Vibrio species is Vibrio cholerae, the causative agent of cholera, a devastating disease of global significance. Other important vibrios of medical importance are V. parahemolyticus, V. vulnificus, V. mimicus, and to a lesser extent V. fluvialis, V. furnissii, V. hollisae, and V. damsela. Recent studies have also implicated V. alginolyticus and V. metschnikovii in human disease, although their complete significance has not yet been established. The virulence of all medically important vibrios is aided by a variety of traits that help breach human defenses. In this review, we provide an overview of the environmental distribution of the pathogenic vibrios and the important virulence traits that enable them to cause disease.
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Affiliation(s)
- S Chakraborty
- National Institute of Cholera & Enteric Diseases, Calcutta, India
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21
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Mezrioui N, Oufdou K. Abundance and antibiotic resistance of non-O1 Vibrio cholerae strains in domestic wastewater before and after treatment in stabilization ponds in an arid region (Marrakesh, Morocco). FEMS Microbiol Ecol 1996. [DOI: 10.1111/j.1574-6941.1996.tb00124.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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22
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McCarthy SA. Effects of temperature and salinity on survival of toxigenicVibrio cholerae O1 in seawater. MICROBIAL ECOLOGY 1996; 31:167-175. [PMID: 24185740 DOI: 10.1007/bf00167862] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/1995] [Revised: 05/03/1995] [Indexed: 06/02/2023]
Abstract
In 1991 and 1992, the Latin American epidemic strain of Vibrio cholerae O1 was isolated from ballast water, bilge water, and sewage taken from cargo ships docked in Mobile Bay, Alabama. The findings raised questions regarding the organism's ability to survive long-term aboard ships and to withstand the exchange of ballast at sea. The effects of temperature (6, 18, and 30°C) and salinity (8, 16, and 32 ppt) on survival of V. cholerae O1 strains C6706 and C6707 and a ballast water isolate in sterile seawater were determined. The ballast water isolate, which had a D-value (number of days required to produce a 1 log10 reduction in colony-forming units per milliliter) of 240 days at 18°C, 32 ppt salinity, had the longest survival time. The range of D-values was 36-240 days at 18°C, 60-120 days at 30°C, and 5-20 days at 6°C. In sterile seawater short-term survival was temperature dependent, whereas long-term survival was salinity dependent. In raw seawater, survival time of the ballast water isolate was reduced to 12-27 days, implying the existence of biological influences. As also shown in our previous work, the organism appeared to be able to survive for several months under relatively stable conditions in ballast water aboard ships; however, viability may be reduced to only a few weeks after the organism is introduced into estuarine or marine environments.
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Affiliation(s)
- S A McCarthy
- Gulf Coast Seafood Laboratory, U.S. Food and Drug Administration, P.O. Box 158, 36528, Dauphin Island, Alabama, USA
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23
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Abstract
A case of primary septicaemia with a Vibrio cholerae not agglutinable with O group 1 sera is reported in a burn patient. This appears to be the first reported case of this organism causing infection in a burn patient. The case is discussed, highlighting the difficulties encountered in treating this unexpected organism and the course of the infection in this patient. It is probable that the organism was obtained during first aid for the burn wound.
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24
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Mezrioui N, Oufdou K, Baleux B. Dynamics of non-O1 Vibrio cholerae and fecal coliforms in experimental stabilization ponds in the arid region of Marrakesh, Morocco, and the effect of pH, temperature, and sunlight on their experimental survival. Can J Microbiol 1995; 41:489-98. [PMID: 7627909 DOI: 10.1139/m95-065] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We studied the spatial-temporal dynamics of non-O1 Vibrio cholerae numbers at a stabilization pond treatment plant. This bacterium's seasonal dynamics were the inverse of those of fecal coliforms, with high levels in hot periods and low levels in cold periods. Stabilization pond treatment did not significantly reduce non-O1 V. cholerae numbers between the system's inflow and outflow points. In contrast, fecal coliforms were reduced by 98.95% in hot periods and by 94.91% in cold periods. Significant rho coefficient values for the Spearman correlation between numbers of non-O1 V. cholerae and temperature and pH of 0.91 and 0.76 respectively, were found at the system's outflow point. An experimental study of the effects of pH, temperature, and sunlight on the survival of non-O1 V. cholerae and fecal coliforms confirmed the inverse behaviour of the two bacterial groups noted in the stabilization ponds. Alkaline pH values of 8 and 8.8 promoted the survival of non-O1 V. cholerae and inhibited that of Escherichia coli. Low temperatures (8 degrees C) prolonged E. coli survival (k = 0.002/h), while a temperature of 23 degrees C reduced it markedly (k = 0.022/h). Non-O1 V. cholerae did not survive as well as E. coli at 8 degrees C (k = 0.009/h). The effect of temperature on non-O1 V. cholerae appeared to be closely linked to nutrient levels. Non-O1 V. cholerae appeared to be less sensitive to sunlight than E. coli whose survival was markedly reduced particularly during summer periods. Non-O1 V. cholerae and E. coli did not behave in the same way in water subjected to stabilization pond treatment. The use of fecal coliforms as an indicator of the potential health hazard of the effluent may not be adequate for this treatment procedure.
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Affiliation(s)
- N Mezrioui
- Laboratoire de microbiologie, Département de biologie, Université Cadi Ayyad, Marrakech, Morocco
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25
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Ghosh AR, Koley H, De D, Garg S, Bhattacharya M, Bhattacharya S, Manna B, Nair GB, Shimada T, Takeda T, Takeda Y. Incidence and toxigenicity of Vibrio cholerae in a freshwater lake during the epidemic of cholera caused by serogroup O139 Bengal in Calcutta, India. FEMS Microbiol Ecol 1994. [DOI: 10.1111/j.1574-6941.1994.tb00114.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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26
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27
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Chaudhuri K, Bhadra RK, Das J. Cell surface characteristics of environmental and clinical isolates of Vibrio cholerae non-O1. Appl Environ Microbiol 1992; 58:3567-73. [PMID: 1282793 PMCID: PMC183145 DOI: 10.1128/aem.58.11.3567-3573.1992] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The cell surfaces of several toxigenic and nontoxigenic environmental and clinical isolates of Vibrio cholerae non-O1 have been examined. The environmental strains, irrespective of toxigenicity, are significantly more resistant to antibiotics and detergents than are V. cholerae O1 strains. The clinical isolates of non-O1 vibrios are as sensitive to a wide variety of chemicals as the O1 vibrios. The environmental non-O1 strains are also less susceptible to lysis when treated with protein denaturants or neutral and anionic detergents than are O1 vibrios and the clinical non-O1 strains. In contrast to O1 vibrios, the environmental non-O1 vibrios do not have exposed phospholipids in their outer membranes. These features of the cell surfaces of environmental non-O1 vibrios might have a role in the better survival of these organisms under environmental fluctuations.
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Affiliation(s)
- K Chaudhuri
- Biophysics Division, Indian Institute of Chemical Biology, Jadavpur, Calcutta
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28
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Balakrish Nair G, Bhadra RK, Ramamurthy T, Ramesh A, Pal S. Vibrio cholerae and other vibrios associated with paddy field cultured prawns. Food Microbiol 1991. [DOI: 10.1016/0740-0020(91)90051-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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29
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Ghosh AR, Nair GB, Naik TN, Sarkar SK, Mazumdar R, Pal SC, Sen D. Serovars of multi-antibiotic resistant Escherichia coli from the freshwater environs of Calcutta, India. Microbiol Immunol 1991; 35:273-87. [PMID: 1943841 DOI: 10.1111/j.1348-0421.1991.tb01557.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
For a period of one year (March 1987 to February 1988), the incidence of Escherichia coli was determined in water, sediment and plankton collected from two sampling sites in a freshwater lake extensively used by humans and animals. Densities of E. coli associated with plankton was the lowest while sediments, especially at site 2, harbored high densities of the organism. Correlation coefficients revealed that the density of E. coli in water samples was linearly correlated to temperature, pH of water, sediment and humidity. Stepwise multiple regression analysis, however, showed that sediment temperature was the dominant variable which could explain 27% of the observed variation in the numbers of E. coli in the overlying waters (p = less than 0.001). Of the 150 environmental E. coli strains which were characterized, 31 (20.7%) were found to belong to the classic enteropathogenic E. coli (EPEC) serogroups. Seven of the serogroups among the environmental EPEC strains were also encountered from EPEC strains isolated from human cases during a concurrent clinical study. None of the 150 environmental strains were enterotoxigenic or enteroinvasive but 4 strains possessed HEp-2 cell adhesive factor. With the exception of one, all the EPEC strains isolated were multi-drug resistant. From this study, it was evident that the lake is an important source of infection of EPEC and other related diarrheagenic E. coli.
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Affiliation(s)
- A R Ghosh
- National Institute of Cholera and Enteric Diseases, Calcutta, India
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30
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West PA. The human pathogenic vibrios--a public health update with environmental perspectives. Epidemiol Infect 1989; 103:1-34. [PMID: 2673820 PMCID: PMC2249492 DOI: 10.1017/s0950268800030326] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Pathogenic Vibrio species are naturally-occurring bacteria in freshwater and saline aquatic environments. Counts of free-living bacteria in water are generally less than required to induce disease. Increases in number of organisms towards an infective dose can occur as water temperatures rise seasonally followed by growth and concentration of bacteria on higher animals, such as chitinous plankton, or accumulation by shellfish and seafood. Pathogenic Vibrio species must elaborate a series of virulence factors to elicit disease in humans. Activities which predispose diarrhoeal and extraintestinal infections include ingestion of seafood and shellfish and occupational or recreational exposure to natural aquatic environments, especially those above 20 degrees C. Travel to areas endemic for diseases due to pathogenic Vibrio species may be associated with infections. Host risk factors strongly associated with infections are lack of gastric acid and liver disorders. Involvement of pathogenic Vibrio species in cases of diarrhoea should be suspected especially if infection is associated with ingestion of seafood or shellfish, raw or undercooked, in the previous 72 h. Vibrio species should be suspected in any acute infection associated with wounds sustained or exposed in the marine or estuarine environment. Laboratories serving coastal areas where infection due to pathogenic Vibrio species are most likely to occur should consider routine use of TCBS agar and other detection regimens for culture of Vibrio species from faeces, blood and samples from wound and ear infections.
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Affiliation(s)
- P A West
- North West Water Authority, Warrington, United Kingdom
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31
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Nair GB, Oku Y, Takeda Y, Ghosh A, Ghosh RK, Chattopadhyay S, Pal SC, Kaper JB, Takeda T. Toxin profiles of Vibrio cholerae non-O1 from environmental sources in Calcutta, India. Appl Environ Microbiol 1988; 54:3180-2. [PMID: 3223774 PMCID: PMC204448 DOI: 10.1128/aem.54.12.3180-3182.1988] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
A collection of Vibrio cholerae non-O1 isolated from the aquatic environs of Calcutta, a cholera-hyperendemic area, were examined for the production of cholera toxin (CT), Shiga-like toxins (Vero toxins), heat-stable enterotoxin, and hemolysins. Two (0.5%) V. cholerae non-O1 isolates produced CT. The DNA from both these isolates also hybridized with a DNA probe containing sequences encoding the A subunit of CT. None of the strains produced Shiga-like toxins or heat-stable enterotoxin. Hemolytic activity was observed in 89.7% of the strains, of which 36.1% exhibited biological activity in the suckling mouse. However, none of them produced a hemolysin that cross-reacted with the thermostable direct hemolysin of Vibrio parahaemolyticus. It appears from this study that a small percentage of environmental V. cholerae non-O1 strains do possess the potential for causing cholera-like diarrhea.
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Affiliation(s)
- G B Nair
- National Institute of Cholera and Enteric Diseases, Calcutta, India
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