Virulence Genes in Environmental Strains of Vibrio cholerae
IR@IICB: CSIR-Indian Institute of Chemical Biology, Kolkata
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| Title |
Virulence Genes in Environmental Strains of Vibrio cholerae
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| Creator |
Chakraborty, Soumen
Mukhopadhyay, Asish K Bhadra, Rupak K Ghosh, Amar Nath Mitra, Rupak Shimada, Toshio Yamasaki, Shinji Faruque, Shah M Takeda, Yoshifumi Colwell, Rita R Nair, G Bbalakrish |
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| Subject |
Infectious Diseases and Immunology
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| Description |
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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| Publisher |
American Society for Microbiology
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| Date |
2000
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://www.eprints.iicb.res.in/801/1/APPLIED_AND_ENVIRONMENTAL_MICROBIOLOGY_66(_9)_4022%2D4028;2000[18].pdf
Chakraborty, Soumen and Mukhopadhyay, Asish K and Bhadra, Rupak K and Ghosh, Amar Nath and Mitra, Rupak and Shimada, Toshio and Yamasaki, Shinji and Faruque, Shah M and Takeda, Yoshifumi and Colwell, Rita R and Nair, G Bbalakrish (2000) Virulence Genes in Environmental Strains of Vibrio cholerae. Applied and Environmental Microbiology, 66 (9). pp. 4022-4028. |
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| Relation |
http://dx.doi.org/10.1128/AEM.66.9.4022-4028.2000
http://www.eprints.iicb.res.in/801/ |
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