Phenotypic and Genetic Analysis of Altered Variants of Vibrio cholerae Biovar El Tor
https://doi.org/10.21055/0370-1069-2012-1(111)-57-61
Abstract
Determined is cholera toxin production by altered Vibrio cholerae O1 eltor strains, isolated on the territory of Russia in 1993-2010, which contain classical type ctxB gene. Studied are their genetic characteristics related to the production of this virulence factor. Determined is that altered eltor variants yield 10 to 20 times more cholera toxin than typical eltor strains. Changes in promotor region of ctxAB operon are not detected but elucidated is that 90 % of studied altered strains contain two copies of CTXϕ prophage in their genome whereas typical strains carry one copy of CTXϕ prophage. Despite the higher copy number of CTXϕ prophage, the identified differences in production of cholera toxin can be associated mostly with a change of transcriptional activity of regulatory genes. That causes the active production of cholera toxin by the altered variants of Vibrio cholerae eltor in non typical environment.
About the Authors
S. P. Zadnova
Russian Research Anti-Plague Institute Microbe
Russian Federation
Russian Federation
A. V. Shashkova
Russian Research Anti-Plague Institute Microbe
Russian Federation
Russian Federation
Ya. M. Krasnov
Russian Research Anti-Plague Institute Microbe
Russian Federation
Russian Federation
N. I. Smirnova
Russian Research Anti-Plague Institute Microbe
Russian Federation
Russian Federation
References
1. Baroyan O.V. [Cholera El Tor]. M.: Meditsina; 1971. P. 256.
2. Gintsburg A.L., Yanishevsky, N.V., MotinV.L., Shaginyan I.A., Vertiev Yu.V., Smirnov G.B. [Arrangement and cloning of Vibrio cholerae El Tor RV79 structure genes of enterotoxin]. Mol. Genet. Microbiol. Virusol. 1984; 9:12–8. 3. Laboratory diagnostics of cholera. MUK 4.2.2218-07. M.; 2007. 87 p.
3. Maniatis T., Fritsch E., Sambrook J. [Molecular Cloning: A Laboratory Manual]. M.: Mir; 1984. 480 p.
4. Smirnova N.I., Goryaev A.A., Zadnova S.P., Krasnov Ya.M., Lozovskiy Yu.V., KutyrevV.V. [Genetic characterization of Vibrio cholerae strains emerging in Russian Federation during 7th cholera pandemic]. Mol. Genet. Mikrobiol. Virusol. 2011; 3:8–11.
5. DiRita V.J., Neely M., Taylor R.K., Bruss P.M. Differential expression of the ToxR regulon in classical and El Tor biotypes of Vibrio cholerae is due to biotype-specific control over toxT expression. Proc. Natl. Acad. Sci. USA. 1996; 93(15):7991-5.
6. Ghosh-Banerjee J., Senoh M., Takahashi T., Hamabata T., Barman S., Koley H. et al. Cholera toxin production by the El Tor variant of Vibrio cholerae O1 compared to prototype El Tor and classical biotypes. J. Clin. Microbiol. 2010; 48(11):4283-6.
7. Iwanaga M., Yamamoto K., Higa N., Ichinose Y., Nakasone N., Tanabe M. Culture conditions for stimulating cholera toxin production by Vibrio cholerae O1 El Tor. Microbiol. Immunol. 1986; 30(11):1075-83.
8. Kaper J.B., Morris J., Levin M. Cholera. Clin. Microbiol. Rev. 1995; 8(1):48-89.
9. Lee J.H., Choi S.Y., Jeon Y-S., Lee H.R., Kim E.J., Nguyen B.M. et al. Classification of hybrid and altered Vibrio cholerae strains by CTX prophage and RS1 element structure. J. Microbiology. 2009, 47(6):783-8.
10. Mekalanos J.J. Duplication and amplification of toxin genes in Vibrio cholerae. Cell. 1983; 35(1):253-63.
11. Mekalanos, J.J., Swartz D.J., Pearson G.D.N., Harford N., Groyne F., de Wilde M. Cholera toxin genes: nucleotide sequence, deletion analysis and vaccine development. Nature. 1983; 306:551-7.
12. Miller V.L., Mekalanos J.J. A novel suicide vector and its use in construction of insertion mutations: osmoregulation of outer membrane proteins and virulence determinants in Vibrio cholerae requires toxR. J. Bacteriol. 1988; 170(6):2575-83.
13. Nair G. B., Qadri F., Holmgren J., Svennerholm A.M., Safa A., Bhuiyan N.A. et al. Cholera due to altered El Tor strains of Vibrio cholerae O1 in Bangladesh. J. Clin. Microbiol. 2006, 44:4211-3.
14. Safa A., Nair G.B., Kong R.Y. Evolution of new variants of Vibrio cholerae O1. Trends Microbiol. 2010; 18(1):46-54.
15. Svennerholm A.M., Wiklund G. Rapid GM1-enzyme-linked immunosorbent assay with visual reading for identification of Escherichia coli heat-labile enterotoxin. J. Clin. Microbiol. 1983; 17(4):596-600.
Review
For citations:
Zadnova S.P., Shashkova A.V., Krasnov Ya.M., Smirnova N.I. Phenotypic and Genetic Analysis of Altered Variants of Vibrio cholerae Biovar El Tor. Problems of Particularly Dangerous Infections. 2012;(1(111)):57-61. (In Russ.) https://doi.org/10.21055/0370-1069-2012-1(111)-57-61
Views:
828
Email this article 