<i>Vibrio cholerae</i> Genome Evolution: Ways of Atypical Strains Formation

Abstract

Presented is the review of literarary and authors` data on the ways of emergence of Vibrio cholerae eltor strains, atypical as regards their virulence properties. The enhancement of virulence of cholera eltor agent at present was shown to be associated with acquisition of Vibrio cholerae cholerae CTXφ prophage as a result of horizontal gene transfer. Another possible way of formation of strains with higher virulence is described - alteration of cholera toxin resident genes regulation due to rearrangement of CTXφ prophage genome by the introduced transposon. Also considered are evidences on origination of ctxA- tcpA+ strains and their enhanced viability in aquatic environment as compared with isogenic toxinogenic clones. Presented are the prospects of the development of new PCR test for detection of cholera eltor agent with altered virulence in monitoring investigations.

Keywords

• vibrio cholerae
• evolution
• genome
• ctxφ prophage
• virulence
• cholera toxin
• pandemics