Phenotypic and genetic characteristics of Vibrio cholerae O1 carrying Haitian ctxB and attributes of classical and El Tor biotypes isolated from Silvassa, India.

Phenotypic and genetic characteristics of Vibrio cholerae O1 carrying Haitian ctxB and attributes of classical and El Tor biotypes isolated from Silvassa, India. J Med Microbiol. 2016 May 27; Authors: Das MM, Bhotra T, Zala D, Singh DV Abstract Vibrio cholerae O1 biotype El Tor, the causative agent of the 7th pandemic, has recently been replaced by strains carrying classical and Haitian ctxB in India, Haiti and other parts of the world. We conducted phenotypic and genetic tests to characterize V. cholerae O1 isolated between 2012 and 2014 from Silvassa, India, to examine the presence of virulence and regulatory genes, seventh pandemic marker, ctxB type and biofilm formation and to study genomic diversity. Of the 59 V. cholerae O1, eight isolates belong to El Tor prototype, one to classical prototype and the remaining isolates had attributes of both classical and El Tor biotypes. PCR and ctxB gene sequencing revealed the presence of classical ctxB in four strains and Haitian ctxB in 55 isolates; indicating isolates were either El Tor or hybrid variant. All isolates carried virulence, regulatory, adherence, VSP-I, and seventh pandemic group specific marker VC2346, in addition to, tcpAET and rstRET, the features of seventh pandemic strains, and produced cholera toxin and biofilm. PFGE analysis showed that majority isolates are clonal and belong to fingerprint pattern A; however, pattern B is unrelated, and pattern C and D are distinct, ...
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research