Distribution of virulence markers in clinical and environmental Vibrio cholerae non-O1/non-O139 strains isolated in Brazil from 1991 to 2000.

One hundred seventy nine Vibrio cholerae non-O1/non-O139 strains from clinical and different environmental sources isolated in Brazil from 1991 to 2000 were serogrouped and screened for the presence of four different virulence factors. The Random Amplification of Polymorphic DNA (RAPD) technique was used to evaluate the genetic relatedness among strains. Fifty-four different serogroups were identified and V. cholerae O26 was the most common (7.8%). PCR analysis for three genes (ctxA, zot, ace) located of the CTX genetic element and one gene (tcpA) located on the VPI pathogenicity island showed that 27 strains harbored one or more of these genes. Eight (4.5%) strains possessed the complete set of CTX element genes and all but one of these belonged to the O26 serogroup suggesting that V. cholerae O26 has the potential to be an epidemic strain. The RAPD profiles revealed a wide variability among strains and no genetic correlation was observed.