ENTEROBACTERIAL REPETITIVE INTERGENIC CONSENSUS SEQUENCES AND THE PCRTO GENERATE FINGERPRINTS OF GENOMIC DNAS FROM VIBRIO-CHOLERAE O1, O139, AND NON-O1 STRAINS

Enterobacterial repetitive intergenic consensus (ERIC) sequence polymo rphism was studied in Vibrio cholerae strains isolated before and afte r the cholera epidemic in Brazil (in 1991), along with epidemic strain s from Peru, Mexico, and India, by PCR, A total of 17 fingerprint patt erns (FPs) were detected in the V. cholerae strains examined; 96.7% of the toxigenic V. cholerae 01 strains and 100% of the 0139 serogroup s trains were found to belong to the same FP group comprising four fragm ents (FP1). The nontoxigenic C cholerae O1 also yielded four fragments but constituted a different FP group (FP2), A total of 15 different p atterns were observed among the V. cholerae non-O1 strains, Two patter ns were observed most frequently for V. cholerae non-O1 strains, 25% o f which have FP3, with five fragments, and 16.7% of which have FP4 wit h two fragments, Three fragments, 1.75, 0.79, and 0.5 kb, were found t o be common to both toxigenic and nontoxigenic V. cholerae O1 strains as well as to group FP3, containing V. cholerae non-O1 strains. Two fr agments of group FP3, 1.3 and 1.0 kb, were present in FP1 and FP2, res pectively, The 0.5-kb fragment was common to all strains and serogroup s of V. cholerae analyzed, It is concluded from the results of this st udy, based on DNA FPs of environmental isolates, that it is possible t o detect an emerging virulent strain in a cholera-endemic region, ERIC -PCR constitutes a powerful tool for determination of the virulence po tential of V. cholerae O1 strains isolated in surveillance programs an d for molecular epidemiological investigations.