The use of genetic typing methods to discriminate among strains of Vibrio cholerae, V. parahaemolyticus, and V. vulnificus.

This review article summarizes the findings of recent typing studies conducted on Vibrio cholerae, V. parahaemolyticus, and V. vulnificus. The DNA-based methods used to type the Vibrio spp. include whole genome approaches, such as pulsed field gel electrophoresis (PFGE), ribotyping, and repetitive extragenic palindromic (REP)-PCR, single gene targets, and multiple gene targets (multilocus approaches). The goals of these studies include establishing the relatedness of isolates from disease epidemics, discriminating among strains with more or less potential to cause disease or epidemics, and exploring the population biology of these waterborne pathogens. PFGE was consistently among the more discriminatory of the typing methods for all three Vibrio spp., and was useful for tracing the temporal and geographic relatedness of epidemic strains of V. cholerae and V. parahaemolyticus. However, PFGE did not group V. vulnificus strains according to the genotypes that have been proposed as markers of virulence potential. Typing methods that target repetitive elements distributed throughout the genome, such as BOX-PCR and REP-PCR, and DNA sequence-based methods, such as multilocus sequence typing, were also highly discriminatory and, in some cases, superior to PFGE for phylogenetic analysis and identification of strains with high epidemic or virulence potential. As typing methods and strategies are refined and used, the epidemiology, virulence potential, and ecology of these pathogenic Vibrio spp. will become better understood.