Ribotyping of clinical Vibrio vulnificus isolates

Restriction fragment length polymorphism analysis of rRNA genes (ribotyping) was used to differentiate Vibrio vulnificus isolates. Among the 10 restriction enzymes tested, HindIII was shown to provide the most discriminatory patterns. Stul was used for further analysis of strains that were indistinguishable with HindIII. Thirteen clinical V. vulnificus strains were analyzed for their ribotypes with HindIII, as well as Stul when necessary. Four of the clinical strains were isolated from different samples collected from the same patient, and were shown to have identical ribotypes. All the others gave unique ribotypes, indicating the large genetic divergence in V. vulnificus clinical isolates. The ribotype of V. vulnificus by HindIII remained unchanged after successive in vitro and in vivo passages. HindIII gave rise to five bands which were shown in every V. vulnificus strain but not in other vibrio species tested, suggesting that ribotyping with this restriction enzyme may be useful for confirming the identification of this bacterium.