[Studies on Vibrio vulnificus infection: molecular epidemiology of environment-derived strains and clinical isolates]

To clarify the route and source of Vibrio vulnificus infection, we conducted molecular epidemiological investigation by DNA analysis of 355 environmental isolates (seawater-derived strain: 86, sea mud-derived strain:36, and oyster-derived strain: 233) and 65 human clinical isolates, for a total of 420 isolates, using pulse field gel electrophoresis (PFGE), with the following results. 1. When DNA was cleaved with 2 enzymes, Not I and Sfi I, and subjected to PFGE, Not I DNA interpretation was 76.9%, and Sfi I cleavage was 97.9%, showing that Sfi I was superior in cleaving DNA of this bacteria. 2. Sfi I-interpreted strains were subjected to PFGE and migration patterns were analyzed by UPGMA, but close classification was not possible because similarity was low, this infectious disease clearly originated from multiple rather than a single-clone. In this cluster, we concluded that this infectious disease was acquired through contact between the environment and human beings and viceversa. We identified an assortment of clinical isolates and environment-derived strains among more than 89% of strain groups tested, none of which could be expected to have the same origin. We conclued DNA analysis on these two types of restriction enzymes using PFGE, but were unable to classify test results in detail due to the proliferation of migration patterns and low degree of similarity.