Investigation of the 1994-5 Ukrainian Vibrio cholerae epidemic using molecular methods

Thirty-seven Vibrio cholerae and four non-cholera Vibrio isolates from Ukraine, including strains from the epidemic of 1994-5, were analysed by molecular methods. Results from PFGE and ribotyping indicated that all Ukrainian toxigenic V. cholerae were closely related to each other and to an isolate from a patient from Pakistan. A non-toxigenic river water strain obtained during the height of the epidemic was more distantly related to these V. cholerae strains, while the Vibrio parahaemolyticus isolates and Vibrio alginolyticus isolate were not closely related to V. cholerae or each other. ERIC- and REP-PCR allowed the differentiation of strains identical by other methods. The results obtained confirm that the epidemic Ukrainian strains are most closely related to seventh pandemic strains from Asia and support a hypothesis that the Ukrainian epidemic of 1994-5 was caused by toxigenic environmental strains surviving since the time of the 1991 Ukrainian epidemic or before.