RESUMEN
AIM: Comparative evaluation of biological properties of parahemolytic vibrios that had determined outbreaks and sporadic cases of food toxic infection in Primorsky Region in 2012 and previous years. Materials AND METHODS: 40 clinical strains of Vibrio parahaemolyticus isolated in 2012 were studied in comparison with 62 strains from this region that had been characterized by us previously. Virulence was evaluated by a complex method: hemolytic activitywas determined in Kanagawa test (KT), urease - in Kristensen medium. Serotyping was carried out by a commercial kit of O/K sera. PCR-genotyping was carried out by marker genes of 7 pathogenicity "islands" (VPaI-1-7). RESULTS: All the strains isolated from patients in 2012 had KT-positive and urease-negative phenotype, belonged to O3:K6 serogroup and contained marker genes of 7 VPal that allowed to consider them members of a "pandemic" clone as the other clinical strains from this region. However among 2012 strains an increase of number of antibiotic-resistant variants was established compared with 1997 isolates. CONCLUSION: The data obtained give evidence on the risk of spread of a "pandemic" clone of V. parahaemolyticus in the Far-Eastern region of Russia, a dangerous tendency of antibiotic-resistant variant formation and a necessity to monitor morbidity and the environment with mandatory PCR-detection of genes associated with virulence including integrated into pathogenicity "islands".
