Molecular typing on Vibrio parahaemolyticus isolates from Hangzhou, China, during 2000-2002 / 中华流行病学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the molecular epidemiology of Vibrio parahaemolyticus isolates from clinical and environmental samples collected in Hangzhou area during 2000 and 2002.</p><p><b>METHODS</b>V. parahaemolyticus isolates from food-poisoning, sporadic diarrhea patients and seafood in market in Hangzhou during 2000 and 2002 were serotyped. From clinical isolates of serotype O3K6 and environmental isolates of serotype O3KUT, virulence genes, tdh and trh, were examined by PCR. Molecular typings [including ribotyping, random amplified polymorphic DNA analysis (RAPD), enterobacterial repetitive intergenic consensus PCR (ERIC-PCR)], were also performed.</p><p><b>RESULTS</b>Among 13 food-poisoning outbreaks caused by V. parahaemolyticus, O3K6 strains with tdh positive and trh negative were detected in 11 episodes (84.6%), and O4K8 strains with tdh positive and trh negative were responsible for other 2 outbreaks (15.4%). In 34 V. parahaemolyticus isolates from sporadic diarrhea patients, O3K6, O4K8, and O1KUT strains with tdh positive and trh negative were detected with proportions of 26.5% (9/34), 17.6% (6/34), and 38.2% (13/34), respectively, and other 6 strains were not able to be serotyped. Of 64 isolates from seafood in which both tdh and trh were negative except trh was positive in one O1KUT strain, 37 belonged to 7 serotypes except O3K6 or O4K8, and 9 were not able to be serotyped. The fingprintings of ribotyping, ERIC-PCR, and RAPD showed that almost all of O3K6 isolates from food-poisoning and sporadic diarrhea patients were genetically close to each other and there were obviously genetical difference between O3K6 isolates from clinic and O3KUT isolates from environment.</p><p><b>CONCLUSION</b>There was a distinct serotype distribution between V. parahaemolyticus isolates from clinic patients and seafood. One group of close related V. parahaemolyticus O3K6 strains with tdh positive and trh negative seemed to be prevailing in Hangzhou in those years.</p>