Molecular characteristic of dominant serotypes of Vibrio parahaemolyticus isolated from foodborne disease outbreaks in Guangdong province / 中华微生物学和免疫学杂志

ABSTRACT

ObjectiveTo study the toxin genes and pandemic group distribution as well as the genetic correlation between the major serotypes( O3K6,O1Kut,O4K8 ) of Vibrio parahaemolyticus (VP) isolated from the outbreaks of Guangdong province.MethodsThe tdh and trh genes,GS-PCR and orf8 gene were detected on the 62 isolates sourced from patient and seafood occurred in the 23 outbreaks during 2008-2010.44 isolates of which were analyzed on PFGE digested by Not Ⅰ enzyme.ResultsToxin genes distributions suggested that 96.8% (60/62)isolates were tdh+,trh-.Three tdh+ isolates sourced from seafood were found.Pandemic group distribution suggested that 97.2% (35/36) O3K6,5.88% (1/17) O4K8,66.7% (8/9)O1Kut serotype was GS-PCR+ and/or orf8+,respectively.PFGE analysis suggested that 44 isolates were separated into 3 clusters,of which the similarity of PFGE profile was 80.5% in the pandemic group cluster constructed by 28 isolates,the similarity between pandemic group and non-pandemic group was 59.5%.Pandemic group of O3K6,O1Kut as well as 04K8 isolated on some outbreaks were processing the same PFGE profiles.ConclusionThe characteristic of toxin genes of major serotypes VP isolated in the outbreaks of Guangdong province form 2008-2010 was tdh- present and trh- absent.Within the pandemic group,O3K6 and O1Kut were the major serotypes.In single outbreak,isolates belongs to pandemic group but with different serotype seem to be close correlations.