上海市水产品副溶血性弧菌的污染情况及毒力基因分布

Detection of Vibrio parahaemolyticus and Virulence Genes Isolated from Seafood in Wharf and Market of Shanghai

副溶血性弧菌是引起沿海城市食源性疾病爆发的主要致病菌之一。为了调查2015年7月-2016年6月上海市内水产品中副溶血性弧菌的污染情况及毒力菌株的分布,根据GB/T4789. 2013《食品卫生微生物学检验副溶血性弧菌检验》方法结合聚合酶链式反应及环介导等温扩增技术,从206份水产样品中分离出201株疑似副溶血性弧菌,挑取疑似菌株接种至科玛嘉弧菌显色培养基并获取最大可能数,提取菌株基因组DNA对其进行毒力基因鉴定。从上海芦潮港码头收集71份样品中,有59份样品中分离出副溶血性弧菌,污染量为88.36 MPN/hg。上海市水产市场采样副溶血性弧菌污染率高达91.11%,污染量为1 361.76 MPN/hg。其中,tdh、trh阳性菌株污染率分别为1.6%、1.0%,均分离自虾中。研究表明,上海市售水产品中虾类是总副溶血性弧菌及致病性副溶血性弧菌污染率最高的水产品种类。水产品市场相对于自然环境而言具有更高的污染率和污染量,水产品捕捞后的一系列操作增加了副溶血性弧菌的污染。这些结果为上海市食源性疾病的防控提供了依据。

Vibrio p arahae moly tic us is an intracellular pathogen responsible for seafood-bome outbreaks in coastal cities.The aim of this study was to investigate the profiles of V.parahaemolyticus in seafood from Shanghai in 2015-2016.201 suspected V.parahaemolyticus strains were isolated from 206 aquatic samples by rapid separable and detectable assays,including GB/T4789.2013,polymerase chain reaction(PCR)and loop-mediated isothermal amplification(LAMP).Suspected colonies were streaked onto CHROMagar Vibrio agar plate to determine the most probable number(MPN).DNA from the purple colonies was extracted for use as a template for PCR and LAMP detection.A total of 71 samples were collected from the sea wharf,59 of these samples were tested positive for V.parahaemolyticus with levels as high as 88.36 MPN/hg.In contrast,the prevalence rate was 91.11%with levels as high as 1 361.76 MPN/h g for samples collected in the marketplace.The prevalence rates of tdh^+and trh^+were 1.6%,1.0%respectively.These results showed that shrimp was a particular concern for total V.p arahae molytic us and V.parahaemolyticus(tdh^/trh+)contamination.Furthermore,the seafood marketplace has a higher contamination rate than natural environment.As shown in this study,the post-harvest practices increase the prevalence rate and level of V.parahaemolyticus in seafood.These results can be used to control outbreak of foodbome diseases in Shanghai.