2009～2011年无锡市副溶血性弧菌分离菌株的毒力检测及PFGE分析

Detection of virulence factors and pulsed field gel electrophoresis analysis of Vibrio parahaemolyticus isolated from Wuxi from 2009-2011

目的了解无锡市2009～2011年副溶血性弧菌分离株携带的主要毒力因子的流行状况,并对同血清型菌株进行脉冲场凝胶电泳(PFGE)分析。方法应用PCR方法检测分离的35株副溶血性弧菌耐热性溶血毒素基因(tdh)、耐热性溶血毒素相关的溶血毒素基因(trh)和不耐热溶血毒素基因(tlh)。根据美国CDC PulseNet实验方法,用限制性内切酶SfiⅠ对O3﹕K6血清型菌株的染色体进行酶切,通过PFGE获得电泳图谱,利用BioNumerics软件对图谱进行聚类分析。结果 35株副溶血性弧菌tdh、trh及tlh基因的携带率分别为85.7%、8.6%和100%,77.1%的副溶血性弧菌携带的毒力基因为tdh+、trh-、tlh+。PFGE图谱显示,19株O3﹕K6血清型的副溶血性弧菌共有9种PFGE带型,带型100%相同的菌株几乎都出现在同一年代相近的时间点,但也出现了跨年代菌株。结论无锡市副溶血性弧菌致病性较强,具有潜在的O3﹕K6型副溶血性弧菌暴发流行可能,需进一步加强监测管理。

Objectives To investigate the prevalence of virulence factors possessed by Vibrio parahaemolyticus and to molecularly type homologous serotype strains isolated from Wuxi from 2009-2011.Methods PCR was used to detect tdh,trh,and tlh virulence genes of the 35 strains of V.parahaemolyticus,and pulsed field gel electrophoresis（PFGE） was used to molecularly type O3： K6 serotype strains in accordance with the laboratory directions for molecular typing of V.parahaemolyticus using PFGE（PulseNet,USA）.Cluster analysis was done with BioNumerics software.Results The distribution of the tdh,trh,and tlh virulence genes among the 35 strains was 85.7%,8.6%,and 100%.About 77.1% of isolates were tdh＋,trh-,and tlh＋.PFGE divided 19 strains of V.parahaemolyticus of O3： K6 serotype into 9 different genotypes,and strains with a 100% identical genotype appeared at similar times during the period studied.Conclusion V.parahaemolyticus strains in Wuxi are highly pathogenic,and the O3： K6 serotype strains have the potential to cause an outbreak.Surveillance of V.parahaemolyticus needs to be enhanced.