肇庆市副溶血性弧菌血清型、毒力基因和脉冲场凝胶电泳分子分型研究

Serotype,virulence genes and pulsed-field gel electrophoresis molecular typing of Vibrio parahaemolyticus in Zhaoqing City

目的通过副溶血性弧菌血清型、毒力基因和脉冲场凝胶电泳(PFGE)分子分型研究,建立肇庆市副溶血性弧菌DNA指纹图谱基因库。方法对肇庆市食物中毒分离出的28株副溶血性弧菌和食品安全风险监测的各类水产品分离的17株副溶血性弧菌进行血清分型,耐热直接溶血素相关基因(trh)和耐热直接溶血素基因(tdh)PCR检测,对45株副溶血性弧菌进行PFGE分子分型。结果食物中毒分离的28株副溶血性弧菌,血清型以O_4:K_8(32.14%)和O_3:K_6(25.00%)为主,17株水产品分离的副溶血性弧菌,血清型以O_1:K_(UT)(42.11%)为主;21株(46.67%)为tdh^+trh^-菌株,23株(51.11%)为tdh^-trh^-菌株,1株(2.22%)为tdh^-trh^+。45株副溶血性弧菌的PFGE相似值为3.9%～100.0%,被分为36种不同的PFGE型别,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。结论肇庆市食物中毒的副溶血性弧菌以O_4:K_8和O_3:K_6血清型为主,多数菌株携带tdh基因。PFGE结果提示肇庆市流行的副溶血性弧菌存在多克隆来源。

Objective To establish DNA fingerprint databases of Vibrio parahaemolyticus in Zhaoqing City through analyzing its serotype,virulence genes and pulsed-field gel electrophoresis（ PFGE） molecular typing. Methods Twenty-eight Vibrio parahaemolyticus strains from food poisoning cases and 17 Vibrio parahaemolyticus strains from food safety risk monitoring of different seafood in Zhaoqing City were serotyped and detected for thermostable direct hemolysin gene（ tdh） and TDH-related hemolysin gene（ trh） by PCR. 45 sero-variant Vibrio parahaemolyticus strains were selected through PFGE subtyping. Results O4： K8（ 32.14%） and O3： K6（ 25.00%） were the predominant serotypes of the 28 Vibrio parahaemolyticus strains isolated from food poisoning cases,while O1： K（UT）（ 42.11%） was the predominant serotype of the 17 Vibrio parahaemolyticus strains separated from different seafood. There were 21（ 46.67%） tdh^＋trh^-,23（ 51.11%） tdh^-trh^-,and 1（ 2.22%） tdh^-trh^＋strans. The similarity value of the 45 strains subtyped by PFGE method was between 3. 9% and 100%,and 36 PFGE subtypes were identified. Strains with a100% identical genotype appeared almost synchronously during the period studied. Conclusions O4： K8 and O3： K6 were the most dominant serotypes in Vibrio parahaemolyticus strains from food poisoning cases in Zhaoqing City,and tdh was detected in most of the strains. The prevalent Vibrio parahaemolyticus strains in Zhaoqing City had various sources of clones.