舟山市售毛蚶中创伤弧菌的定量检测及毒力基因分析

Quantitative detection and virulence gene analysis of vibrio vulnificus in clam on Zhoushan markets

目的为了解舟山市场毛蚶中创伤弧菌的污染状况,对食用毛蚶的危险性评估提供科学依据。方法从舟山市区的三大菜场分季节共采集79份毛蚶样本进行创伤弧菌的定量检测和分子生物学鉴定,并应用SPSS 13.0统计软件包对检出的数据进行χ2检验分析,以P<0.05为差异有统计学意义。结果 79份毛蚶的创伤弧菌全年平均检出率为41.8%,夏季的检出率高达84.8%,每克样本中最大可能数(MPN)平均值为2 029MPN/g,最高MPN值为24 000MPN/g。所有创伤弧菌菌株均为溶血素A基因(vvhA)核酸阳性。检出1株生物Ⅱ型,其余均为生物Ⅰ型,其中有1株SerE核酸阳性。vcgC/E和16SrRNA A/B分型结果显示共有3种基因型别,其中vcgC/16SrRNA B(CB)型为主要基因型,占75.0%。结论舟山市场的毛蚶中创伤弧菌污染比较严重,有必要加强监测,对毛蚶进行安全性评估,预防食源性疾病和相关疾病的暴发。

Objective To understand the contamination status of clam with Vibrio vulnificus sold on markets,and to analyze the virulence gene of Vibrio vulnificus.Methods 79 clam samples were collected from three markets in Dinghai during each season from 2010 to 2011 for quantitative detection,molecular biological identification and genotyping of Vibrio vulnificus.SPSS 13.0 software was used to analyze the data.Results Out of 79 samples,the average annual detection rate of Vibrio vulnificus was 41.8% with the highest of 84.8% in summer.The mean and maximum MPN values were 2 029 and 24 000 in 1g samples.All isolates of Vibrio vulnificus were found to harbor hemolysis A gene（vvhA）.Almost all strains were type I except for one of type II.The result of genotyping showed that vcgC/16S rRNA B was dominant accounting for 75%.Conclusions The situation of clam contaminated with Vibrio vulnificus sold on Zhoushan markets is bad,therefore,safety evaluation and surveillance for clam in markets are critical to prevent the outbreaks of food-borne diseases.