济南市食品和腹泻病人来源副溶血性弧菌分子分型及毒力基因分析

Molecular Typing and Analysis of Virulence Genes of Vibrio Parahaemolyticus Isolated from Food and Diarrhea Patients in Jinan City

目的:了解济南市动物性海产品、腹泻患者来源副溶血性弧菌的脉冲场凝胶电泳分子分型特征以及菌株携带毒力基因的情况。方法:按照《国家食品污染和有害因素风险监测工作手册》的方法采集动物性海产品150份,依据《山东省食源性疾病主动监测工作手册》采集腹泻病人样本771份,对上述两类样本进行副溶血性弧菌分离。用脉冲场凝胶电泳对129株副溶血性弧菌进行分子分型和聚类分析,利用多重荧光PCR检测菌株毒力基因的携带情况。结果:动物性海产品来源副溶血性弧菌的总检出率为41.3%,腹泻病人副溶血性弧菌的检出率为6.1%~14.2%。动物性海产品和腹泻患者来源的129株副溶血弧菌可分为93个脉冲场凝胶电泳型别,相似性系数为35.1%~100.0%。患者来源的菌株带型相似系数高于85.0%的占比为90.4%,89.3%动物性海水产品来源的菌株带型相似系数低于85.0%。73株患者来源的菌株携带tdh基因的菌株占比为95.9%,携带trh基因的菌株占比为6.8%,4.1%的菌株同时携带两个毒力基因。动物性海产品来源的56株菌均不携带毒力基因tdh,携带耐热相关溶血素的菌株占比为3.6%。结论:两种来源的菌株在分子分型和毒力基因携带方面存在差异,动物性海产品携带副溶血性弧菌的比例较高,有必要进一步加强对动物性海产品副溶血性弧菌的监测,扩大采样量并增加菌落挑取数量以进一步明确该菌株的传播、流行特征,为制定防控策略提供科学依据。

Objective:To determine the molecular typing characteristics of Vibrio parahaemolyticus from animal seafood and diarrhea patients in Jinan city and the virulence gene carried by the strains.Method:According to the methods outlined in the National Work Manual for Food Pollution and Harmful Factors Risk Monitoring,150 samples of animal-derived seafood were collected from supermarkets,retail stores,farmers’ markets,and wholesale markets.According to the Shandong Provincial Foodborne Disease Proactive Monitoring Work Manual,771 samples of diarrhea patients were collected,and Vibrio parahaemolyticus was isolated from both types of samples.Pulse field gel electrophoresis was used to perform molecular typing and cluster analysis of 129 Vibrio parahaemolyticus strains from diarrhea patients and animal aquatic products.The carrying status of the virulence genes of the two strains was detected by multiplex fluorescence PCR.Result:The total detection rate of Vibrio parahaemolyticus in animal-derived seafood was 41.3%,and the isolation rate of Vibrio parahaemolyticus in patients with diarrhea was 6.1% to 14.2%.The 129 strains of Vibrio parahaemolyticus from seafood and diarrhea patients could be divided into 93 PFGE types,with similarity coefficients ranging from 35.1% to 100.0%.90.4% of patients had strain band type similarity coefficient above 85.0%,and 89.3% of animal seawater products had strain band type similarity coefficient below 85.0%.95.9% of the 73 patient-derived strains carried the tdh gene,6.8% carried the trh gene,and 4.1% carried both virulence genes.The 49 strains from animal seafood did not carry the virulence gene tdh,and the strain carrying trh accounted for 3.6%.Conclusion:There are differences in molecular typing and virulence gene carrying between strains from two sources,the proportion of Vibrio parahaemolyticus in animal seafood is high,so it is necessary to further strengthen the monitoring of Vibrio parahaemolyticus in animal seafood,expand the sampling amount and increase the number of colonies to further clarify the transmission and epidemic characteristics of this strain,and provide a scientific basis for the development of prevention and control strategies.