一起食源性疾病暴发中的副溶血性弧菌病原学分析

目的 分析2016年夏季宁波市一起食源性疾病暴发中副溶血性弧菌的病原学特征。方法 采用血清凝集方法对所有分离菌株进行血清学分型。采用PulseNet China网络实验室的标准方法，对所有分离菌株进行脉冲场凝胶电泳（pulsed-field gel electrophoresis，PFGE）分型，采用BioNumerics软件对菌株PFGE指纹图谱进行聚类分析；实时荧光PCR方法用于检测菌株的tdh、trh和tlh基因，MIC法检测菌株对10种抗生素的耐药性。结果 从腹泻患者粪便标本共分离到8株副溶血性弧菌。血清学分型鉴定为2株O3:K6型，6株O4:KUT型。所有菌株经SfiⅠ、NotⅠ酶切后分别分为3个和4个PFGE带型。VPAN11.ZJNB002/VPAS12.ZJNB002带型为最优势型，共4株细菌。副溶血性弧菌对10种选定的抗生素均敏感。结论 这是一起由混合血清型，并对应多种PFGE带型的多克隆副溶血性弧菌引起的食源性疾病暴发事件，应提高对多克隆副溶血性弧菌引起的混合感染性食物中毒的认识水平，防止漏检。未发现菌株对10种选定的抗生素产生耐药。

Etiology of a Vibrio parahemolyticus caused foodborne-disease outbreak

Objective To analyze the etiological characteristics of a Vibrio parahemolyticus caused foodbome-disease outbreak in Ningbo in summer,2016.Methods The V.parahemolyticus strains isolated in a foodbome-disease outbreak were serotyped and their susceptibilities to 10 antibiotics were detected.Real time fluorescence quantitative PCR was used to detect the tdh,trh and tlh genes.The cluster analysis of the 8 V.parahemolyticus strains were performed by using pulsed-field gel electrophoresis (PFGE).Results A total of 8 V.parahemolyticus strains were isolated from the stool samples of diarrhea patients.Serological analysis of O and K antigens indicated that 2 strains were identified as O3∶ K6,and 6 strains were identified as O4∶ KUT.The 8 V.parahemolyticus strains were subtyped into 4 PFGE patterns by NotⅠ digestion or 3 PFGE patterns by SfiⅠ digestion.Subtype VPAN11.ZJNB002 (VPAS12.ZJNB002) was predominant,including 4 strains.All the strains were sensitive to piperacillin/ tazobactam,ceftriaxone,cefepime,aztreonam,imipenem,amikacin,gentamicin,ciprofloxacin,levofloxacin and SMZ.Conclusion This foodborne-disease outbreak was caused by polyclone V.parahemolyticus strains,including at least 2 serotypes or 4 PFGE patterns.Close attention should be paid to the co-infection with polyclone V.parahemolyticus to avoid missed detection.No antibiotic resistance was found in drug susceptibility test of the 8 strains.