一起副溶血性弧菌食物中毒的病原学分析及分子分型溯源研究  

Etiological analysis and molecular typing and traceability of Vibrio Parahaemolyticus in a food poisoning event

作　　者：刘思超[1] 罗泽燕[1] 徐励琴[1] 杨剑英[1] 冯伟明[1] 苗思慧[1] LIU Si-chao;LUO Ze-yan;XU Li-qin;YANG Jian-ying;FENG Wei-ming;MIAO Si-hui.(Huizhou Center for Disease Control and Prevention, Huizhou 516003, China)

机构地区：[1]惠州市疾病预防控制中心,广东惠州516003

出　　处：《华南预防医学》2018年第2期128-133,共6页South China Journal of Preventive Medicine

摘　　要：目的对1起食物中毒事件分离的副溶血性弧菌进行病原学检测及分子分型溯源研究。方法按照《食品安全国家标准食品微生物学检验副溶血性弧菌检验》GB 4789.7—2013对事件中病例的粪便/肛拭子、可疑食物等10份样本进行副溶血性弧菌的分离和鉴定。利用荧光PCR对分离出的副溶血性弧菌特异的ToxR基因进行检测,并采用多重荧光PCR对其进行不耐热性溶血毒素(tlh)、耐热直接溶血素(tdh)毒力基因和耐热相关溶血素(trh)毒力基因进行检测;采用脉冲场凝胶电泳(PFGE)技术进行电泳获得指纹图谱,并经Bio Numerics软件对其进行聚类分析。结果从4例病例的粪便/肛拭子和2份可疑食物样本中共分离出6株副溶血性弧菌,含5种血清型,分别为O1:KUT、O1:KUT、O3:K6、O4:KUT、OUT:KIII、O3:KUT。6株副溶血性弧菌均扩增出副溶血性弧菌特异的ToxR基因。所有菌株tlh基因均为阳性,分离自病例的粪便/肛拭子的4株菌株tdh毒力基因均为阳性;分离自可疑食物的2株菌株中有1株为tdh毒力基因阳性,另1株为阴性;所有分离菌株trh毒力基因均为阴性。聚类分析显示,菌株间相似系数为62.3%~100.0%。分离自可疑食物的菌株与病例的菌株带型不一致,为不同菌株,分离自病例的同一血清型的菌株同源,不同血清型为不同克隆。结论这是1起由携带tdh毒力基因的O1、O3、O4等多种血清型的不同克隆副溶血性弧菌混合感染引起的食物中毒事件。Objective To study the etiological analysis and molecular typing and traceability of Vibrio Parahaemolyticus isolated from a food poisoning event. Methods According to ＂National food safety standard for food microbiological test： Vibrio Parahaemolyticus ＂ GB 4789.7 -2013, specimens from the patients＇stool, anal swabs and suspicious food in a food poisoning event were tested for Vibrio Parahaemo- lyticus. The strains isolated were tested for ToxR by real-time fluorescence PCR, and then the virulence gene of thermolabile hemolysin （ tlh）, thermostable direct hemolysin （tdh） and thermostable related hemo- lysin （trh） were tested by using multiplex fluorescent PCR. Electrophoresis fingerprints were obtained by pulsed field gel electrophoresis （PFGE） technique and the clustering analysis was performed by BioNumer- ics software. Results Six strains of Vibrio Parahaemolyticus were isolated from 4 patients＇stooL/anal swabs and 2 suspicious food. The serotypes were O1： KUT, O1： KUT, O3K6, 04： KUT, OUT： KIII, and O3 ： KUT, respectively. The specific ToxR gene was amplified from 6 strains of Vibrio Parahaemolyticus, all of which were positive for tlh gene. The 4 strains isolated from patientg stooL/anal swabs were positive for the tdh virulence genes. One of 2 strains from the suspicious food was positive for tdh virulence gene. All strains were negative for trh virulence gene. Cluster analysis showed that the similarity of the strains was from 62. 3% to 100.0%. The finger prints of strains isolated from suspicious food were different from thoseof strains from the specimens of the patients. Hence, they were different strains. The strains from patients with the same serotype were homologous in cloning. The strains belonging to different serotypes were differ- ent clones. Conclusion The food poisoning event was caused by the mixed infection of different clones of Vibrio Parahaemolyticus, carrying the tdh virulence genes, with serotypes of O1, O3, and O4.

关 键 词：食物中毒 弧菌 副溶血 电泳 凝胶 脉冲场 

分 类 号：R155.51[医药卫生—营养与食品卫生学]