不同来源副溶血性弧菌分离株分子特征和耐药性研究

Study on molecular characteristics and antibiotic resistance of Vibrio parahaemolyticus isolates

目的:对副溶血性弧菌食品分离株和病人分离株的血清群分布、产毒素特性及耐药性进行比较,分析两种菌株的差异性。为防治副溶血性弧菌引起的食源性疾病提供依据。方法:用国标法分离鉴定副溶血性弧菌;用标准血清进行分群;运用PCR技术进行耐热溶血毒素基因(tdh)和耐热溶血毒素相关溶血素基因(trh)检测;并进行肠道细菌重复基因间共同序列PCR(ERIC-PCR)分析;用纸片扩散法进行药敏试验。结果:从病人分离的32株副溶血性弧菌属于2个血清群,分别为0:3群占84.4%、0:5群占15.6%。tdh阳性9株,阳性率28.1%,trh均阴性。从食品分离的22株副溶血性弧菌分属于5个血清群,分别为0:3群占40.9%、0:4群占22.7%、0:2群占13.6%、0:5群占9.1%、0:6群占4.6%、0:8群占9.1%。22株副溶血性弧菌的tdh与trh毒力基因均阴性。药敏试验结果显示:食品分离株与病人分离株副溶血性弧菌对青霉素类、B-内酰胺类、氨基糖苷类、磺胺类、喹诺酮类、头孢类药物都有耐药株出现。结论:宁波市副溶血性弧菌食品分离株与病人分离株分型、毒力基因的携带率存在一定的差异性,但主要为O:3群。药敏结果出现多重耐药的特点。

Objective ：To compare the serotypes, virulence -production and antibiotic resistances of Vibrio parahaemolyticus isolated from food and patients and to provide theoretical basis to control the food - borne diseases caused by Vibrio parahaemolyticus. Methods：Isolation and identification of Vibrio parahaemolyticus was carried out with the method according to national standards. Serotyping was done with antiserum against these organisms. Heat - resistant hemolytic （tdh） virulence gene and heat - resistant gene - related hemolytic （trh） toxin gene were detected with PCR. Enterobacterial repetitive intergenic consensus PCR （ERIC- 19CR） was performed to analyze the relationship among these isolates. Autimicrobial susceptibility was determined with disk diffusion method. Results： There are 2 serotypes in 32 isolates from patients： group 0：3 and group 0：5 accounting for 84.4% and 15.6% respectively. Nine isolates are tdh gene positive （28. 1% ）. No trh gene was detected. While 2.2 isolates from food sources can be divided into 5 serotypes： 0 ：3, 0：4, 0：2, 0 ：5, 0 ：6, and 0：8 accounting for 40.9%, 22.7%, 13.6%, 9.1%, 4. 6% and 9. 1% respectively. No tdh gene and trh gene were detected. Drug resistance against penicillins, β - lactams, aminoglycosides, sulfonamidcs, quinolones and cephalosporins was found in isolates both from food and patients. Conclusion： Difference exists in serotyping and carrying rate of virulence gene between isolates from food and those from patients in Ningbo. The dominant serutype is 0 ：3. Susceptibility shows multi -drug resistance in some isolates.