广州市一起非O1/O139群霍乱弧菌食物中毒分离株的病原特征分析

目的 了解2014年广州市某工厂发生的一起非O1/O139群霍乱弧菌食物中毒分离株的耐药特性及分子特征。方法 对分离到的6株非O1/O139群分离株进行生化鉴定、血清学鉴定、药物敏感性实验、毒力相关基因检测和脉冲场凝胶电泳（PFGE）分子分型分析。结果 6株分离株经生化鉴定、血清学鉴定为非O1/O139群。药物敏感性分析显示，6株分离株均对氨苄西林、头孢克肟、头孢拉定、阿米卡星、妥布霉素、庆大霉素和多粘菌素B耐药，对诺氟沙星、环丙沙星、复方新诺明、呋喃唑酮、四环素、吡哌酸、红霉素和氯霉素敏感。毒力基因聚合酶链反应检测结果显示，所有菌株均携带毒力表达调控基因（toxR）和溶血素基因（hlyA），未检出霍乱肠毒素基因（ctxA）、毒力协同调节菌毛基因（tcpA）和肠毒素基因（ST）；5株病例分离株和1株冷柜内壁分离株经限制性内切酶NotⅠ消化后的PFGE图谱为同一型别。结论 此次食物中毒的病原体为非O1/O139群霍乱弧菌，具有共同的遗传特征，菌株出现了多重耐药，提示应加强该类菌株的监测，防止大范围扩散或暴发流行。

Etiological characteristics of Vibrio cholerae non-O1/O139 strains isolated from a food poisoning in Guangdong

Objective To investigate the drug resistance and molecular characteristics of Vibrio cholera non-Ol/O139 strains isolated from a food poisoning in a factory in Guangzhou,Guangdong province in 2014.Methods Biochemical identification,serological identification,drug susceptibility test,virulence-associated gene detection and PFGE molecular typing on six V.choleraenon-O1/O139 strains isolated from a food poisoning in Guangzhou were conducted.Results The biochemical identification and serological identification results indicated that the six strains were all V.cholera non-O1/O139 strains;the drug susceptibility analysis showed that the 6 strains were resistant to ampicillin,cefixime,cefradine,amikacin,tobramycin,gentarnycin and polymyxin B,but sensitive to norfloxacin,ciprofloxacin,cotrimoxazole,furazolidone,tetracycline,pipemidic acid,erythromycin and chloramphenicol;The PCR detection of virulence gene showed that all the strains were positive for toxR and hlyA genes,but negative for ctxA,tcpA and ST genes;and the PFGE molecular typing of the strains digested by Not Ⅰ showed that five strains isolated from the cases and one strain isolated from the inner wall of a refrigerator were in the same type.Conclusion The pathogen of this food poisoning was V.cholera non-O1/O139,which shared common genetic characteristics;and the strains were multi drug resistant.It is suggested to guide the clinical medication based on drug susceptibility test results to reduce the drug resistant strains.