一起由两种型别沙门菌混合感染引起暴发疫情的病原特征

目的对一起由科瓦利斯沙门菌和鼠伤寒沙门菌混合感染引起的食源性暴发的病原体进行耐药分析和分子分型。方法参照GB4789.4-2010标准对可疑菌落进行生化鉴定、血清学分型及药敏试验后,进行脉冲场凝胶电泳(PFGE)分子分型。结果从两份暴发病例粪便样品中同时检出科瓦利斯沙门菌(8,20∶z4,z23∶–)2株和鼠伤寒沙门菌(4,5,12∶i∶1,2)2株。选择13种常用的抗生素进行药敏试验,4株沙门菌均对阿米卡星和庆大霉素耐药,其中2株科瓦利斯沙门菌还同时表现出对莫西沙星和四环素耐药。2株科瓦利斯沙门菌和2株鼠伤寒沙门菌的PFGE指纹图谱分别完全一致。结论这是一起由科瓦利斯沙门菌和鼠伤寒沙门菌混合感染所致的食源性暴发,PFGE分子分型可有效应用于食物中毒的溯源分析。

Pathogenic characteristics of a foodborne outbreak caused by mixed infection of two types of Salmonella

Objective To analyze the antibipotic resistance and molecular typing of the Salmonella corvallis and Salmonella typhimurium trains caused a foodborne outbreak. Methods We firstly performed the conventional identification and sero-typing according to the guide of the GB4789.4-2010,and then conducted further analysis of the antibiotic resistance and pulsed-field gel electrophoresis (PFGE) molecular typing of the strains. Results Two strains of Salmonella corvallis（8,20∶z4,z23∶-） and two strains of Salmonella typhimurium（4,5,12∶i∶1,2） were detected simultaneously from two fecal samples. The results of antibiotic resistance test indicated that the four strains of Salmonella resistance to Amikacin and Gentamicin, which was selected from 13 kinds of commonly used antibiotics, while two strains of Salmonella corvallis showed resistance to Moxifloxacin and Tetracycline. The PFGE analysis revealed that two Salmonella corvallis strains shared the same PFGE pattern, and the Salmonella typhimurium strains shared the same PFGE pattern, too. Conclusion This food borne outbreak is caused simultaneously by two different serotypes strains of the Salmonella corvallis and Salmonella typhimurium. The PFGE molecular sub typing can be effectively used on the source tracing in foodborne outbreak investigation.