2018年浙江省余姚市一起伊桑吉沙门菌引起的食源性疾病暴发事件调查

An outbreak of foodborne disease caused by Salmonella Isangi in Yuyao,Zhejiang,2018

目的研究2018年浙江省余姚市发生的一起因食用被伊桑吉沙门菌污染的烤鸭引起的食源性疾病暴发事件,了解病原的生物学特性、分子分型及药敏特征。方法使用国家标准对可疑食品样本进行致病菌检测,对收集的沙门菌进行系统生化和血清型鉴定,利用纸片扩散法进行药敏试验,采用脉冲场凝胶电泳(PFGE)和全基因组测序(WGS)方法进行分子分型分析,通过查阅患者就诊记录和回访进行流行病学、临床和实验室调查。结果经流行病学调查和实验室检测确认为一起因食用被伊桑吉沙门菌污染的烤鸭引起的食源性疾病暴发事件,共分离到3株伊桑吉沙门菌,均为单耐药株(耐复方新诺明)。3株菌PFGE带型完全一致,均为ST216型,全基因组多位点序列分型(wgMLST)分析发现2株患者分离株存在1个差异等位基因,但均携带126种已知毒力基因和1个氨基糖苷类耐药基因aac(6)-Iaa。结论此次事件为一起因食用被ST216型伊桑吉沙门菌污染的烤鸭引起的食源性疾病暴发事件,为余姚市首次报道。

Objective To investigate an outbreak of foodborne disease caused by Salmonella Isangi in Yuyao,Zhejiang province,in 2018,and analyze the biological and epidemiological characteristics,molecular typing and drug sensitivity characteristics of isolated pathogens.Methods Pathogenic bacteria were detected according to national standard in suspicious food samples.Salmonella was identified by systematic biochemical and serum typing methods.Drug sensitivity test was carried out with disk diffusion method.Pulse-field gel electrophoresis(PFGE)and whole genome sequencing(WGS)were used for molecular typing analysis.The patients’medical record analysis and follow-up were conducted in the epidemiological investigation.Results Three strains of Salmonella Isangi were isolated from 1 food sample(roast duck)and 2 patient stool samples.The isolates were resistant only to cotrimoxazole.PFGE band pattern was completely consistent.Multilocus sequence typing(MLST)showed that the strains belonged to ST216.wgMLST analysis showed that there was an allelic difference between two isolates from the patients.Furthermore,all of them carried 126 known virulence genes and a aminoglycoside antibiotic resistance gene aac(6)-Iaa.Conclusion It is confirmed that the outbreak of foodborne disease was caused by the consumption of roast duck contaminated by Salmonella Isangi ST216,which was first reported in Yuyao.