上海地区市售生鲜肉中单核细胞增生李斯特菌和沙门氏菌的污染监测分析

Monitoring results of Listeria monocytogenes and Salmonella in fresh meat samples at retail in Shanghai city

目的调查上海地区市售生鲜肉中单核细胞增生李斯特菌和沙门氏菌的污染情况。方法 2018年7月~2019年4月,从上海市88家农贸市场和42家超市抽样308件,其中鲜猪肉114件、整鸡92件、鲜牛肉102件。按食品安全国家标准分别进行单核细胞增生李斯特菌和沙门氏菌的检测,采用VITEK2全自动生化鉴定仪对疑似菌株进行鉴定确认,并对沙门氏菌分离株进行血清分型。结果生鲜肉中单核细胞增生李斯特菌和沙门氏菌的检出率为分别为28.2%和39.6%,其中鲜牛肉(48.0%)中单核细胞增生李斯特菌的检出率显著高于猪肉(17.5%)和整鸡(19.6%)(P<0.001),而猪肉(46.5%)和整鸡中(59.8%)沙门氏菌的检出率则显著高于牛肉(13.7%)(P<0.001);农贸市场采集的鲜肉样品中单核细胞增生李斯特菌(P=0.008)和沙门氏菌(P<0.001)的污染率均显著高于超市;血清学实验结果显示122株沙门氏菌分布于21种不同血清型,其中Corvallis血清型(14.75%)流行率最高。结论上海地区市售生鲜肉中存在较高的单核细胞增生李斯特菌和沙门氏菌的污染率,极易引发食源性疾病,建议政府监管部门加强对生鲜肉食品的监管。

Objective To investigate the contamination of Listeria monocytogenes and Salmonella in fresh meat samples at retail in Shanghai City. Methods From July 2018 to April 2019,308 samples,including 114 fresh pork,92 whole chickens,and 102 fresh beef,were sampled from 88 traditional markets and 42 supermarkets. Then,all samples were tested for Listeria monocytogenes and Salmonella according to national standard methods. All suspected isolates were further confirmed by the VITEK2 automatic biochemical identification method and all Salmonella isolates were serotyped. Results The detection rates of Listeria monocytogenes and Salmonella in fresh meat samples were 28.2% and 39.6%,respectively. Furthermore,the detection rate of Listeria monocytogenes in beef(48.0%) samples was significantly higher than that of pork(17.5%) and whole chicken samples(19.6%)(P<0.001),while the detection rate of Salmonella in pork(46.5%) and whole chicken(59.8%) was significantly higher than beef samples(13.7%)(P<0.001). The contamination rates of Listeria monocytogenes(P=0.008) and Salmonella(P<0.001) in traditional markets were significantly higher than those in supermarkets;122 Salmonella strains were distributed in 21 different serotypes,of which Corvallis serotype(14.75%) had the highest prevalence rate. Conclusion There is a high level of contamination of Listeria monocytogenes and Salmonella in fresh meat foods in Shanghai,which can easily lead to food-borne diseases. Thus,it is recommended that government regulatory authorities should strengthen the supervision of fresh meat foods.