太原市零售肉制品中食源性致病菌的污染现状和菌型特征

Contamination status and characteristics of food-borne pathogenic bacteria in retail meat products in Taiyuan

目的调查山西太原地区流通零售肉制品中沙门氏菌、副溶血性弧菌和金黄色葡萄球菌污染现状和菌型耐药等表型特征.方法2017年腹泻病流行季节从太原市辖10个县(区)的农贸市场、超市,随机采集禽畜肉制品,增菌后分离沙门氏菌、副溶血性弧菌和金黄色葡萄球菌.对沙门氏菌进行血清分型,对金黄色葡萄球菌使用固相酶联标记方法(ELISA)检测肠毒素(A^E),对副溶血性弧菌检测直接溶血素(tdh)和间接溶血素(trh)毒力基因;对3种食源性致病菌使用微量稀释法进行抗生素耐药检测.结果在采集的123份禽、畜肉制品中共分离3种食源性致病菌38株(检出率为30.9%),其中沙门氏菌为优势污染菌(26株,21.1%),其次为副溶血性弧菌(8株,6.5%)和金黄色葡萄球菌(4株,3.3%).26株沙门氏菌分属10个血清型,其中分离自猪肉的沙门氏菌血清型存在多样性且优势血清型德比沙门氏菌、黄金海岸和利物浦沙门氏菌系本地首次在生猪肉和熟肉制品中分离;分离自鸡肉的沙门氏菌血清型呈单一性,为肠炎沙门氏菌.4株金黄色葡萄球菌均分离自生畜肉且肠毒素型为3株E型和1株复合型(A/E).8株副溶血性弧菌为tdh、trh均阴性的非流行株.沙门氏菌的多重耐药(MDR)特征以对氨苄西林-氯霉素-链霉素-磺胺异噁唑-四环素耐药型(ACSSuT)较多,对氟喹诺酮和头孢类药物敏感度高;金黄色葡萄球菌75%为MDR;副溶血性弧菌未发现耐三代头孢菌素和氟喹诺酮类抗生素菌株以及MDR.结论太原地区流通的生、熟肉制品中存在食源性多病原菌污染,沙门氏菌型多样且MDR比例高.建议监管部门加强养殖业抗生素使用管理和基于专业实验室的肉制品供应链监测.

Objective To investigate the contamination status of Salmonella,Vibrio parahaemo-lyticus and Staphylococcus aureus and bacterial resistance in retail meat products in Taiyuan,Shanxi Prov-ince.Methods In the epidemic season of diarrhea in 2017,poultry and meat product specimens were ran-domly collected from the farmer's markets and supermarkets of 10 districts and counties of Taiyuan.Salmo-nella,Vibrio parahaemolyticus and Staphylococcus aureus were isolated form these specimens.Serotypes of Salmonella strains were analyzed.ELSIA was used to detect Staphylococcus aureus enterotoxin(A-E).Vibrio parahaemolyticus isolates were tested for the virulence genes encoding direct hemolysin(tdh)and indirect hemolysin(trh).Antibiotic resistance of the three food-borne pathogens were analyzed using microdilution methods.Results A total of 38 food-borne pathogens were isolated from 123 poultry and livestock meat product specimens with a positive rate of 30.9%,of which mainly were Salmonella(26 strains,21.1%),followed by Vibrio parahaemolyticus(8 strains,6.5%)and Staphylococcus aureus(4 strains,3.3%).The 26 strains of Salmonella belonged to 10 serotypes.The Salmonella strains isolated from pork specimens had diverse serotypes.Salmonella serovar Derby,Salmonella serovar Gold-coast and Salmonella serovar Liver-pool were isolated from raw and cooked pork food for the first time in Taiyuan.All Salmonella strains isolated form chicken products were Salmonella enteritis.The enterotoxin types of the four Staphylococcus aureus strains were three E-type and one complex type(A/E).All Vibrio parahaemolyticus isolates were negative for tdh or trh gene.Ampicillin,chloramphenicol,streptomycin,sulphonamides and tetracyclines(ACSSuT)resistance was prevalent in multi-drug resistant(MDR)Salmonella strains,but there was high sensitivity to fluoroquinolones and cephalosporins.MDR Staphylococcus aureus accounted for 75%.No third-generation cephalosporin-or fluoroquinolone-resistant or MDR Vibrio parahaemolyticus strains were isolated.Conclu-sions There were food-borne multi-pathogenic bacteria contamination in retail raw and cooked meat prod-ucts in Taiyuan.Salmonella strains had diverse serotypes and high MDR rate.It was suggested that the regu-latory authorities should strengthen the management of antibiotic use in aquaculture and specialized laborato-ry-based monitoring of meat supply chain.