生食蔬菜源金黄色葡萄球菌毒素编码基因和药敏性分析  

Toxin-Encoding Genes and Drug Susceptibility of Staphylococcus aureus from Vegetables Consumed Raw

作　　者：白小宝 索佳 曹晨阳[1] 苏丽 赵越凡 刘丽莎 冯承谦 吕欣[1] 杨保伟[1] BAI Xiaobao;SUO Jia;CAO Chenyang;SU Li;ZHAO Yuefan;LIU Lisha;FENG Chengqian;LÜXin;YANG Baowei(College of Food Science and Engineering,Northwest A&F University,Yangling 712100,China;China National Center for Food Safety Risk Assessment,Beijing 100022,China;Hanzhong City Hantai District Market Supervision Administration Cross Street Vegetable Wholesale Market Supervision Office,Hanzhong 723000,China)

机构地区：[1]西北农林科技大学食品科学与工程学院,陕西杨凌712100 [2]国家食品安全风险评估中心,北京100022 [3]汉中市汉台区市场监督管理局过街楼蔬菜批发市场监管所,陕西汉中723000

出　　处：《食品科学》2023年第14期94-99,共6页Food Science

基　　金：“十三五”国家重点研发计划重点专项(2017YFC1601400)。

摘　　要：目的:探究零售生食蔬菜中金黄色葡萄球菌分离株携带的毒素基因和药敏性。方法:使用聚合酶链式反应扩增nuc基因,对分离于陕西西安、宝鸡、汉中和延安等地大型超市、农贸市场和摊贩售卖的西红柿、生菜、菠菜和包菜的27株金黄色葡萄球菌进行鉴定,检测19种毒素基因和12种耐药基因在其中的流行情况;使用琼脂稀释法测定其对14种抗生素的药敏性。结果:共检出17株甲氧西林敏感金黄色葡萄球菌和10株苯唑西林敏感耐甲氧西林金黄色葡萄球菌(oxacillin-susceptible methicillin-resistant Staphylococcus aureus,OS-MRSA)。共检出8种毒素编码基因,其中sec检出率最高(29.6%,8/27)。51.9%(14/27)的菌株至少携带1种毒素编码基因,共检出9种毒素编码基因谱。共检出blaZ、mecA、ermC、tetK、dfrG、dfrK、aac(6′)/aph(2″)7种耐药基因。菌株对苯唑西林、利福平和万古霉素全部敏感,对阿莫西林/克拉维酸耐药最为普遍,其次分别对甲氧苄啶/磺胺甲恶唑、氨苄西林、红霉素、头孢西丁、环丙沙星、头孢曲松、庆大霉素、阿米卡星、四环素和氯霉素耐药。88.9%(24/27)的菌株对3种及以上抗生素耐药。结论:陕西省生食蔬菜中存在OS-MRSA菌株,具有多重耐药性,携带多种毒素编码基因,对食品安全具有潜在危害。Objective:To investigate the toxin-encoding genes and antibiotic susceptibility of Staphylococcus aureus isolates from retail vegetables consumed raw.Methods:The 27 S.aureus isolates from tomato,lettuce,spinach and cabbage collected from supermarkets,farmers’markets and vendors in Xi’an,Baoji,Hanzhong and Yan’an of Shaanxi province were identified by PCR amplification of the nuc gene,the prevalence of 19 toxin-encoding genes and 12 antibiotic resistance encoding genes in these isolates was evaluated,and the antibiotic susceptibility to 14 antibiotics was determined by the agar dilution method.Results:Seventeen of these isolates were identified as methicillin-susceptible S.aureus(MSSA)and the remaining 10 isolates were identified as oxacillin-susceptible methicillin-resistant S.aureus(OS-MRSA).A total of eight toxin-encoding genes were detected in the 27 isolates,and the detection rate(29.6%,8/27)of sec was highest.In addition,51.9%(14/27)of these isolates carried at least one toxin-encoding gene,and nine toxin-encoding gene profiles were totally identified.Seven antibiotic resistance genes including blaZ,mecA,ermC,tetK,dfrG,dfrK,and aac(6′)/aph(2″)were detected.The isolates were all susceptible to oxacillin,rifampicin and vancomycin.Resistance to amoxicillin/clavulanate was most commonly detected,followed by trimethoprim/sulfamethoxazole,ampicillin,erythromycin,cefoxitin,ciprofloxacin,ceftriaxone,gentamicin,amikacin,tetracycline and chloramphenicol.Twenty-four(88.9%)isolates were resistant to three or more antibiotics.Conclusion:OS-MRSA is prevalent in vegetables consumed raw in Shaanxi province,and it has multiple antibiotic resistances and carries multiple toxin-encoding gens,posing a potential food safety hazard.

关 键 词：生食蔬菜 金黄色葡萄球菌 毒素编码基因 药敏性 

分 类 号：TS201.6[轻工技术与工程—食品科学]