生鲜牛奶中金黄色葡萄球菌的分离及耐药性分析

目的 通过对山东、湖南等5省生鲜牛奶中的金黄色葡萄球菌进行耐药表型和耐药基因分析,了解我国生鲜牛奶中金黄色葡萄球菌的污染状况和耐药情况。方法 对采集的600份生鲜牛奶中分离的金黄色葡萄球菌进行MIC测定,并对9种耐药基因进行检测,对耐药表型和耐药基因携带状况进行分析。结果 生鲜牛奶中金黄色葡萄球菌分离率为26.17%;所有分离菌株对恩诺沙星和万古霉素敏感,对青霉素耐药,98.73%的分离菌株对阿莫西林耐药,大多数分离菌携带多种耐药基因。结论 分离的157株菌中有29株MRSA,其中有22株携带femA基因,应加强牛奶中耐药菌株的监测,为指导奶牛场安全合理用药和保障消费者食品安全提供依据。

Isolation of Staphylococcus aureus from raw milk and its drug resistance analysis

To understand the status of contamination and antimicrobial resistance of Staphylococcus aureus (S. aureus) isolated from raw cow milk, 600 samples were collected from five different provinces in China. After isolation and identification of S. aureus from these samples, 157 S. aureus isolates were obtained. Furthermore, their resistant phenotype and resistant gene were analyzed by MIC detection, as well as nine drug-resistance genes determination and analysis. The result revealed that most of the S. aureus isolates contained multiple antibiotic resistant genes, and all of the isolates were resistant to penicillin. Of 98.73% isolates were resistant to amoxicillin. Conversely, all of the isolates were sensitive to enrofloxacin and vancomycin. Moreover, there were 29 MRSA positive strains among which 22 strains carrying femA gene. In conclusion, much more attention should be paid to the drug-resistance capabilities of field S. aureus isolates in raw cow milk, and further monitoring of drug resistant S. aureus strains in milk should also be strengthened so as to ensure milk safety.