养殖源耐甲氧西林金黄色葡萄球菌的SCCmec耐药元件、毒力危害和流行性分析

金黄色葡萄球菌(Staphylococcus aureus)是一种常见的人兽共患病病原菌,其分泌的外毒素如溶血素、杀白细胞素、脱皮毒素、肠毒素等可引发人或养殖动物多种疾病。耐甲氧西林金黄色葡萄球菌(Methicillin-resistant Staphylococcus aureus, MRSA)是携带含mec基因簇的葡萄球菌盒氏染色体(Staphylococcal chromosome cassette mec, SCCmec)遗传元件的多重耐药菌。SCCmec对MRSA的多重耐药性起重要作用。SCCmec元件中mecA基因介导了MRSA对β-内酰胺类药物的耐药性,而SCCmec元件的可变区插入的耐药基因对MRSA的多重耐药性具有重要作用。近年来,欧洲、北美等国家陆续报道在养殖业环境及动物中检测到多重耐药的养殖源MRSA(Livestock-associated MRSA,LA-MRSA),且LA-MRSA可以通过养殖环境等途径传播到人,对人的健康和公共卫生安全构成潜在威胁。本文综述了S. aureus的耐药性变化、MRSA的SCCmec耐药元件和SCCmec型别变迁以及LA-MRSA的毒力危害和流行状况,对了解S. aureus耐药性和SCCmec分型以及控制和预防LA-MRSA在人兽间传播、感染具有一定的指导意义。

SCCmec resistant mechanism,toxicity and prevalence in livestock-associate methicillin-resistant Staphylococcus aureus

Staphylococcus aureus is one of the most frequently encountered zoonotic pathogens. This bacterium produces the notable virulence factors such as hemolysin, panton-valentine leucocidin, exfoliative toxins and enterotoxin, which can cause invasive disease in humans and animals. Methicillin-resistant S. aureus(MRSA) is a multidrug-resistant bacterium which acquired the staphylococcal chromosome cassette mec (SCCmec). SCCmec is one of the key reasons for the antibiotic resistance of MRSA. As for MRSA resistance, the β-lactam resistance is mediated by mecA gene, and the drug-resistance genes inserted in the variable area of the SCCmec element play an important role in the multidrug resistance of MRSA. In recent years, it has been reported in Europe, North America and other countries that the multidrug resistance MRSA was detected in aquaculture environment and livestock. Besides, MRSA poses a serious threat to public health, and it can colonize and cause invasive disease in humans through aquaculture environment or other ways. This review summarizes drug resistance change of S. aureus and analysis of SCCmec resistance elements, toxicity and prevalence of livestock-associate MRSA, which would have theoretical and practical significance to understand S. aureus drug resistance, SCCmec typing, as well as control and prevent LA-MRSA transmission and infection between animals and humans.