生鲜乳金黄色葡萄球菌污染来源调查及其耐药性

Investigation of Pollution Sources and Resistance Assay of Staphylococcus aureus in Raw Fresh Milk

为考察贵阳市生鲜乳中金黄色葡萄球菌污染环节及其对药物的敏感性,采集贵阳市周边5个大型奶牛场及一个牛奶加工厂的乳区棉签拭子75份和各生产环节奶样310份,按国家标准(GB 4789.10—2010)分离鉴定金黄色葡萄球菌,并测定其对9种常用抗菌药物的敏感性。结果表明:生鲜乳中金黄色葡萄球菌污染主要来源于牛乳头内;传统的"弃前三把奶"工艺对降低生鲜乳中金黄色葡萄球菌污染的作用不明显;规范的乳区消毒可以有效地降低乳头外环境金黄色葡萄球菌对生鲜乳安全的影响;所调查奶牛场的金黄色葡萄球菌对磺胺类、β-内酰胺类和四环素类药物的耐药水平较高。

In order to investigate the pollution sources of Staphylococcus aureus （S.saureus） in raw fresh milk and determine the resistance of S.saureus, 88 strains S.saureus were isolated with the national standard method （GB4789.10--2010）from 310 milk samlpes and 75 udder region swabs, which collected from 5 large-scale dairy farms and a dairy plant in Guiyang city. The antibiotic susceptibilities of 88 strains S.saureus to 9 common antibiotics were tested with the method of micro-broth dilution according to the standard of CLSI （2009）. The results showed that the S.saureus growing inside udder was the main pollution sources of S.saureus contaminating raw fresh milk. The effect of traditional process, which discarded milking of initial three hands, to reduce the pollution of S.saureus in the raw milk was not obvious. The way of specification disinfection on udder region could diminish the risk of S. saureus contamination to raw fresh milk. The resistances of isolated S.saureus to sulfa, beta lactam and tetracycline were high.