鄂西北地区食源性金黄色葡萄球菌污染及耐药性和毒力基因分析

目的 了解鄂西北地区食源性金黄色葡萄球菌的检出情况、耐药性以及毒力基因分布特征。方法 从湖北省襄阳市、十堰市、随州市三地共采集303份食物样品进行金黄色葡萄球菌筛查,通过聚合酶链式反应(PCR)法进行耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)的鉴定和毒力基因检测,并用K-B纸片扩散法进行耐药性测定。结果 303份样品中共有41份检出金黄色葡萄球菌,阳性率为13.53%,其中生肉制品检出率最高(23.91%,22/92)。在产肠毒素菌株中以携带产肠毒素基因sea的菌株最多,占87.80%(36/41)。携带表皮剥脱素基因eta和中毒性休克综合征毒素基因tst的菌株分别占97.56%(40/41)和7.32%(3/41)。同时携带3种及以上肠毒素基因的菌株占17.07%(7/41)。同时含有eta和tst的菌株占2.44%(1/41)。药敏结果显示,分离菌株对青霉素、四环素、红霉素和多西环素的耐药率分别为78.05%(32/41)、43.90%(18/41)、31.71%(13/41)和21.95%(9/41),对其他8种抗菌药物的耐药率均<20%。mecA基因检测表明,19.51%(8/41)的菌株为MRSA,且7株MRSA菌株来源于生肉制品和未加调料的素卤菜。结论 鄂西北地区食源性金黄色葡萄球菌具有较高的检出率,而且产毒株较多,并且存在多重耐药现象,相关部门需加强食品安全监测以控制该菌株的流行与扩散。

Analysis of resistance and virulence genes of foodborne Staphylococcus aureus in northwestern Hubei Province

Objective To understand the prevalence, drug resistance, and virulence gene distribution of foodborne Staphylococcus aureus in northwestern Hubei Province. Methods A total of 303 food samples were collected from Xiangyang City, Shiyan City, and Suizhou City of Hubei Province for Staphylococcus aureus screening. Toxic genes and methicillin-resistant Staphylococcus aureus(MRSA)were detected with PCR method. The drug resistance of Staphylococcus aureus was determined with K-B paper diffusion method. Results Staphylococcus aureus strain was determined from 41 samples with the positive rate of 13.53%. Among them, the highest detection rate was from raw meat products (23.91%, 22/92). Among the enterotoxigenic strains, the strain carrying sea was the most common, accounting for 87.80% (36/41). The strains carrying eta and tst accounted for 97.56% (40/41) and 7.32% (3/41), respectively. Strains carrying three or more enterotoxin genes accounted for 17.07% (7/41). 2.44% (1/41) of strains carry eta and tst simultaneously. The drug susceptibility result showed that the penicillin, tetracycline, erythromycin, and doxycycline accounted for 78.05%(32/41), 43.90%(18/41), 31.71%(13/41)and 21.95%(9/41)respectively. The mecA gene test showed that 19.51% (8/41) of the strains were MRSA strains. Conclusion Foodborne Staphylococcus aureus in northwestern Hubei Province had a higher detection rate, toxic gene carring rate, and multiple drug resistance. Related departments need to strengthen food safety monitoring to control the spread of the strain.