食品中金黄色葡萄球菌致病性研究进展

目的了解市售生鲜肉中金黄色葡萄球菌的污染、群体遗传多样性和毒素基因携带规律，为金黄色葡萄球菌的污染防控提供依据。方法按照GB4789.10—2016对金黄色葡萄球菌进行分离鉴定，采用多位点序列分型方法(MLST)进行分子分型，利用PCR方法检测11种毒素基因的携带情况。结果148份样品中有56份检出金黄色葡萄球菌，污染率为30.1%，分离到56株菌。56株菌可分成11种序列型(STs)，其中ST7(28.6%)是主要流行的序列型，其他优势序列型分别为ST188(23.2%)，ST1(8.93%)和ST88(8.93%)。6种毒素基因在27株菌(48.2%)中检出阳性结果，其中杀白细胞素基因pvl(26.8%)检出率最高，其次为肠毒素基因sec(12.5%)，seh(10.7%)，sea(7.1%)和sed(5.4%)。结论金黄色葡萄球菌在市售生鲜肉中具有较高的污染率，丰富的遗传多样性表明菌株污染来源广泛，与食物中毒和临床感染相关的毒素基因具有较高的分布比例，应加强对生鲜食品中金黄色葡萄球菌的监控。

Transmission and persistence of livestock-associated methicillin-resistant Staphylococcus aureus among veterinarians and their household members

ObjectiveTo investigate the contamination situation, molecular diversity and virulence gene distribution of Staphylococcus aureus isolated from market fresh meat, providing basis for its prevention and control.MethodsS.aureus strains were isolated and identified according to GB 4789.10—2016.MLST(multilocus sequence typing) method was used for genotyping these isolates, and the distribution of 11 toxin genes were tested by PCR.ResultsA total of 56 S.aureus-positive samples (30.1%) were found out of 148 samples from market fresh meat, and finally 56 strains were isolated.MLST results showed that these strains could be typed into 11 different sequence types (STs).Among them ST7 (28.6%) was dominant, and followed by ST188 (23.2%), ST1 (8.93%) and ST88 (8.93%).Six toxin genes were detected in 27 strains (48.2%), in which the most frequent toxin gene was pvl gene (26.8%), followed by enterotoxin genes sec (12.5%), seh (10.7%), sea (7.1%) and sed (5.4%).ConclusionS.aureus has a high pollution rate in raw meat commodities.The high genetic diversity of the strains implies multiple sources of contamination.The toxin genes associated with food poisoning and clinical infection show a high distribution proportion.The monitoring of S.aureus in market fresh meat should be strengthened.