育肥前期和育肥后期肉猪携带金黄色葡萄球菌监测分析研究

Monitoring and analysis of Staphylococcus aureus in the early stage and later stage of fattening pig

目的了解育肥前期和育肥后期肉猪及其养殖场环境和养殖人员携带金黄色葡萄球菌耐药、分子分型特点,为预防和控制相关疾病提供科学依据。方法在成都某养猪场对同一群肉猪的育肥前期和育肥后期2次进行采样,进行金黄色葡萄球菌分离鉴定,对分离株使用肉汤稀释法进行药物敏感性试验;以SPA和PFGE法进行分子分型研究。结果共采集样本150份,共分离35株金黄色葡萄球菌;35株分离株均为MRSA株,均含有mec A基因。主要耐药谱为OXA-ERY-CIP-SXT-CLI-CHL-TET和OXA-ERY-CIP-CLI-CHL-TET。所有分离株SPA型别均为t899型;PFGE分析显示,该猪场MRSA分离株存在2个明显的优势PFGE型。结论肉猪及其养殖场金黄色葡萄球菌分离率高,耐药严重,肉猪、养殖环境和养殖人员有相互交叉污染和感染的可能性,为确保人员健康及肉猪屠宰后猪肉质量,应进一步加强对养殖过程的监测。

Objective To know the antimicrobial resistance and the molecular characteristic of Staphylococcus aureus in breeding environments,breeders and the early stage and later stage of fattening pigs,so as to provide scientific basis for the prevention and control of related diseases. Methods Samples were collected from the same group of fatting pigs respectively at the early stage and at the later stage from a swine farm in Chengdu. And then Staphylococcus aureus were isolated from samples. The drug sensitivity test was carried out for the isolated strains using broth dilution method. Molecular typing was studied by SPA and pulsed field gel electrophoresis（PFGE）. Results A total of 150 samples were collected,35 strains of Staphylococcus aureus were isolated,which were all MRSA strains and contained mec A genes. Two predominant antimicrobial resistant profiles were OXA-ERY-CIP-SXT-CLI-CHL-TET and OXA-ERY-CIP-CLI-CHL-TET. All SPA isolates type were t899. PFGE analysis showed that two dominant PFGE clusters were identified. Conclusion The pigs and the farms have a high isolate rate of Staphylococcus aureus. Pigs,breeding environments and breeders have the possibility of cross-contamination and infection. In order to ensure the quality of pig meat after slaughtering,we should further strengthen the monitoring of the breeding process.