牛源MRSA新疆流行株的分离鉴定及spa基因多态性分型

【目的】明确新疆地区牛源耐甲氧西林金黄色葡萄球菌(MRSA)流行株的流行特点,为有效防控新疆奶牛乳房炎和子宫内膜炎提供参考依据。【方法】采用分离培养、生化鉴定、药敏试验等方法对牛源MRSA进行鉴定,并以PCR扩增牛源MRSA新疆流行株spa基因的X区,测序结果列提交至spa分型数据库(http://www.ridom.de/spaserver/)进行spa基因多态性分型。【结果】从221份样品中共检测出71株金黄色葡萄球菌,其中对苯唑西林抑菌直径小于10mm的有8株;而以mec A引物进行PCR扩增,发现扩增结果呈阳性的有13株,MRSA检出率为18.3%。spa基因分型有4种,分别为t779、t2883、t13751和t1939,其中5株为t779(r08),4株为t2883(r07-r23-r21-r17-r34),2株为t13751(r07-r23-r12-r21-r17-r12),2株为t1939(r07-r23-r02-r34),即t779(r08)为MRSA新疆流行株的主要spa基因分型。【结论】MRSA在新疆不同地区均有分布,且其耐药情况不断变化,以t779(r08)为MRSA新疆流行株的主要spa基因分型。

Identification of MRSA isolated from bovine epidemic in Xinjiang and spa polymorphism genotyping

Objective]The aime of the study was to study epidemiological characteristics of methicillin-resistant Staphylococcus aureus(MRSA)isolated from bovine in Xinjiang,and provide reference basis for effective prevention and control of dairy cows mastitis and endometritis in Xinjiang.Method]Differential culture,biochemical identification and drug sensitive test were applied to identify MRSA,and X region of spa gene from MRSA epidemic isolate in Xinjiang was amplified. The sequencing results were submitted to spa genotype database(http://www.ridom.de/spaserver/)for spa polymorphism genotyping.Result]Seventy-one S. aureus isolates were selected from two hundred and twenty-one sam-ples. Among them,bacteriostatic diameter of eight strains for oxacillin was less than 10 mm. PCR amplification was con-ducted with mecA primer,13 strains were positive,the detection rate of MRSA were 18.3%. Four spa genotypes were de-tected:t779,t2883,t13751 and t1939. Five strains were t779(r08),four strains were t2883(r07-r23-r21-r17-r34),two strains were t13751(r07-r23-r12-r21-r17-r12)and two strains were t1939(r07-r23-r02-r34). In another word,t779(r08) was the predominant spa genotype among MRSA epidemic isolates in Xinjiang.Conclusion]MRSA is distributed in different regions of Xinjiang,and its drug resistance changes constantly. t779(r08) is the predominant spa genotype among MRSA epidemic isolates in Xinjinag.