奶牛源MRSA流行株的耐药特性SCCmecA分型研究

ANTIBIOTIC RESISTANCE AND SCCMECA GENOTYPING OF MRSA STRAINS FROM COW MASTITIS CASES

为了了解引起奶牛乳房炎的金黄色葡萄球菌分离株的耐药性及其分子流行病学特征,本研究采用纸片扩散法检测临床分离的71株金黄色葡萄球菌的耐药特性,并对耐甲氧西林金黄色葡萄球菌(Methicillin-resistant staphylococcus aureus,MRSA)进行判定;应用多重PCR方法对MRSA进行SCCmec分型。结果显示:在新疆地区71株金黄色葡萄球菌临床分离株中共检出13株MRSA,检出率为18.3%;金黄色葡萄球菌对呋喃妥因、利福平100%敏感,MRSA对头孢类、氟喹诺酮类和大环内酯类抗菌药物的耐药率明显高于甲氧西林敏感金黄色葡萄球菌(methicillin sensitive staphylococcus aureus,MSSA);MRSA的SCCmec基因型共以SCCmecⅠ和SCCmecⅣa型为主,均占76.9%,另外,1株MRSA仅有1种SCCmecⅢ型,1株MRSA有SCCmecⅠ、SCCmecⅢ和SCCmecⅣa型。本研究结果表明,MRSA耐药性多样,新疆地区MRSA主要流行株为SCCmecⅠ和SCCmecⅣa型。

In order to understand antimicrobial resistant and epidemiological characteristics of Staphylococcus aureus（S.aureus） from cow mastitis, 71 clinical Staphylococcus aureus isolates were indentified and examined for their drug resistance using disk diffusion method in the present study. SCCmec genotyping was conducted using multiplex PCR method. The results show that a total of 13 methicillinresistant Staphylococcus aureus（MRSA） isolates were identified. These S. aureus isolates were 100% susceptible to Furadantin and Rifampicin. Drug resistance of MRSA isolates was significantly higher than that of methicillin-sensitive Staphylococcus aureus（MSSA） regarding cephalosporins, quinolones and macrolides tested. The SCCmecⅠand SCCmecⅣa were the predominant genotypes in the MRSA, both accounting for 76.9%. One isolate only showed SCCmecⅢ type and another isolate showed three types with SCCmecⅠ, SCCmecⅢ and SCCmecⅣa. In conclusion, that these MRSA isolates showed multiple resistance, and SCCmecⅠand SCCmecⅣa were the predominant genotypes.