奶牛乳房炎金黄色葡萄球菌的分离鉴定及药敏试验

Isolation,Identification and Antimicrobial Sensitivity Test of Staphylococcus aureus from Dairy Cow Mastitis

[目的]了解泰州市某奶牛场乳房炎中金黄色葡萄球菌(Staphylococcus aureus)感染情况及其对常用药物的敏感性。[方法]试验选用Baird-Parker培养基分离、生化鉴定、PCR检测等方法,对采集的9份奶牛乳房炎奶样进行分离鉴定和药敏试验。[结果]共分离到6株葡萄球菌,进一步通过凝固酶试验和16S rDNA测序等方法鉴定其中3株为金黄色葡萄球菌。药敏试验结果显示,3株金黄色葡萄球菌对青霉素G均耐药,2株对四环素耐药,2株对红霉素和苯唑西林表现为中介。[结论]该次分离的金黄色葡萄球菌主要对青霉素G和四环素耐药,对其他常用抗生素表现为敏感。

[Objective]To investigate the prevalence of Staphylococcus aureus associated with mastitis and its sensitivity to the commonly used antibiotics in a dairy farm in Taizhou City.[Method]Nine milk samples were recovered from the dairy cows with mastitis.The bacterial strains were isolated with Baird-Parker agar medium,and the obtained isolates were subjected to phenotypic indentification by biochemical reactions as well as molecular comfirmation by PCR assay.Furthermore,the antimicrobial sensitivity test of the isolates were carried out.[Result]Six Staphylococcus strains were obtained and identified using the coagulase test and 16S rDNA sequencing,three of which were comfirmed as Staphylococcus aureus.According to antimicrobial sensitivity test,all three strains of Staphylococcus aureus were resistant to penicillin G,two strains were resistant to tetracycline,and two strains were intermidiate to erythromycin and oxacillin.[Conclusion]The Staphylococcus aureus isolates were mostly resistant to penicillin G and tetracycline,but susceptible to the other tested antibiotics.