牦牛源表皮葡萄球菌的分离鉴定和生物学特性研究

Isolation,Identification and Biological Characteristics of Staphylococcus epidermidis from Yak

为了解西藏拉萨地区牦牛源表皮葡萄球菌的携带情况,本试验随机采集了26份拉萨地区牦牛鼻拭子样品,采用细菌分离纯化和形态学鉴定、生化鉴定以及16S rDNA测序和同源性比对分析对分离菌株进行鉴定;选取19种常用抗生素,利用K-B药敏纸片扩散法对分离菌株进行药敏试验;检测四环素类耐药基因tet(M)和tet(K),林可胺类、氯霉素类、截短侧耳素类、恶唑烷酮类、链阳霉素A类多药耐药基因cfr,β-内酰胺类耐药基因mecA和酰胺醇类耐药基因fexA五种耐药基因,研究分离菌株的耐药性;进行攻毒试验,检测分离菌株的致病性。结果显示,分离得到1株表皮葡萄球菌,命名为LZ-1;LZ-1对氨苄西林、青霉素和红霉素耐药,对多黏菌素B、头孢他啶和克林霉素中介,对头孢曲松、四环素和新霉素等13种抗生素敏感;共检测出tet(M)、tet(K)和mecA三种耐药基因;该菌株对小鼠致病性不强。结果表明,本试验分离出1株牦牛源表皮葡萄球菌,有一定的耐药性,可为其防治提供一定的参考。

To understand the carrying status of Staphylococcus epidermidis in yaks from Lhasa,Tibet,26 nasal swab samples were randomly collected from yaks in the Lhasa area.The isolates were identified using bacterial isolation and purification,morphological identification,biochemical identification,16S rDNA sequencing,and homology comparison analysis.The antimicrobial susceptibility of the isolates was tested using the K-B disc diffusion method with 19 commonly used antibiotics.The presence of tetracycline resistance genes tet(M)and tet(K),multidrug resistance genes cfr of lincoamine,chloramphenicol,truncated pleurin,oxazolidinone and streptomycin A,β-lactam resistance genes mecA and aminoalcohol resistance genes fexA in the isolates was examined to study their resistance profiles.Pathogenicity tests were conducted to evaluate the virulence of the isolates.The results showed that one strain of Staphylococcus epidermidis was isolated and named LZ-1.LZ-1 was resistant to ampicillin,penicillin,and erythromycin,intermediate sensitive to polymyxin B,ceftazidime and clindamycin,and sensitive to 13 other antibiotics including ceftriaxone,tetracycline,and neomycin.The resistance genes tet(M),tet(K),and mecA were detected.The strain exhibited low pathogenicity in mice.The results indicate that one strain of Staphylococcus epidermidis from yaks was isolated,with some antibiotic resistance,providing a reference for its prevention and treatment.