青海省某奶牛场乳房炎致病菌的分离鉴定和耐药性分析

Isolation,Identification and Drug Resistance Analysis of Mastitis Pathogens in Dairy Farm from Qinghai Province

为了调查青海省某奶牛场乳房炎致病菌种类及其耐药情况,本试验从青海省西宁市某奶牛场采集临床型乳房炎、隐性乳房炎和正常乳样共计106份,进行细菌分离和鉴定后,用琼脂扩散法检测病原菌对临床常用抗菌药的敏感性。结果显示:从乳样中分离到的204株优势细菌主要为乳酸乳球菌、马葡萄球菌、产色葡萄球菌、干燥棒状杆菌、无乳链球菌、粪肠球菌和金黄色葡萄球菌;药敏试验显示,马葡萄球菌对阿莫西林、四环素、头孢唑林和美罗培南敏感,对庆大霉素、林可霉素和卡那霉素存在不同程度耐药;产色葡萄球菌对庆大霉素以外的大部分药物高度敏感;无乳链球菌对头孢唑林、阿莫西林和美罗培南敏感,而对卡那霉素和诺氟沙星耐药;粪肠球菌对青霉素类药物敏感性高,而对卡那霉素、诺氟沙星、庆大霉素和林可霉素耐药;金黄色葡萄球菌对四环素和美罗培南敏感,对庆大霉素和林可霉素耐药。结果表明,该牛场乳房炎致病菌以革兰阳性菌为主,对头孢类药物多保持敏感,对其他类型抗菌药存在不同程度耐药,链球菌和肠球菌对青霉素普遍耐药,应引起临床重视。本试验结果为该养殖场更好地防控奶牛乳房炎和临床合理用药提供了科学依据。

In order to investigate the pathogen distribution and drug resistance of mastitis in dairy farm in Qinghai Province,this study collected 106 clinical mastitis,subclinical mastitis and normal milk samples from local dairy farms in Xining City,Qinghai Province,bacteria were isolated and identified,and the susceptibility of pathogenic bacteria to commonly used antibiotics was assessed by agar-diffusion method.The results showed that the 204 strains isolated from the 106 milk samples were mainly Lactococcus lactis,Staphylococcus equorum,Staphylococcus chromogenes,Corynebacterium xerosis,Streptococcus agalactiae,Enterococcus faecalis and Staphylococcus aureus.In the drug sensitivity test,S.equorum was sensitive to amoxicillin,tetracycline,cefazolin and meropenem,but resistant to gentamicin,lincomycin and kanamycin at varying degrees;S.chromogenes was sensitive to most antibiotics except gentamicin;S.agalactiae was sensitive to cefazolin,amoxicillin and meropenem,but resistant to kanamycin and norfloxacin;E.faecalis was highly sensitive to penicillins,but resistant to kanamycin,norfloxacin,gentamicin and lincomycin;S.aureus was sensitive to tetracycline and meropenem,but resistant to gentamicin and lincomycin.Thus,the main pathogens in the farms are Gram-positive bacteria,which are mostly sensitive to cephalosporins,and display different degrees of resistance to other antibiotics.Streptococcus and Enterococcus strains are generally resistant to penicillin,and deserve more attention.These data provide new insights for rational drug use to prevent and control dairy cow mastitis in dairy farms.