一株羊源致病性屎肠球菌的分离鉴定及耐药性分析  

Isolation,Identification and Drug Resistance Analysis of Pathogenic Enterococcus feacium of Sheep

作　　者：刘永安[1] 李学瑞[1] 周建华[1] 马丽娜[1] 刘永生[1] 

机构地区：[1]中国农业科学院兰州兽医研究所,家畜疫病病原生物学国家重点实验室,农业部草食动物疫病重点开放实验室,兰州730046

出　　处：《中国畜牧兽医》2017年第2期530-537,共8页China Animal Husbandry & Veterinary Medicine

基　　金：国家自然科学基金(31172335)

摘　　要：试验从甘肃肃南县某羊场死亡羊中分离出疑似某球菌菌株XCP,为进一步确定该致病菌株及其耐药性情况,进行了病原菌分离、革兰氏染色、生化试验、16SrRNA PCR扩增鉴定、小鼠致病力试验、药敏试验、毒力基因和耐药基因扩增试验研究。结果发现,该菌革兰氏染色阳性,高盐、蜜二糖、蔗糖等生化反应阳性,VP、马尿酸盐、阿拉伯糖等生化反应阴性;16SrRNA基因PCR扩增后,进行BLAST比对,结果与GenBank中的屎肠球菌16SrRNA基因序列同源性为100%;小鼠致病力试验发现,该菌株具有很强的致病性;该菌株对β-内酰胺类抗生素苯唑西林、青霉素G,喹诺酮类抗生素诺氟沙星、环丙沙星、左氟沙星,以及四环素等高度耐药,对红霉素、万古霉素、克林霉素等抗生素敏感;毒力基因Asal、cylA、acm和耐药基因TetM、ant(6)-Ⅰ、aac(6′)-aph(2′′)、ermB扩增均为阳性。结果表明,该菌为屎肠球菌(Enterococcus faecium),具有较强的致病性和耐药性,可能与毒力基因和耐药基因的高阳性率有关。To further identify the pathogenic strains and analyze their antibiotic resistance,the methods of pathogen isolating,the methods of Gram staining,biochemical tests and 16 SrRNA PCR amplification,virulence tests,drug sensitive tests,virulence genes and resistance genes PCR amplification were used.The results showed that the strain was Gram-positive and revealed positive after reacting with 6.5% NaCl,melibiose,sucrose and etc.,while revealed negative reactions with VP,hippurate,arabinose and etc..It showed 100%similarity with Enterococcus feacium 16 SrRNA gene sequence in GenBank after PCR amplification of 16 SrRNA gene and BLAST alignment.It was found severe pathogenicity after virulence tests in mice.The strain was highly resistant to oxacillin,penicillin G ofβ-lactam antibiotics and norfloxacin,ciprofloxacin,levofloxacin of quinolones antibiotics and tetracycline,while was sensitive to antibiotics of erythromycin,vancomycin and clindamycin.It revealed that virulence factor genes Asal,cylA,acm and resistance genes TetM,ant（6）-Ⅰ,aac（6′）-aph（2′′）,ermBshowed positive.The results showed that the bacteria was Enterococcus feacium,it had a strong pathogenicity and severe drug resistance,which might be related to the highly positive rates of virulence genes and drug resistance genes.

关 键 词：屎肠球菌 分离鉴定 耐药性 毒力因子 耐药基因 

分 类 号：S852.611[农业科学—基础兽医学]