一株水貂源致病性粪肠球菌分离与鉴定

摘要

对水貂肠淋巴结中分离得到的一株新细菌性病原进行分离鉴定，并作形态学和培养特征观察、生化试验、16S rRNA基因 PCR 鉴定、药物敏感试验、致病性试验。结果表明，该分离株可确定为粪肠球菌（Enterococcus faecalis），其16S rRNA基因序列与GenBank中从猪、羊、鸡、牛、马等动物体内分离出的粪肠球菌基因同源性均在97%以上，且与猪源粪肠球菌亲缘关系最近。药物敏感试验表明，分离菌株对头孢曲松钠、万古霉素、阿莫西林、庆大霉素、多西环素、环丙沙星、左氟氧沙星、诺氟沙星、氟苯尼考、红霉素高度敏感，对其他19种抗生素具有明显抗性。致病性试验表明，分离菌株对小鼠有较强致病性。毒力基因检测结果表明，其携带cylA、gelE和efaA三种毒力基因。这是从水貂中分离得到致病性粪肠球菌的首次报道，研究结果可作为水貂与肠球菌相关疾病检测、鉴别、诊断、治疗和预防依据。%A strain of bacteria isolated from mink intestinal lymph node was identified by biological method. The isolate was identified by phenotypical test, biochemical test, 16S rRNA gene sequence characterization, antibiotics susceptibility test and pathogenicity test for further characterization. The isolate was identified as Enterococcus faecalis by morphological and biochemical test, 16S rRNA gene sequence homologous comparisons were higher than 97%to those genes of E. faecalis from pig, sheep, chicken, cow, horse and other animals in GenBank. The isolate with broad-spectrum resistance to antibiotics, could lethal to mice with three virulence genes of cylA, gelE and efaA. This was the first time to report pathogenicity Enterococci faecalis isolated from mink, the results could be used as the base of the detection, diagnosis, treatment and prevention of Enterococcus related diseases in mink.