一株猪源棒状杆菌的分离及其16S rRNA基因分析鉴定

四川某商品猪场仔猪出现以体温升高,背、腹和腿部皮肤发绀,淋巴结出血肿大,肺、脾脏出血、化脓为主要特征的疾病。通过对分离细菌的纯化培养、形态学观察、生化试验、致病性试验和药物敏感性试验,鉴定出一株致病菌。应用通用引物对其16S rRNA基因进行克隆和序列分析,序列在NCBI上进行BLAST比对,选择同源性较高的棒状杆菌属中25株不同种的菌株16S rRNA序列进行比对分析,构建遗传进化树。分离纯化的细菌在鲜血琼脂平板厌氧条件下生长良好,为革兰氏染色阳性杆状菌,能发酵部分糖类,能致死小白鼠,对头孢类抗生素敏感,16S rRNA序列与棒状杆菌属细菌的同源性最高,在78.2%~98.0%之间,遗传进化树分析结果表明,该菌株与棒状杆菌属细菌属于同一分类群,分离菌鉴定为棒状杆菌。

Isolation of Swine Corynebacterium and its Identification by Analysis of 16S rRNA Gene

An infectious disease mainly characterized of fervescence, cyanosis skin, lymphadenectasis, swollen lungs, splenomegaly, bleeding and purulent occurred in a breeding farm in Ya’an in the province of Sichuan. A pathogen was isolated by blood agar culturing, and characterized by morphological observation, biochemical test, antibiotic sensitive test and 16S rRNA gene sequence analysis. The 16S rRNA gene sequence was compared with sequences of other 25 reference bacteria belonging to Corynebacterium. The results showed that the isolated bacteria was G+, rod-shaped,and sensitive to the cephalosporin antibiotics,the homology analysis showed that the homology between isolated bacterium and other strains of Corynebacterium was from 78.2% to 98.0%. Through phylogenetic analysis, the isolated bacteria was identified as Corynebacterium.