一株血清7型致病性猪链球菌的分离鉴定

摘要

A bacteria was isolated by blood agar culturing from afacted swine brain and was characterized by morphological observation, biochemical test, PCR and serology test. The results showed that the bacteria isolate was identified as Streptococcus suis serotype 7 with virulent genotype of eps7H+, gdh+, mrp+, ef, sly, designated 07WC11. Zabresh and piglets infection experiments were performed to determine its virulence. The experimental infection results indicated that the isolate was pathogenic to zabresh and piglets and more virulent than that of standard S. Suis strains of R735 and 8074.%为确定2007年11月黑龙江省五常市某猪场发病猪的病原,本研究将病猪迫杀,采取脑和关节液在血平板培养基上划线进行细菌分离培养,结果显示在血平板培养基上形成灰色、半透明、边缘整齐的有草绿色狭窄溶血环的光滑型圆形小菌落,镜检观察到散在排列的革兰氏阳性短链球菌,经生化反应、PCR反应及血清学试验鉴定为7型猪链球菌,并命名为07WC11株,其毒力基因型为cps7H+、gdh+、mrp+、ef和sly.以纯化的该分离菌株对斑马鱼和仔猪进行动物感染试验均能够导致斑马鱼和仔猪发病,表明该菌株具有一定的致病性,其毒力比国际标准菌株R735株和8074株更强.