猪链球菌2型HA0609的分离及致病性研究

Isolation and pathogenicity of Streptococcus suis type 2 strain HA0609

从江苏省某屠宰场猪的扁桃体中分离到1株细菌,通过培养特性、菌体形态、菌落形态、染色特性、生化试验以及荚膜多糖(cps)基因的PCR检测,确定为猪链球菌2型,命名为HA0609。本试验针对猪链球菌7种主要毒力因子——谷氨酸脱氢酶(gdh)、溶菌酶释放蛋白(mrp)、胞外因子(epf)、溶血素(sly)、纤连蛋白/血纤蛋白原结合蛋白(fpbs)、次黄嘌呤核苷酸脱氢酶(impdh)及毒力相关序列orf2,进行PCR检测。与已知强毒株比较,该菌株2种主要毒力因子sly和epf均为阴性。动物试验显示HA0609对猪、兔和Balb/c鼠均无致病性。

One bacterial strain was isolated from tonsillar specimen of a slaughtered healthy pig in Jiangsu province, and identified as Streptococcus suis type 2 based on morphological, cultural and biochemistry characteristics, and PCR detection of capsular polysacchafide （cps）. The isolate was named as HA0609. The genes of seven virulence factors, including glutamate dehydrogenase （gdh） , extracellular factor （epf）, muramidase-released protein （mrp）, suilysin （sly）, fibronectin-binding protein （fpbs）, inosine 5-monophosphate dehydrogenase gene （impdh） and virulence-associated sequence off2, were detected by PCR amplification. Animal pathogenicity of HA0609 was compared with two virulent strains of S. suis type 2. The results showed that two mainly virulent factor genes sly and epf could not be detected in HA0609. And animal pathogenicity test showed that HA0609 could not cause piglets, rabbits and Balb/c mice to death.