1株猪链球菌的分离·鉴定及其毒力因子研究

Identification of a Strain of Streptococcus suis and the Main Virulence Factors Analysis

[目的]对1株疑似猪链球菌菌株进行鉴定,为进一步研究猪链球菌的毒力提供理论基础。[方法]采用革兰氏染色镜检、形态观察和16S rDNA测序后NCBI数据库Blast比对鉴定菌株;另外选取猪链球菌7种主要毒力因子设计引物,利用PCR方法检测其毒力基因分布情况。[结果]显微镜下该疑似菌株为革兰氏阳性菌,多数呈链状,少见单个排列。16S rDNA测序结果与猪链球菌2型同源性达到99%。毒力因子检测均含有7种毒力因子。[结论]该疑似菌株为猪链球菌2型,其毒力基因型为:gdh+/ef+/mrp+/sly+/fbps+/orf2+/cps2J+/。

[Objective] To identify a Streptococcus strain,so as to provide theoretical basis for further studying the toxicity of Streptococcus suis.[Method] The identification of the strain was performed by Gram stain and microscopy,and 16S rDNA gene sequence analysis.Seven main virulence genes were selected to design primers and the virulence gene distribution was detected by PCR.[Result] The strain was Gram positive bacterium,presenting chain-like distribution.The 16S rDNA sequence of the strain was above 99% of homology to Streptococcus suis 2.[Conclusion] The isolated strain was Streptococcus suis 2.The virulence genotype of this SS2 was： gdh＋/ef＋/mrp＋/sly＋/fbps＋/orf2＋/cps2J＋/.