猪源2型链球菌福建株CPS2J基因PCR检测及序列分析

设计并合成一对扩增2型猪链球菌CPS基因的特异性引物，以猪2型链球菌福建株DNA为模板，筛选最佳反应条件，建立检测CPS2J基因的PCR方法，并对PCR扩增产物进行序列测定和同源性比较分析。结果如下：应用该方法对猪2型链球菌福建株和标准阳性株进行扩增，均获得与预期大小一致的675bp特异性目的片段，而对8株非2型猪链球菌的扩增结果均呈阴性；敏感性测定最低可检出100cfu细菌量或50pg 细菌DNA；SS2PFJ06CPS2J 基因部分核苷酸及其推导的氨基酸序列与猪链球菌2型不同菌株的同源性分别达98.7%-100%和97.8%~100%。上述结果表明建立并优化的猪2型链球菌CPS2J基因的PCR检测方法敏感性好、特异性高，能用于2型猪链球菌的分子流行病学调查和快速检测； 序列分析表明猪2型链球菌福建株与国内外8株标准株之间同源性高、亲缘关系密切。

PCR Detection and sequence analysis of CPS2J gene for Fujian strain Streptococcus suis serotype 2

Through synthesizing a part of specific primers, the PCR was established by means of the template of DNA from SS2 Fujian strain, We developed the PCR method to detect Streptococcus suis serotype 2(SS2) from pig, and the CPS2J partial gene was sequenced and blasted. The results were: The 675bp fragment from SS2PFJ06 and standard positive SS2 was amplified by the PCR, as well as expecting fragment. However, 8 strains not SS2 were not amplified to the 675bp fragment. The PCR detected less 100cfu of bacterium quantity or 50pg of genic DNA through the sensitive test. The blast of the sequence of PCR product achieved to 98%-100% homology with that of other SS2 strains, amino acid sequence achieved to 91.6%~93.3%. The results reveals the PCR developed were sensitive and specific and applied to the SS2 diagnosis and epidemiology investigation. Sequence analysis indicated homology between SS2 Fujian strain and 8 SS2 at home and abroad was high and genetic relationship was close.