聚合酶链反应(PCR)方法检测远缘链球菌

Detection of Streptococcus sobrinus by polymerase chain reaction

目的 :建立一种快速、特异、敏感的远缘链球菌PCR检测方法。方法 :根据已发表的远缘链球菌葡聚糖酶基因 (dexA)的特异片断设计一对寡核苷酸引物 ,对 12种变形链球菌群中包含a～h 8种血清型的细菌及 2 3种常见的口腔菌中进行PCR扩增 ,扩增产物电泳鉴定 ,并对特异片断进行回收 ,测序。结果 :变形链球菌群标准菌株中 ,只有远缘链球菌 (血清d、g型 )产生特异的扩增片断 ,测序结果与已发表的文献结果完全一致 ,且显示了极高的灵敏性 ,≥ 2× 10 2 个细胞均可以用该方法检出。结论 :PCR方法可以用于快速灵敏的检测远缘链球菌 。

Objective: To develop a PCR method for detecting S treptococcus sobrinus (S.s) in conventional culture. Method: A pair of specific primers were designed from the dexA gene of S.s , the genome DNA of 12 strains of Mutans Streptococci (8 serotypes from a ～h) and 23 species of the bacteria which were commonly found in oral cavity wer e tested by PCR amplification, the PCR products were identified by electrophore sis. Result: Only S.s of serotype d and g could produ ce 277 bp DNA fragments, and the PCR method could detect less than 1 000 copies of S.s. Conclusion: PCR method is specific and sen sitive in the detection of S.s.