血清群6肺炎链球菌分子分型与耐药特征研究

目的 比较不同方法鉴别血清群6肺炎链球菌不同血清型的能力,了解血清群6肺炎链球菌的耐药性与分子特征。 方法 采用荚膜肿胀分型方法与聚合酶链反应(PCR)分型方法鉴别33株血清群6肺炎链球菌的血清型及相应的基因型;检测菌株对6种常用抗生素的敏感性;采用脉冲场凝胶电泳(PFGE)方法分析不同血清型菌株的基因组特征。 结果 PCR分型方法与传统的血清学分型方法结果一致。全部菌株对阿奇霉素均耐药,对利福平及左氧氟沙星均敏感;6B型菌株呈现较高的多重耐药特征。根据PFGE带型特征,所有菌株可分为2个簇,6C菌株之间、6B菌株之间带型呈现较高相似性。 结论 PCR分型方法可用于鉴别血清群6菌株的不同血清型;菌株耐药情况严重,且大多数菌株呈多重耐药特征;PFGE对鉴别肺炎链球菌不同菌株间的差异有较高的分辨率。

Molecular typing and drug resistance of Streptococcus pneumoniae serogroup 6

Objective To evaluate the performance of 2 methods to identify serotypes of Streptococcus pneumoniae serogroup 6 and understand the drug susceptibility and molecular characteristics of S.pneumoniae serogroup 6.MethodsQuellung method and PCR assay were conducted to identify serotypes and related genotypes of 33 strains of S.pneumoniae serogroup 6,the drug susceptibility test to 6 common antibiotics was conducted for these strains and pulsed field gel electrophoresis(PFGE) was performed to analyze the genome characteristics of S.pneumoniae with different serotypes.Results The serological detection results of quellung method and PCR assay were consistent.All the strains were resistant to azithromycin,but sensitive to rifampin and levofloxacin.The drug resistant rate in strains of serotype 6B was higher.According to the PFGE patterns,the 33 strains were in 2 clusters.The PFGE patterns were quite similar between 6C strains and 6B strains.Conclusion PCR assay could be used to identify the serotypes of S.pneumoniae serogroup 6 instead of quellung method.The drug resistance of S.pneumoniae strains detected was very serious,and most of them were multi drug resistant.PFGE is quite sensitive in identifying the differences of S.pneumoniae with different serotypes.