临床分离肺炎链球菌的毒力基因及血清型分析

目的 了解肺炎链球菌的5种常见毒力基因(psaA、pspA、nanA、ply、lytA)在临床分离株中的分布情况.方法 以2006-2008年从临床分离133株肺炎链球菌为研究对象,采用PCR法对5种常见的毒力基因进行检测.结果 lytA、psaA、nanA、pspA、ply这5种基因在133株菌中的检测阳性率分别为94.7%、85.0%、84.2%、60.2%、82.7%;5种毒力基因在87株常见血清型菌中的阳性率分别为100%、87.4%、89.7%、67.8%、86.2%.结论 5种毒力基因在本地区肺炎链球菌中的阳性检测率均较高,在常见血清型菌株中的阳性检测率较其他血清型高.这5种基因是肺炎链球菌致病的主要毒力基因,可能作为新刑肺炎蛋白疫苗的候选基因.

Prevalence of virulence genes in Streptococcus pneumoniae strains isolated from clinical patients

Objective To investigate the prevalence of virulence genes(ply, pspA, nanA, lytA, psaA) among Streptococcus pneumoniae recently isolated from clinical patients. Methods The 133 strains were isolated from patients in three teaching hospitals in Chongqing from 2006 to 2008. Polymerase chain reaction was used to screen for virulence genes (ply, pspA, nanA, lytA, psaA). Results The positive rate of lytA, psaA, ply, nanA and pspA in 133 clinical isolates were 94.7%, 85.0%, 82.7%, 84. 2% and 60.2%, respectively. The positive rates of the lytA, psaA, ply, nanA and pspA genes in 87 common serotypes isolates was 100%, 87.4%, 86.2%, 89.7%, 67.8%, respectively. Conclusion The total positive rates of five virulence genes in the 133 clinical strains were high. The positive rates of five genes in the com-mon serotypes isolates were higher than those in the no-common serotypes. These genes are important virulence genes of Streptococcus pneumoniae. They could be candidates for protein vaccine of Streptococcus pneumoniae.