肺炎链球菌毒力基因检测与临床研究

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

目的了解肺炎链球菌10种常见毒力基因(pspA、pspC、lytA、lytB、rrgA、nanA、pav、iga、ply、hysA)在临床分离菌株中的分布,为研究其在致病过程中的作用机制、新型疫苗研制提供参考。方法选取2013年1月-2014年12月从南京医科大学附属无锡人民医院临床分离的20株肺炎链球菌为研究菌株,采用PCR法对10种靶基因进行检测,统计并分析各毒力基因表达阳性率及其与细菌耐药性之间的关系,数据采用SPSS 17.0软件进行统计分析。结果 10种毒力基因在20株肺炎链球菌中表达阳性率分别为0、0、45.0%、60.0%、35.0%、60.0%、75.0%、80.0%、55.0%及55.0%,其中pav、iga阳性率对较高;红霉素耐药菌株中rrgA及pav的阳性率分别为64.5%、100.0%,显著高于非耐药菌株(P<0.05)。结论 10种毒力基因在肺炎链球菌中有不同程度的表达,其中pav、iga阳性率较高,可能成为新型疫苗的候选分子;rrgA及pav可能与肺炎链球菌对红霉素耐药有关。

OBJECTIVE To investigate the distribution of virulence genes（pspA,pspC,lytA,lytB,rrgA,nanA,pav,iga,ply and hysA）among Streptococcus pneumoniae isolated from clinical patients so as to provide important reference for the research on the roll of virulence genes in the pathogenesis of the S.pneumoniae and the development of new vaccine.METHODS Totally 20 strains of S.pneumoniae were isolated from patients in Wuxi People′s Hospital from Jan.2013 to Dec.2014.Polymerase chain reaction（PCR）was used to screen for the ten target virulence genes.The positive rate of the virulence genes and the relationship with the bacterial drug resistance were statistically analyzed.SPSS 17.0was explored to make statistical analysis.RESULTS The positive rates of ten virulence genes in 20 clinical isolates were respectively 0,0,45.0%,60.0%,35.0%,60.0%,75.0%,80.0%,55.0%,and 55.0%.Among them,positive rates of pav and iga were relatively higher.The positive rates of pav（64.5%）and rrgA（100.0%）in erythromycin resistant strains were significantly higher than those of non resistant strains（P〈0.05）.CONCLUSIONThe ten virulence genes each have different levels of expression in S.pneumoniaein this region.The detection rate of pavand igawas relatively higher,which may become new vaccine candidate molecules.RrgAand pav may be related to erythromycin resistance.