毒力基因pspA在肺炎链球菌入侵血液系统中的作用研究  

Role of virulence gene pspA in invasion of Streptococcus pneumoniae into blood system

作　　者：胡大康[1] 张瑾[1] 王冬国[1] 刘池波[1] 曲颖[1] 罗新华[1] 刘双春[1] 杨锦红[1] 李向阳[1] 

机构地区：[1]台州市立医院检验科,浙江台州318000

出　　处：《中华医院感染学杂志》2014年第8期1821-1823,1826,共4页Chinese Journal of Nosocomiology

基　　金：浙江省医药卫生研究计划基金资助项目(2013KYA230)

摘　　要：目的研究不同来源肺炎链球菌(SPN)刺激THP-1细胞和A549细胞前、后毒力基因pspA表达的变化,探讨其在SPN入侵血液中的作用。方法从住院患者分离、搜集23株SPN,与SPN标准株ATCC49619一起进行培养,并提取RNA;THP-1和A549细胞经培养后调至一定浓度,再分别用上述24株SPN在37℃5%CO2环境下分别刺激4h和8h;然后,搜集细胞悬液进行离心,沉淀物用于RNA的提取;用荧光实时定量逆转录PCR法对刺激前、后毒力基因pspA的mRNA与16srRNA进行同时测定,用SPSS17.0软件进行数据分析。结果临床SPN刺激THP-1和A549细胞后毒力基因pspA的△Ct值均低于刺激前;临床SP株毒力基因pspA的△Ct值与ATCC49619间,血源性和痰源性SPN相比,刺激细胞后psaA的△Ct值间差异均有统计学意义(P<0.05)。结论临床SPN刺激THP-1和A549细胞后毒力基因pspA的表达均有上调,临床SPN株毒力基因pspA的表达与ATCC49619不同;毒力基因pspA表达的异化可能是血源性SPN入侵血液的原因之一。OBJECTIVE To investigate the expression of pspA virulence gene in different Streptococcus pneumoniae before and after its stimulation of THP-1 monocytes and A549 pneumocytes and its role in facilitating SPN invasion into host blood system. METHODS Totally 23 strains of S. pneumoniae were collected from hospitalized patients, then such strains and ATCC49619 were cultured and purified for RNA. THP-1 monocytes and A549 pneumocytes were resuspended at certain concentrations after culture and collection, which were stimulated at 37℃ 5% CO2 for 4h and 8h respectively. The suspensions were then collected and centrifuged. The sediments were used for the purification of RNA. Real-time quantitative reverse transcription PCR assay was used to analyze mRNA of pspA as well as 16s rRNA before and after stimulation of THP-1 monocytes and A549 pneumocytes by SPN. The data were analyzed by using SPSS 17.0. RESULTS The values of△Ct for pspA were all less after stimulation than those before stimulation of THP-1 monocytes and A549 pneumocytes by clinical S. pneumoniae. The △Ct values of pspA showed statistical difference between clinical S. pneumoniae and ATCC49619 ; there was stasitial difference in the △Ct values of pspA between blood-derived SPN and sputum-derived SPN after stimula- tion（P〈0.05）. CONCLUSION The expression of pspA in clinical S. pneumoniae is increased after its stimulation of THP-1 monocytes and A549 pneumocytes. The expression of pspA in clinical S. pneumoniae is different from that in ATCC49619. The heterogeneous expression of pspA virulence gene may aid in the invasion of blood system by blood-derived S. pneumoniae.

关 键 词：肺炎链球菌 逆转录PCR 毒力基因 

分 类 号：R378.12[医药卫生—病原生物学]