肺炎链球菌不同生长时间自溶素lytA基因表达的差异性分析  

Differences in expression of the autolysin lytA gene of Streptococcus pneumoniae in different stages of growth

作　　者：谢兴凤 孟圆[2] 杨光[2] 孙文平[2] 罗红[2] 任艳[1] 蒋久怡 XIE Xing-feng MENG Yuan YANG Guang SUN Wen-ping LUO Hong REN Yan JIANG Jiu-yi(Mianyang Central Hospital, Mianyang, Sichuan 621000, China Department of Clinical Immunolo- gy and Microbiology, Dalian Medical University)

机构地区：[1]四川省绵阳市中心医院,四川绵阳621000 [2]大连医科大学临床免疫与微生物教研室,辽宁大连116044

出　　处：《中国病原生物学杂志》2017年第5期394-396,401,共4页Journal of Pathogen Biology

基　　金：四川省卫计委科技基金资助项目(No.16PJ188)

摘　　要：目的探讨肺炎链球菌lytA基因在细菌生长的不同时间点的表达差异。方法根据GenBank中肺炎链球菌M66株的lytA基因序列(FN 549899.1)设计并合成引物,选取17个生长时间点,分别提取肺炎链球菌的总RNA,采用实时荧光定量PCR技术(QRT-PCR)检测lytA基因在不同生长时间点的相对表达量,利用溶解曲线观察扩增反应特异性,采用双标准曲线法进行数据分析。结果经过内参基因16SRNA校正后,肺炎链球菌lytA基因相对表达量从生长的18h-96h呈现逐渐升高的趋势,96h时达到高峰,与其他时间点比较差异有统计学意义(P<0.05)。之后开始下降,144h生长点出现第二次升高趋势。结论不同生长时间点肺炎链球菌lytA基因表达量存在差异,与细菌培养时菌落表现的自溶现象相关,为进一步研究lytA基因与肺炎链球菌自溶现象的相关性奠定了基础。Objective To investigate the expression of an autolysin gene （lytA） at different times during the growth of Streptococcus pneumoniae. Methods Specific primers were designed and synthesized in accordance with the sequence of the lytA gene of the M66 strain registered in GenBank （FN549899.1）. Total RNA was extracted from samples collected at 17 time points during the growth of S. pneumoniae. The relative expression of lytA gene at different times during the growth of S. pneumoniae was determined with real-time quantitative RT-PCR （QRT-PCR）. The specificity of amplifica- tion was analyzed using a dissociation curve, and the data were analyzed using the standard curve method. Results Af- ter calibration with a reference gene （16S RNA）, the relative expression of S. pneumoniae LytA gene tended to increase after growth for 18-96 h and peaked at 96 h. Expression of the LytA gene at that time differed significantly from expres- sion at all other times during the growth of S. pneumoniae （P〈0.05）. Expression then began to decrease, but a second peak appeared after 144 h. Conclusion The level of expression of the lytA gene differed at different times during the growth of S. pneumoniae. This may be related to autolysis during bacterial culture. This work has laid the foundation for the further study of correlation between the lytA gene and S. pneumoniae autolysis.

关 键 词：肺炎链球菌 实时荧光定量PCR lytA基因 

分 类 号：R378.12[医药卫生—病原生物学]