[clpE基因缺失对肺炎链球菌毒力的影响]

[Effect of clpE gene deletion on virulence of Streptococcus pneumoniae].

作者信息

Zhang Qun, Yin Nanlin, Xu Wenchun, Wang Hong, Pang Dan, Yang Xiaoliang, Yin Yibing, Zhang Xuemei

机构信息

Key Laboratory of Medical Diagnostics, Ministry of Education, Chongqing Medical University, Chongqing 400016, China.

出版信息

Wei Sheng Wu Xue Bao. 2009 Feb;49(2):233-8.

PMID:19445180

Abstract

OBJECTIVE

To study the effect of clpE gene deletion on the virulence of Streptococcus pneumoniae.

METHODS

The clpE-deficient strain was constructed by LFH-PCR and identified by PCR and sequencing. The impact of clpE mutant on the virulence of S. pneumoniae was evaluated in a mouse model. In addition,we also studied the effect of clpE mutant on adherence and invasion of host cells. Real time RT-PCR was used to measure the mRNA expression levels of autolysin A, pneumococcal surface adhesion A, pneumolysin, pneumococcal surface protein A and neuraminidase.

RESULTS

The clpE gene was replaced completely by erm cassette. Mice virulence experiments showed that the median lethal time of the wide-type was 54 h, whereas that of clpE mutant was 21d (P < 0.01). Cell culture infection experiments indicated that adherence and invasion of clpE mutant were strongly reduced (P < 0.05). The expression of virulent factors in clpE mutant was lower than that of the wild-type (P < 0.05).

CONCLUSION

ClpE is involved in virulence by modulating the expressions of virulence factors.

摘要

目的

研究clpE基因缺失对肺炎链球菌毒力的影响。

方法

通过长片段同源重组PCR（LFH-PCR）构建clpE基因缺失菌株，并通过PCR和测序进行鉴定。在小鼠模型中评估clpE突变体对肺炎链球菌毒力的影响。此外，还研究了clpE突变体对宿主细胞黏附与侵袭的影响。采用实时逆转录PCR检测自溶素A、肺炎球菌表面黏附素A、肺炎溶血素、肺炎球菌表面蛋白A和神经氨酸酶的mRNA表达水平。