摘要
目的研究双组分信号调控系统saeRS对金黄色葡萄球菌临床分离株a溶血素基因（hla）和Panton．Valentine杀白细胞素基因（1ukSIF-PV）表达的影响。方法利用同源重组技术敲除saeRS基因，获得金黄色葡萄球菌saeRS基因敲除株，并构建saeRS回复突变株。应用SDS-PAGE检测金黄色葡萄球菌saeR／S野生株、敲除株及回复突变株分泌蛋白的变化，采用RT—PCR检测金黄色葡萄球菌saeR／S野生株、敲除株及回复突变株hlamRNA和lukS—PVmRNA。结果成功构建了金黄色葡萄球菌saeRS基因敲除株SA75AsaeRS。与野生株SA75相比，SA75／XsaeRS的生长无明显差异，但分泌蛋白种类和数量有明显减少且溶血能力明显减弱。saeRS基因回复突变株SA75／XsaeRS—C可以基本恢复敲除株的溶血能力。在3、6和10h3个时间点与野生株相比，SA75AsaeRS的hlamRNA均有明显下降，分别是野生株的7．6％、0％和0．1％。lukS—PVmRNA也均有明显下降，分别是野生株lukS—PV表达量的37．2％、19．2％和20．4％。结论saeRS基因是调节金黄色葡萄球菌分泌蛋白的关键因子。saeRS基因对金黄色葡萄球菌的hla和lukS—PV的表达具有正调控作用。
Objective To investigate regulating effect of saeRS on the expression of hla and lukS- PV in Staphylococcus aureus clinical isolate. Methods The homologous recombination technology was used to achieve saeRS knockout S. aureus clinical isolate （SA75 asaeRS）, and to construct saeRS reverse mutant （ SA75 AsaeRS-C）. SDS-PAGE and RT-PCR were used for detecting changes of secretory proteins and chan- ges of hla mRNA and lukS-PV mRNA in SA75 wild type （SA75WT）, SA75 AsaeRS and SA75 AsaeRS-C. Results Compared with SA75WT, SA75 AsaeRS, the successfully constructed saeRS knockout strain, showed no distinct difference in growth curve, but a significant decrease in secretory protein types and quan- tity. The hemolytic ability was inhibited in SA75 asaeRS, but could be restored in SA75 AsaeRS-C. The hla mRNA levels of SA75 AsaeRS at 3, 6 and 10 hours were significantly decreased to 92.4 %, 100% and 99.9% of those of SA75WT respectively, and the levels of lukS-PV mRNA were decreased to 62. 8%, 81.8% and 79.6% respectively. Conclusion saeRS was a key factor in regulating secretory proteins in S. aureus, and also had some effect in up-regulation of the expression of lukS-PV and hla in S. aureus clini- cal isolate.
出处
《中华微生物学和免疫学杂志》
CAS
CSCD
北大核心
2013年第2期91-96,共6页
Chinese Journal of Microbiology and Immunology
基金
国家自然科学基金（81271906H2002）
浙江省自然科学基金（Y2100716）
