Temporal Expression of Adhesion Factors and Activity of Global Regulators during Establishment of Staphylococcus aureus Nasal Colonization
Temporal Expression of Adhesion Factors and Activity of Global Regulators during Establishment of Staphylococcus aureus Nasal Colonization
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DOI：
10.1086/651619
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发表时间：
2010-05-01
影响因子：
6.4
通讯作者：
Goerke, Christiane
中科院分区：
文献类型：
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作者：
Burian, Marc;Rautenberg, Maren;Goerke, Christiane
人类病原体金黄色葡萄球菌很可能是通过对鼻子环境的调节适应，成功地在其主要储存库-鼻腔中定居。棉花鼠是研究细菌在定殖初期基因表达的一个很好的模型。为了深入了解建立定植所需的表达谱，我们通过实时定量逆转录聚合酶链式反应对从安乐死动物身上取出的棉鼠鼻腔进行了直接转录分析，这些鼻腔分别在2个人金黄色葡萄球菌分离株滴注后的第1、4或10天。在这一早期阶段，全球毒力调节系统(AGR、SAE)并不活跃，但基本的两组分调控系统WalKR似乎发挥了重要作用。因此，可以检测到walKR靶基因(sak、sceD)的高表达。与先前证明壁磷壁酸(WTA)聚合物在鼻腔定植中发挥重要作用的研究一致，我们检测到WTA生物合成基因的表达显著增加。在定殖过程的后期，表达谱转变为粘附性蛋白ClfB和ISDA的产生。这些数据强调了WTA和表面蛋白在鼻部定植中作用的时间差异，并为体内WTA生物合成的调控提供了第一个证据。
The human pathogen Staphylococcus aureus successfully colonizes its primary reservoir, the nasal cavity, most likely by regulatory adaptation to the nose environment. Cotton rats represent an excellent model for the study of bacterial gene expression in the initial phases of colonization. To gain insight into the expression profile necessary for the establishment of colonization, we performed direct transcript analysis by quantitative real-time reverse-transcription polymerase chain reaction on cotton rat noses removed from euthanized animals on days 1, 4, or 10 after instillation of 2 human S. aureus nose isolates. Global virulence regulators (agr, sae) were not active in this early phase, but the essential 2-component regulatory system WalKR seems to play an important role. Accordingly, an elevated expression of walKR target genes (sak, sceD) could be detected. In agreement with previous studies that demonstrated the essential role played by wall teichoic acid (WTA) polymers in nasal colonization, we detected a strongly increased expression of WTA-biosynthetic genes. The expression profile switched to production of the adhesive proteins ClfB and IsdA at later stages of the colonization process. These data underscore the temporal differences in the roles of WTA and surface proteins in nasal colonization, and they provide the first evidence for a regulation of WTA biosynthesis in vivo.