Global gene expression in Staphylococcus aureus biofilms
Global gene expression in Staphylococcus aureus biofilms
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DOI：
10.1128/jb.186.14.4665-4684.2004
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发表时间：
2004-07-01
影响因子：
3.2
通讯作者：
Smeltzer, MS
中科院分区：
文献类型：
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作者：
Beenken, KE;Dunman, PM;Smeltzer, MS
我们先前证明，在金黄色葡萄球菌临床分离株（UAMS - 1）中葡萄球菌附属调节子（sarA）的突变会导致体外形成生物膜的能力受损（K. E. 贝肯、J. S. 布莱文斯和M. S. 斯梅尔策，《感染与免疫》71:4206 - 4211，2003年）。在本报告中，我们利用基于导管的生物膜形成的小鼠模型证明，UAMS - 1的sarA突变体在体内形成生物膜的能力也降低。令人惊讶的是，UAMS - 1的ica基因座突变对体外或体内生物膜形成几乎没有影响。为了确定可能与生物膜形成和/或金黄色葡萄球菌在生物膜内持续存在所需的适应性反应相关的其他基因座，我们从在How细胞中生长的生物膜中收获的UAMS - 1中分离出总细胞RNA，并将该RNA的转录谱与从指数期和稳定期浮游培养物中分离出的RNA进行比较。比较是使用定制的Affymetrix基因芯片进行的，该芯片代表了六种金黄色葡萄球菌菌株（COL、N315、Mu50、NCTC 8325、EMRSA - 16[菌株252]和MSSA - 476）的基因组互补序列。结果证实，与浮游培养的指数期和指数后期的生活方式相比，与在生物膜内持续存在相关的固着生活方式是独特的。实际上，我们鉴定出48个基因，其在生物膜中的表达量比在两种浮游条件下的表达量至少高两倍。同样，我们鉴定出84个基因，其表达量与在两种浮游条件下的表达量相比至少被抑制了2倍。从对这些基因的分析中出现的一个主要主题是，在生物膜内持续存在需要一种适应性反应，这种反应限制了与厌氧生长条件相关的pH降低的有害影响。
We previously demonstrated that mutation of the staphylococcal accessory regulator (sarA) in a clinical isolate of Staphylococcus aureus (UAMS-1) results in an impaired capacity to form a biofilm in vitro (K. E. Beenken, J. S. Blevins, and M. S. Smeltzer, Infect. Immun. 71:4206-4211, 2003). In this report, we used a murine model of catheter-based biofilm formation to demonstrate that a UAMS-1 sarA mutant also has a reduced capacity to form a biofilm in vivo. Surprisingly, mutation of the UAMS-1 ica locus had little impact on biofilm formation in vitro or in vivo. In an effort to identify additional loci that might be relevant to biofilm formation and/or the adaptive response required for persistence of S. aureus within a biofilm, we isolated total cellular RNA from UAMS-1 harvested from a biofilm grown in a How cell and compared the transcriptional profile of this RNA to RNA isolated from both exponential- and stationary-phase planktonic cultures. Comparisons were done using a custom-made Affymetrix GeneChip representing the genomic complement of six strains of S. aureus (COL, N315, Mu50, NCTC 8325, EMRSA-16 [strain 252], and MSSA-476). The results confirm that the sessile lifestyle associated with persistence within a biofilm is distinct by comparison to the lifestyles of both the exponential and postexponential phases of planktonic culture. Indeed, we identified 48 genes in which expression was induced at least twofold in biofilms over expression under both planktonic conditions. Similarly, we identified 84 genes in which expression was repressed by a factor of at least 2 compared to expression under both planktonic conditions. A primary theme that emerged from the analysis of these genes is that persistence within a biofilm requires an adaptive response that limits the deleterious effects of the reduced pH associated with anaerobic growth conditions.