共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Jonsson IM Lindholm C Luong TT Lee CY Tarkowski A 《Microbes and infection / Institut Pasteur》2008,10(12-13):1229-1235
Septic arthritis and sepsis are common and feared complications of staphylococcal infections, and the increasing antibiotic resistance among staphylococci urge the extended research for virulence factors involved in these diseases. Staphylcoccus aureus produces a number of virulence factors controlled by several global regulatory genes including agr and sarA. MgrA is a recently identified global regulator, belonging to the SarA subfamily, which upregulates expression of several virulence factors including capsule and sortase. In addition, MgrA has been shown to regulate antibiotic resistance and decrease bacterial autolysis. In this study we have assessed the role of mgrA gene expression on induction and progression of septic arthritis and sepsis. Mice inoculated with the mgrA mutant displayed significantly less severe arthritis and showed a significantly better weight development, than wild-type inoculated mice. Importantly, all 10 mice inoculated with the mgrA mutant survived as compared to 70% mortality in the wild-type inoculated mice (p=0.003). In addition, the mgrA mutant showed significantly less bacterial persistence in kidneys as compared to the wild-type strain. We conclude that mgrA regulates virulence factors important for establishment and progression of septic arthritis and sepsis. 相似文献
3.
4.
5.
6.
7.
Transcription profiling-based identification of Staphylococcus aureus genes regulated by the agr and/or sarA loci. 总被引:2,自引:0,他引:2 下载免费PDF全文
P. M. Dunman E. Murphy S. Haney D. Palacios G. Tucker-Kellogg S. Wu E. L. Brown R. J. Zagursky D. Shlaes S. J. Projan 《Journal of bacteriology》2001,183(24):7341-7353
8.
9.
10.
11.
Valle J Toledo-Arana A Berasain C Ghigo JM Amorena B Penadés JR Lasa I 《Molecular microbiology》2003,48(4):1075-1087
12.
13.
Truong-Bolduc QC Dunman PM Strahilevitz J Projan SJ Hooper DC 《Journal of bacteriology》2005,187(7):2395-2405
14.
15.
SarA is an essential positive regulator of Staphylococcus epidermidis biofilm development 总被引:6,自引:0,他引:6
Tormo MA Martí M Valle J Manna AC Cheung AL Lasa I Penadés JR 《Journal of bacteriology》2005,187(7):2348-2356
16.
17.
18.
19.
20.
Tammy M. Rechtin Allison F. Gillaspy Maria A. Schumacher Richard G. Brennan Mark S. Smeltzer & Barry K. Hurlburt 《Molecular microbiology》1999,33(2):307-316
Staphylococcus aureus is a potent human pathogen that expresses a large number of virulence factors in a temporally regulated fashion. Two pleiotropically acting regulatory loci were identified in previous mutational studies. The agr locus comprises two operons that express a quorum-sensing system from the P2 promoter and a regulatory RNA molecule from the P3 promoter. The sar locus encodes a DNA-binding protein that activates the expression of both agr operons. We have cloned the sarA gene, expressed SarA in Escherichia coli and purified the recombinant protein to apparent homogeneity. The purified protein was found to be dimeric in the presence and absence of DNA and to consist mostly of alpha-helices. DNase I footprinting of SarA on the putative regulatory region cis to the agr promoters revealed three high-affinity binding sites composed of two half-sites each. Quantitative electrophoretic mobility shift assays (EMSAs) were used to derive equilibrium binding constants (KD) for the interaction of SarA with these binding sites. An unusual ladder banding pattern was observed in EMSA with a large DNA fragment including all three binding sites. Our data indicate that SarA regulation of the agr operons involves binding to multiple half-sites and may involve other sites located downstream of the promoters. 相似文献