Bischoff
Fakultäten » Medizinische Fakultät » Medizinische Mikrobiologie, Institut für » Prof. Dr. Brigitte Berger-Bächi » Bischoff
Completed research project
| Title / Titel | Microarray based analysis of the SigmaB regulon in Staphylococcus aureus | ||
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| Abstract (PDF, 14 KB) | |||
| Summary / Zusammenfassung | Staphylococcus aureus is a major human pathogen with the capacity to cause a wide spectrum of diseases. Alternative sigma factors have been shown in many bacteria to be involved in the ability to survive under extreme conditions by regulating the coordinate expression of stress response genes mediated by environmental as well as growth dependent signals. Computational analysis of the S. aureus genome suggests, beside the housekeeping transcription factor SigmaA, only one additional sigma factors, SigmaB, to be present in this organism. SigmaB was shown to be involved in the stress response to different stimuli, and the regulation of global regulators such as the staphylococcal accessory regulator (sar), its homologue sarH1 and the accessory gene regulator (agr) that have been demonstrated to be of importance for the virulence and pathogenicity of S. aureus. Additionally, SigmaB was found to influence the resistance levels to teicoplanin, and in methicillin-resistant S. aureus (MRSA) to methicillin. Although a variety of phenomena have been associated with SigmaB activity, only little is known about the genes that are controlled by this transcription factor. Especially those SigmaB-dependent genes that are involved in the development of resistance to methicillin or teicoplanin have not been identified so far. The availability of gene-chips that cover all potential open reading frames of the S. aureus genome enables us now to investigate the SigmaB regulon of this organism by the use of the microarray technology. Comparison of the transcription profiles of S. aureus strains overexpressing SigmaB activity with that of their isogenic derivatives carrying a deletion of the sigB operon should allow us to identify most of the genes that are under the control of SigmaB. Applying different kinds of stress allows us to identify, and monitor sets of genes (stimulons) that are up-regulated in S. aureus in response to the respective stimuli. | ||
| Publications / Publikationen | Giachino, P., Engelmann, S., Bischoff, M. (2001) SigmaB activity depends on RsbU in Staphylococcus aureus. J. Bacteriol. 183: 1843-52Bischoff, M., Berger-Bächi, B. (2001) Teicoplanin stress-selected mutations increasing SigmaB activity in Staphylococcus aureus. Antimicrob. Agents Chemother. 45: 1714-1720Bischoff, M., Entenza, J., Giachino, P. (2001) Influence of a functional sigB-operon on the global regulators sar and agr in Staphylococcus aureus. J. Bacteriol. 183: 5171-5179 | ||
| Keywords / Suchbegriffe | Molecular Medicine, Medical Microbiology, Staphylococcus, alternative transcription factors, regulation, SigmaB | ||
| Project leadership and contacts / Projektleitung und Kontakte |
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| Funding source(s) / Unterstützt durch |
Universität Zürich (position pursuing an academic career), Nachwuchsförderungskredit der Universität Zürich |
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| In collaboration with / In Zusammenarbeit mit |
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| Duration of Project / Projektdauer | Jan 2002 to May 2003 |