CcpA Mediates the Catabolite Repression of tst in Staphylococcus aureus

Seidl, Kati; Bischoff, Markus; Berger-Bächi, Brigitte

doi:10.1128/iai.00724-08

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Journal article

CcpA Mediates the Catabolite Repression of tst in Staphylococcus aureus

Seidl, Kati Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland
Bischoff, Markus Institute of Medical Microbiology and Hygiene, University of Saarland Hospital, Homburg/Saar, Germany
Berger-Bächi, Brigitte Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland

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Infection and Immunity. - American Society for Microbiology. - 2008, vol. 76, no. 11, p. 5093-5099

English ABSTRACT
Some clinical isolates of Staphylococcus aureus produce the superantigenic toxic shock syndrome toxin 1 (TSST-1), encoded by tst, located on pathogenicity islands. The expression of tst is complex and is influenced by environmental conditions such as pH, CO2, and glucose. We identified a putative catabolite-responsive element (cre) in the promoter regions of all known tst genes, indicating that tst transcription may be regulated by the catabolite control protein CcpA. By introducing tst genes under the control of their native promoters or tst promoter-reporter gene fusions in wild-type strain Newman, we showed that glucose was able to repress tst transcription and TSST-1 production, whereas glucose repression was abolished in the corresponding ΔccpA mutant. Stabilizing the pH ruled out a pH effect due to acid production during glucose catabolism. CcpA thus directly regulates tst transcription, linking carbohydrate utilization to virulence gene expression in S. aureus.

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