Project name: Staphylococcus aureus

Description: In the present study we analyzed the response of S. aureus to mupirocin, the drug of choice for nasal decolonization of S. aureus. Mupirocin selectively inhibits the bacterial isoleucyl-tRNA synthetase (IleRSs) leading to the accumulation of uncharged isoleucyl-tRNA and hence (p)ppGpp. The latter is a signal for the induction of the stringent response, an important global transcriptional and translational control mechanism that allows bacteria to adapt to nutritional deprivation.To identify proteins with an altered synthesis pattern in response to mupirocin treatment we used the highly sensitive 2-dimensional gel electrophoresis technique in combination with mass spectrometry. Obtained results were complemented by DNA-microarray, Northern blot and metabolome analysis. Whereas expression of genes involved in nucleotide biosynthesis, DNA metabolism, energy metabolism and translation was significantly down-regulated, expression of the isoleucyl-tRNA synthetase, the branched chain amino acids pathway, genes with functions in oxidative stress resistance (ahpC, katA), putative roles in stress protection (SACOL1759, SACOL2131, SACOL0815) and transport processes was increased. Of particular interest were the differences in the transcription of genes encoding virulence associated regulators (i.e. arlRS, saeRS, sarA, sarR, sarS) as well as genes directly involved in the virulence of S. aureus (i.e. fnbA, epiE, epiG, seb). In the present study we analyzed the response of S. aureus to mupirocin, the drug of choice for nasal decolonization of S. aureus. Mupirocin selectively inhibits the bacterial isoleucyl-tRNA synthetase (IleRSs) leading to the accumulation of uncharged isoleucyl-tRNA and hence (p)ppGpp. The latter is a signal for the induction of the stringent response, an important global transcriptional and translational control mechanism that allows bacteria to adapt to nutritional deprivation.Overall design: In total four independent hybridization experiments with each representing a biological replicate including a control and a treated sample were carried out. To account for the dye bias two of the four replicates were dye swapped.

Data type: Transcriptome or Gene expression

Sample scope: Multiisolate

Relevance: Medical

Release date: 2012-01-23

Last updated: 2011-07-18