Possible role of sarA in dehydroepiandrosterone-mediated increase in Staphylococcus aureus resistance to vancomycin.
BACKGROUND
Dehydroepiandrosterone (DHEA), a steroid present throughout life, can induce an increase in resistance to vancomycin in methicillin-sensitive and methicillin-resistant clinical isolates of Staphylococcus aureus.


METHODS
The in vitro effect of DHEA on vancomycin killing of S. aureus with mutations in sarA and/or agr was determined by standard microtiter protocols and time to kill determinations.


RESULTS
Of the isolates tested, the strain with a deletion in sarAderived from a DHEA- responsive parent was not protected from vancomycin killing by DHEA. However, DHEA significantly (p < 0.01) slowed the rate of vancomycin killing of sarA-.


CONCLUSIONS
These data indicate that sarA may play a role in DHEA-mediated protection from vancomycin killing of S. aureus.
Plotkin
Balbina J
BJ
Department of Microbiology and Immunology, Midwestern University, Downers Grove, Ill 60515, USA. Bplotk@Midwestern.edu
Konaklieva
Monika
M
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D003687:Dehydroepiandrosterone / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics; D015534:Trans-Activators / Q000172:deficiency / Q000235:genetics*; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance / Q000187:drug effects* / Q000235:genetics
C095698:Agr protein, Staphylococcus aureus; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C088021:SarA protein, bacterial; D015534:Trans-Activators; D003687:Dehydroepiandrosterone; D014640:Vancomycin