Background: Activity of norA efflux pump is one of the antibiotic resistance mechanisms in ciprofloxacin resistant Staphylococcus aureus. In this study, the effect of Artemisia ciniformis extract on reducing the expression of norA efflux pumps gene in ciprofloxacin-resistant Staphylococcus aureus isolates was studied. Materials and Methods: Ciprofloxacin resistant S. aureus isolates, were trea...

staphylococcus aureus causes a wide variety of infections worldwide. methicillin-resistant s. aureus is one of most common causes of nosocomial and community acquired infections. the fluoroquinolones are an important class of antibiotics that used to treat infections caused by s. aureus. today, a significant increase in the rate of ciprofloxacin resistance in methicillin-resistant s. aureus str...

The NorA efflux pump considered as one of the contributors to antibiotic resistance in Staphylococcus aureus strains. One of the challenges of the researchers is finding natural plant compounds with the ability to inhibit the pumps. The aim of this study was to investigate the inhibitory effect of thyme (Thymus vulgaris) extract on NorA efflux pump in ciprofloxacin-resistant strains of S. aureu...

Emerging drug resistance in clinical isolates of Staphylococcus aureus might be implicated to the overexpression of NorA efflux pump which is capable of extruding numerous structurally diverse compounds. However, NorA efflux pump is considered as a potential drug target for the development of efflux pump inhibitors. In the present study, NorA model was constructed based on the crystal structure...

OBJECTIVES To delineate the role of capsaicin (8-methyl-N-vanillyl-6-nonenamide) as an inhibitor of the NorA efflux pump and its impact on invasion of macrophages by Staphylococcus aureus. METHODS Capsaicin in combination with ciprofloxacin was tested for activity against S. aureus SA-1199B (NorA overproducing), SA-1199 (wild-type) and SA-K1758 (norA knockout). The role of NorA in the intrace...

Staphylococcus aureus causes a wide variety of infections worldwide. Methicillin-resistant S. aureus is one of most common causes of nosocomial and community acquired infections. The fluoroquinolones are an important class of antibiotics that used to treat infections caused by S. aureus. Today, a significant increase in the rate of ciprofloxacin resistance in methicillin-resistant S. aureus str...

We hypothesized that multidrug resistance efflux pumps (MDRs) may be contributing to the drug resistance of enterococci. We recently identified potential MDR-encoding genes in the Enterococcus faecalis V583 genome. Among the putative MDRs, we found a gene that encodes a NorA homolog and have characterized this enterococcal MDR in the present study. A mutant from which the enterococcal NorA homo...

NorA, a multidrug efflux pump in Staphylococcus aureus, protects the cell from multiple drugs, including quinolones. The flqB mutation (T-->G) in the 5' untranslated region upstream of norA causes norA overexpression of 4.9-fold in cis, as measured in norA::blaZ fusions. The transcriptional initiation site of norA was unchanged in mutant and wild-type strains, but the half-life of norA mRNA was...