Objective(s): Biofilm formation is one of the most important factors in the development of infections caused by Staphylococcus aureus. In this study, the expression levels of genes responsible for biofilm formation were studied in methicillin sensitive and methicillin resistant S. aureus.Materials and Methods: A total of 100 meticillin-r...

Staphylococcus aureus is a highly virulent and successful pathogen that causes a diverse array of diseases. Recently, an increase of severe infections in healthy subjects has been observed, caused by community-associated methicillin-resistant S. aureus (CA-MRSA). The reason for enhanced CA-MRSA virulence is unclear; however, work suggests that it results from hypersecretion of agr-regulated tox...

The pattern of nucleotide substitution was examined at 2,129 orthologous loci among five genomes of Staphylococcus aureus, which included two sister pairs of closely related genomes (MW2/MSSA476 and Mu50/N315) and the more distantly related MRSA252. A total of 108 loci were unusual in lacking any synonymous differences among the five genomes; most of these were short genes encoding proteins hig...

Mastitis is one of the common diseases of dairy cattle and an inflammatory response of the mammary glands tissue. Mastitis causes considerable loss to the dairy industry. Among several bacterial pathogens that can cause mastitis, Staphylococcus aureus is probably the most lethal agent because it causes chronic and deep infection in the mammary glands that is extremely difficult to be cured. The...

Staphylococcus aureus is an important human pathogen causing nosocomial and community-acquired infections worldwide. In the characterization of this opportunistic pathogen, DNA microarray hybridization technique is used as an alternative to sequence based genotyping to obtain a comprehensive assessment on the virulence, resistance determinants, and population structure. The objective of this st...

Isogenic Staphylococcus aureus strains with different capacities to produce sigma(B) activity were analyzed for their ability to attach to fibrinogen- or fibronectin-coated surfaces or platelet-fibrin clots and to cause endocarditis in rats. In comparison to the sigma(B)-deficient strain, BB255, which harbors an rsbU mutation, both rsbU-complemented and sigma(B)-overproducing derivatives exhibi...

An elevated vancomycin MIC is associated with poor outcomes in Staphylococcus aureus bacteremia (SAB) and is reported in patients with methicillin-susceptible S. aureus (MSSA) bacteremia in the absence of vancomycin treatment. Here, using DNA microarray and phenotype analysis, we investigated the genetic predictors and accessory gene regulator (agr) function and their relationship with elevated...

Methicillin-resistant Staphylococcus aureus is an increasingly important cause of nosocomial bacterial infections worldwide. S. aureus is responsible for several pathologies, including skin infections, endocarditis, meningitis, deeptissue ulcers, and sepsis. S. aureus biofilm formation on catheters and other medical devices is a major post-operative concern, because biofilms are often the sourc...

Small colony variants (SCVs) of Staphylococcus aureus are slow-growing subpopulations that cause persistent and relapsing infections. The altered phenotype of SCV can arise from defects in menadione or hemin biosynthesis, which disrupt the electron transport chain and decrease ATP concentrations. With SCVs, virulence is altered by a decrease in exotoxin production and susceptibility to various ...

Staphylococcus epidermidis strains HB and K28 express surface proteins called Fbe or SdrG, respectively, that have sequence similarity to the clumping factors ClfA and ClfB of Staphylococcus aureus. A mutation in the fbe gene of strain HB was isolated by directed plasmid integration using the broad-host-range temperature-sensitive plasmid pG(+)Host9 (pVE6155). An internal fragment of fbe was cl...