A lack of sigma(B) activity reduces methicillin resistance in heterogeneous Staphylococcus epidermidis 1057, whereas inactivation of the anti-sigma factor RsbW switched the phenotype to homogeneous expression of resistance. Oxacillin induction of mecA transcription is reduced in a sigma(B)-negative strain. However, mecA is not involved in the switch of expression phenotype.

The mecA gene was lost in 36 (14.4%) of 250 methicillin-resistant Staphylococcus aureus isolates after 2 years of storage at -80 degrees C with the Microbank system (Pro-lab Diagnostics, Austin, Tex.). Further analysis of 35 of these isolates confirmed loss of the mecA gene in 32 isolates. This finding has important implications for the management of strain collections.

The aim of this study was to compare a real-time PCR assay, with a conventional culture/PCR method, to detect S. aureus, mecA and Panton-Valentine Leukocidin (PVL) genes in animals and retail meat, using a two-step selective enrichment protocol. A total of 234 samples were examined (77 animal nasal swabs, 112 retail raw meat, and 45 deli meat). The multiplex real-time PCR targeted the genes: nu...

During the process of lymphocyte recirculation, lymphocytes bind via L-selectin to sulfated sialyl-Lewisx (sLex)-containing carbohydrate ligands expressed on the surface of high endothelial venules (HEV). We have examined the expression of sLex on HEV using a panel of mAbs specific for sLex and sLex-related structures, and have examined the function of different sLex-bearing structures using an...

Abstract Introduction/Objective Parenteral therapy for invasive staphylococcal infections often comprises lipo/glycopeptides methicillin resistant (MR) organisms, with extended spectrum penicillins reserved those confirmed as susceptible (MS). While phenotypic antimicrobial susceptibility testing (AST) using cefoxitin has high accuracy differentiating MR/MS S. aureus, the same, simple approach ...

Sampling animals for carriage of meticillin-resistant, coagulase-positive staphylococci (MRCoPS), considered zoonotic pathogens, can be challenging and time-consuming. Developing methods to identify mecA from non-invasive samples, e.g., faeces, would benefit AMR surveillance management MRS carrier animals. This study aimed distinguish carriers non-carriers faecal samples using quantitative poly...

An advanced methicillin-resistant Staphylococcus aureus (MRSA) detection PCR approach targeting SCCmec-orfX along with mecA and mecC was evaluated for S. aureus and coagulase-negative staphylococci. The possession of mecA and/or mecC was correctly confirmed in all cases. All methicillin-susceptible S. aureus strains (n = 98; including staphylococcal cassette chromosome mec element [SCCmec] remn...

Recently, we have demonstrated that the cognate regulatory locus of the mecA gene in methicillin-resistant Staphylococcus aureus (MRSA) is in fact a three-component system containing the novel mecR2 gene coding for an antirepressor. MecR2 interacts with the repressor MecI, disturbing its binding to the mecA promoter and fostering its proteolysis. Here, we engineered a point mutation in the puta...

The mitochondria-ER cortex anchor (MECA) is required for proper mitochondrial distribution and functions by tethering mitochondria to the plasma membrane. The core component of MECA is the multidomain protein Num1, which assembles into clusters at the cell cortex. We show Num1 adopts an extended, polarized conformation. Its N-terminal coiled-coil domain (Num1CC) is proximal to mitochondria, and...

The essential oil (EO) from Salvia sclarea was shown to increase the susceptibility of methicillin resistant Staphylococcus epidermidis (MRSE) isolates to oxacillin. The purpose of this study was to investigate the effect of EO from S. sclarea on expression of mecA gene of MRSE carrying different types of staphylococcal chromosomal cassette (SCCmec) and to evaluate potential synergistic effect ...