Adenosine, a purine nucleoside, acts as a regulatory molecule, by binding to specific G-protein-coupled A(1), A(2A), A(2B), and A(3) cell surface receptors. We have recently demonstrated that adenosine induces a differential effect on tumor and normal cells. While inhibiting in vitro tumor cell growth, it stimulates bone marrow cell proliferation. This dual activity was mediated through the A3 ...

Reports of oxacillin-susceptible mecA-positive Staphylococcus aureus strains are on the rise. Because of their susceptibility to oxacillin and cefoxitin, it is very difficult to detect them by using routine phenotypic methods. We describe two such isolates that were detected by chromogenic medium and confirmed by characterization of the mecA gene element.

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...