Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen, which is cross-resistant to virtually all β-lactam antibiotics. MRSA strains are defined by the presence of mecA gene. The transcription of mecA can be regulated by a sensor-inducer (MecR1) and a repressor (MecI), involving a unique series of proteolytic steps. The induction of mecA by MecR1 has been described as...

Methicillin resistance in staphylococci is mediated by PBP2a, a penicillin binding protein with low affinity for beta-lactam antibiotics. The gene encoding PBP2a, mecA, is transcriptionally regulated in some clinical isolates by mecR1 and mecI, genes divergently transcribed from mecA that encode a signal transducer and repressor, respectively. The biochemical basis of MecI-mediated mecA transcr...

The presence and sequences of genes that regulate the expression of methicillin resistance was investigated in 42 isolates of Staphylococcus aureus and 102 isolates of coagulase-negative staphylococci (CNS). PCR was used to detect mecA and the regulatory genes mecR1 and mecI. In a selected group of isolates, the sequences of mecI and the mec promoter region were also determined and compared wit...

Strains of methicillin-resistant Staphylococcus aureus (MRSA) have become the most important causative agents of hospital-acquired diseases worldwide. The genetic determinant of resistance, mecA, is not a gene native to S. aureus but was acquired from an extraspecies source by an unknown mechanism. We recently identified a close homologue of this gene in isolates of Staphylococcus sciuri, a tax...

A total of 221 SIG strains were isolated from clinical samples of canine origin submitted to the Diagnostic Laboratory of the Division of Bacteriology and Molecular Biology at the Warsaw University of Life Sciences in Warsaw during the period 2006-2010. The aim of the study was to investigate the frequency of prevalence of methicillin-resistant SIG strains and to determine the MIC values of cep...

Bacillus subtilis degR, a positive regulator of the production of degradative enzymes, is negatively regulated by the competence transcription factor ComK which is overproduced in mecA null mutants. We used transposon Tn10 to search for a mutation that reduced the repression level of degR caused by a mecA mutation. A new gene exerting positive regulation on comK was obtained and designated med ...

L-selectin is a lectin-like receptor that mediates the attachment of lymphocytes to high endothelial venules (HEV) of lymph nodes during the process of lymphocyte recirculation. Two sulfated, mucin-like glycoproteins known as Sgp50/GlyCAM-1 and Sgp90/CD34 have previously been identified as HEV-associated ligands for L-selectin. These proteins were originally detected with an L-selectin/Ig chime...

Methicillin-resistant Staphylococcus aureus (MRSA) is intrinsically cross-resistant to virtually all β-lactam antibiotics. The central determinant for the MRSA phenotype is the mecA gene, whose transcriptional control may be mediated by a repressor (mecI) and a sensor/inducer (mecR1). The mecI-mecR1-mediated induction of mecA takes several hours rendering the strains phenotypically susceptible ...

AIMS The present work studied the modulatory role of methanolic extract of Cnidoscolus aconitifolius leaf (MECA) in rat model of renal dysfunction induced by chronic ethanol administration. METHODS Forty-two male Wistar albino rats weighing between 170 and 180 g were distributed into seven groups of six animals each. Some groups were pretreated with MECA (100 and 200 mg/kg) or kolaviron (KV) ...

OBJECTIVES The mec and bla systems, among other genetic factors, are critical in regulating the expression of methicillin resistance in Staphylococcus aureus. We examined by WGS a naturally occurring oxacillin-susceptible mecA-positive S. aureus isolate to identify the mechanism conferring oxacillin susceptibility. METHODS The mecA-positive oxacillin-susceptible S. aureus isolate GR2 (penicil...