A DNA hybridization method with an enzyme-labeled oligonucleotide probe (mecA-ELONP) was developed to detect the methicillin-resistant gene (mecA) in methicillin-resistant Staphylococcus aureus. For rapid identification, bacterial colonies were transferred from agar plates directly onto nylon membranes. Lysis of cells, denaturation of DNA, and hybridization were performed on the membranes. Thes...

Community-type Staphylococcus aureus strains that are positive for mecA and PBP2a but appear phenotypically susceptible to oxacillin are increasingly reported worldwide. Four S. aureus clinical isolates carrying the mecA gene with oxacillin MICs of <2 microg/ml were tested for oxacillin efficiency by population analyses and experimental thigh infections. These isolates harbored staphylococcal c...

Staphylococci that acquire the mecA gene are usually resistant to beta-lactam antibiotics (methicillin or oxacillin resistance). mecA encodes a penicillin-binding protein (PBP 2a) that has a reduced affinity for beta-lactams. In some isolates with methicillin or oxacillin resistance, only a small proportion (< or =0.1%) of the population expresses resistance to > or =10 microg of oxacillin per ...

Objectives: Vancomycin use for neonatal coagulase-negative staphylococci (CoNS) sepsis is based on a high CoNS carriage rate of mecA, encoding penicillin-binding protein (PBP)-2a, with low affinity for, and associated with resistance to, b-lactam antibiotics. The relationship between mecA gene carriage, phenotypic expression of the gene by PBP-2a production and in vitro resistance to the b-lact...

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...

BACKGROUND Staphylococcus aureus, an important human pathogen is one of the main causative agents of nosocomial infection. Virulence genes play a major role in the pathogenicity of this agent and its infections. Methicillin-Resistant Staphylococcus aureus (MRSA) isolates are major challenge among infectious agents that can cause severe infections and mortality. Methicillin-resistant S. aureus p...

BACKGROUND We aimed to investigate the prevalence of disinfectant resistance genes (qacA/qacB,qacC) and the aminoglycosides resistance genes [(aac(6')aph(2''),aph(3')-IIIa,ant(4')-Ia)] in both S. aureus and coagulase-negative staphylococcal strains (CoNS) isolated from surgical site infections. MATERIAL AND METHODS Totally, 130 staphylococcal strains isolated from surgical site infections bet...

Staphylococcus lugdunensis is a rare cause of severe infections and clinical manifestations are similar to those related to S. aureus infection. We describe a hospital-acquired bacteremia due to methicillin-resistant Staphylococcus lugdunensis, misidentified as methicillin-resistant S. aureus. The oxacillin MIC was 16 µg/mL and the mecA gene and SCCmec type V were determined by PCR. Although tr...