Detection of methicillin resistance in hospital environmental strains of coagulase-negative staphylococci.
The aim of this study was to evaluate methicillin resistance detection methods currently used when studying coagulase-negative staphylococci (CONS). The resistance to oxacillin of 142 strains from seven species of CoNS isolated from the Intensive Care Unit environments was tested. The methods used were: disc diffusion test with cefoxitin (FOX30) and oxacillin (OX1), oxacillin agar screen test with 6 mg/l of oxacillin (MHOXA), latex test for PBP2a (LA) and detection of mecA via PCR. One hundred and one isolates were methicillin-resistant in at least one of methods used, but only 74 were mecA-positive. Of the 68 mecA-negative strains: two were positive by OX1, the LA and MHOXA methods; three by the LA and MHOXA; and 22 only by OX1 test. Most of these strains were from the novobiocin-resistant CoNS group. The results obtained for all tested strains using FOX30 showed complete concordance with the presence of the mecA gene.
Nowak
Tomasz
T
Department of Pharmaceutical Microbiology, Medical University, Lódź, Poland.
Balcerczak
Ewa
E
Mirowski
Marek
M
Szewczyk
Eligia M
EM
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D003030:Coagulase; D003428:Cross Infection / Q000382:microbiology; D006761:Hospitals; D006801:Humans; D016106:Methicillin Resistance / Q000235:genetics; D008826:Microbial Sensitivity Tests / Q000379:methods*; D010068:Oxacillin / Q000494:pharmacology*; D046915:Penicillin-Binding Proteins / Q000032:analysis; D013210:Staphylococcus / Q000187:drug effects* / Q000235:genetics*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003030:Coagulase; C487495:MecA protein, Staphylococcus epidermidis; D046915:Penicillin-Binding Proteins; D010068:Oxacillin