EN
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 mecX-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.