Survey of methicillin-resistant coagulase-negative staphylococci in the hospitals of central Greece

Abstract

A sample of 450 consecutive, non-replicated coagulase-negative staphylococci (CoNS), collected from clinical specimens during the period 2000-2001 from the five major hospitals of Thessaly district (Central Greece) were investigated for resistance to methicillin. Most of the isolates had been collected in a sporadic fashion from the intensive care units and the surgical wards of the participating hospitals. The majority of the isolates (76%) were Staphylococcus epidermidis (50%), Staphylococcus haemolyticus (14.8%) and Staphylococcus hominis (11.1%). All 316 isolates (70%) were classified as resistant according to NCCLS breakpoints (MIC ≥ 0.5 mg/l); 268 (59.5%) of them were mecA-positive in a PCR-based assay. All isolates with MIC ≥ 8 mg/l carried the gene, while, only 23.8% of isolates with MIC, 0.5-4 mg/l were carriers. Only 9% of the mecA-positive isolates were found to be sensitive to various non-β-lactams, while 41.8% of the isolates were resistant to more than three antimicrobial groups apart from β-lactams. Molecular typing by PFGE showed apparent heterogeneity among isolates of each species and the absence of predominant clones. © 2001 Elsevier Science B.V. and the International Society of Chemotherapy. All rights reserved.