Objectives: The purpose of this study was to evaluate the prevalence of methicillin-resistant Staphylococcus spp isolates with reduced susceptibility to glycopeptides in the district of Thessaly (Central Greece). Methods: A total of 160 consecutive methicillin-resistant Staphylococcus isolates (60 Staphylococcus aureus and 100 CNS), collected from clinical specimens in the University Hospital of Thessaly (October 1999-October 2000), were included. Species identification was carried out by conventional tests and the API Staph System. Methicillin-resistance was confirmed by the detection of mecA gene using PCR. Resistance to glycopeptides ( vancomycin and teicoplanin) was assessed by agar dilution method, in BHI agar, at 37 o C for 24 h incubation. Population analysis was performed in 20 random isolates. Results: All isolates were susceptible to glycopeptides according NCCLS standards. The mean value of MICs to vancomycin and to teicoplanin for S. aureus isolates were 2.6 and 3.4 Âµg/ml respectively, while 2.98 and 3.7 Âµg/ml for CNS. None of the 20 tested strains contained a sub-population of cells that grew in higher concentration of antibiotic. Conclusions: In our institution, intermediate or full resistance to glycopeptides has not been yet observed among methicillin-resistant staphylococci, despite the use of vancomycin to the treatment of infections caused by multi-resistant strains.
Full conference title:
11th European Congress of Clinical Microbiology and Infectious Diseases
- ECCMID 11th (2001)