CLINICALLY SIGNIFICANT COAGULASE-NEGATIVE STAPHYLOCOCCI - IDENTIFICATION AND RESISTANCE PATTERNS

Coagulase-negative staphylococci (CNS) of clinical significance, isolated from 131 patients, were investigated during the period 1989-1990 in northern Norway. The staphylococci were isolated from blood cultures (68; 51·9%), vascular catheters (6), osteomyelitis foci (13), postoperative and other wounds (15), and urine samples (29). The use of Gram-positive Identification Card (Vitek) and 'Staph-zym' (Rosco) both gave a primarily correct species identification in 95% of the cases. Staphylococcus epidermidis was the predominent species (72·3%). Methicillin-resistance was found in 40 of 131 (30·5%) of all CNS and in 34 of 96 (35·4%) of S. epidermidis. Methicillin-resistant (MR) S. epidermidis strains were usually resistant to gentamicin, tetracycline, chloramphenicol and trimethoprim. MR strains were, however, less resistant to sulphonamides than methicillin-sensitive strains (10 out of 34 vs. 55 out of 62). Methicillin-resistance implied resistance to all β-lactam antibiotics, including imipenem. Among S. epidermidis, MR isolates increased from 10% in 1987 to 35·4% in 1989-1990. All strains were sensitive to vancomycin and rifampicin. © 1992.