[Coagulase-negative staphylococci--problem bacteria in the hospital. Identification and resistance status]

Abstract

131 coagulase-negative staphylococci (CNS) of clinical significance were investigated during the period 1989-1990 in Northern Norway. The staphylococci were isolated from blood cultures (68/131, 51.9 per cent), vascular catheters (6/131), patients with osteomyelitis (13/131), postoperative and other wounds (15/131) and urinary tract infections (29/131). The staphylococci were mostly from hospitalized patients (114/131). Vitek's GPI and Rosco's Staph-zym both gave a primarily correct identification in 95 per cent of the cases. S epidermidis was the predominant species (96/131; 73.3 per cent). Methicillin resistance (MR) was found in 30.5 per cent (40/131) of all CNS and in 35.4 per cent (34/96) of S epidermidis. Methicillin resistant S epidermidis isolates were usually resistant to gentamicin (25/34, 73.5 per cent). S haemolyticus was the most resistant species with MR in 5/7 strains. MR imply resistance to all beta-lactam antibiotics, including imipenem. Among S epidermidis, an increased MR from 10 per cent in 1987 to 35.4 per cent in 1989-1990 was observed. All strains were sensitive to vancomycin and rifampicin.