Coagulase-negative Staphylococci in a major Danish university hospital: diversity in antibiotic susceptibility between wards

Over a one-year period, all coagulase-negative staphylococci (CoNS) from blood cultures, cerebrospinal fluids and peritoneal effluents from patients in a major Danish university hospital were investigated for susceptibility to penicillin G; methicillin; gentamicin; netilmicin; amikacin; erythromycin; clindamycin; fusidic acid; rifampicin; tetracycline; chloramphenicol; ciprofloxacin; teicoplanin; and vancomycin. Among the CoNS-isolates, 56% were resistant to methicillin, 51% to gentamicin, 28% to ciprofloxacin, and 5% to teicoplanin. Blood culture CoNS-isolates from patients with a central venous catheter (CVC) were more often resistant to various antibiotics compared to CoNS-isolates from patients without a CVC, e.g. methicillin (72% vs 21%), gentamicin (65% vs 22%) (p<0.00000001). Great diversity in antibiotic resistance between the wards was found; methicillin resistance (in most cases multiple antibiotic resistance) was in particular associated with consumption of broad-spectrum beta-lactams, quinolones, and total antibiotic consumption in a ward. Thus, the antibiotic policy of a ward is an important factor for antibiotic resistance among CoNS.