Speciation and antibiotic susceptibility patterns of coagulase-negative staphylococci

Abstract

During a six month period, 191 isolates of coagulase-negative staphylococci from blood, urine, cerebrospinal fluid and heart valves were identified to species level and tested for antimicrobial susceptibility. Seventy-one percent of isolates wereStaphylococcus epidermidis, 8 %Staphylococcus warneri, 7 %Staphylococcus hominis, 7 %Staphylococcus haemolyticus, 4 %Staphylococcus capitis, 2 %Staphylococcus saprophyticus and 1 %Staphylococcus cohnii. Approximately 4 % of isolates were felt to be associated with infection. Overall, 18% of isolates were susceptible to penicillin G, 61 % oxacillin, 98 % cephalothin, 98 % cefamandole, 72 % cefotaxime, 95 % cefsulodin, 76 % gentamicin, 64 % clindamycin and 98 % rifampicin. All isolates were susceptible to vancomycin. Vancomycin, rifampicin, cephalothin and cefamandole showed excellent activity against oxacillin-resistant isolates. With one exception, speciation was not helpful in determining whether or not an isolate was associated with infection.