EVALUATION OF STAPHYLOCOCCI ISOLATED FROM A BLOOD CULTURE SYSTEM (COLORBACT(R))

During a one-year period, all blood cultures positive for staphylococc i from two of the smaller Danish counties with non-university hospital s only were evaluated. The isolates were speciated and coagulase-negat ive staphylococci (CoNS) were biotyped. Furtermore, antibiogram, phage typing and lectin typing were performed for all isolates. Clinical in formation was obtained by telephone, and before any bacteriological id entification was performed, a preliminary judgment was made as to whet her the positive blood culture was of clinical significance. A total o f 3,500 blood cultures were evaluated and 426 (12.2%) were positive. O ne hundred and sixty blood cultures from 137 patients contained staphy lococci; 36 of these patients had a pure culture of Staphylococcus aur eus. One hundred and twenty-four CoNS were found and identified as S. epidermidis (81), S. hominis (19), S. haemolyticus (8), S. simulans (1 ), and Micrococcus species (3), and another 12 staphylococcal isolates which could not be identified to species level. A total of 35 patient s had mixed cultures, including 6 with S. aureus as one of the isolate s and 15 with mixed CoNS. Clinical relevance was estimated in 90% of c ases where the later bacterial identification showed S. aureus, wherea s clinical relevance was absent in the majority of cases including CoN S. Methicillin and gentamicin resistance was absent among S. aureus, b ut frequent among CoNS, especially S. epidermidis, where 40% were resi stant to methicillin and 30% to gentamicin.