Antibiotic susceptibility of staphylococci isolated in blood cultures in relation to antibiotic consumption in hospital wards

A total of 510 isolates of Micrococcaceae, 500 of staphylococci and 10 micr ococci, detected in 485 (3.3%) of 14,860 consecutive blood cultures obtaine d from patients at a Swedish university hospital and 2 local hospitals were identified to species level and investigated for antibiotic susceptibility . The 5 most frequently isolated species were Staphylococcus epidermidis (5 4.8%), S. aureus (28.0%), S. hominis (3.4%), S. warneri (3.2%) and S. haemo lyticus (2.8%). All isolates of S. aureus were oxacillin sensitive. Great d iversity in antibiotic resistance among coagulase negative staphylococci be tween hospitals and different ward units in the university hospital was obs erved. The frequency of antimicrobial resistance among S. epidermidis corre lated with the antibiotic consumption at different ward units, in particula r for ciprofloxacin (p < 0.001) and co-trimoxazole (p < 0.004). The study e mphasizes the importance of monitoring antibiotic consumption and resistanc e patterns of nosocomial staphylococci in order to avoid emergence and spre ad of multi-resistant bacteria within the hospital environment.