CHARACTERIZATION OF COAGULASE-NEGATIVE STAPHYLOCOCCI CAUSING NOSOCOMIAL INFECTIONS IN PRETERM INFANTS

The species spectrum, antibiotic susceptibility, and genomic profile o f coagulase-negative staphylococci (CNS) isolated from infected preter m infants were compared with those obtained in CNS from nursery person nel. Staphylococcus epidermidis was the predominant species in the 66 investigated preterm infants (171 isolates), accounting for 64% of all isolates. A high proportion of Staphylococcus haemolyticus (32%) coul d be detected. In contrast to the results in patients, the spectrum in nursery personnel was broad and included more species of CNS. All iso lates of CNS from preterm infants demonstrated a low rate of susceptib ility to the beta-lactam antibiotics (2% sensitivity to penicillin and 6% sensitivity to oxacillin). Sensitivity to gentamicin (9%) was also rare. An unexpected observation was susceptibility to teicoplanin in only 70% of all CNS isolated from patients due to the high proportion of Staphylococcus haemolyticus. Analysis of the genomic profile of 33 isolates of Staphylococcus haemolyticus by pulsed-field gel electropho resis revealed a relationship between the strains. An outbreak of one particular strain of Staphylococcus haemolyticus in the neonatal inten sive care unit investigated can therefore not be excluded.