Clinical and Molecular Epidemiologic Characteristics of Coagulase-Negative Staphylococcal Bloodstream Infections in Intensive Care Neonates
This study aimed to determine clinical characteristics of coagulase-negative staphylococcal (CoNS) sepsis in neonates, to assess the molecular epidemiology and biofilm forming properties of isolated strains, and to assess antibiotic susceptibility of clonal compared with incidentally occurring strains.Methods:
We performed a retrospective study on late-onset CoNS sepsis in infants in the neonatal intensive care unit of a Dutch university hospital in 2003. CoNS isolates were genotyped by restriction fragment end labeling and pulsed-field gel electrophoresis. Resistance profiles, biofilm production, and the presence of mecA and icaA were determined.Results:
Twenty-six percent of all 339 infants developed late-onset sepsis, 66% of these with CoNS sepsis. Eighty-six percent of all CoNS sepsis occurred in very low birth weight infants. Sixty-six CoNS strains were isolated. In multivariate analysis, small for gestational age and prolonged hospitalization were associated with CoNS sepsis. Among 3 restriction fragment end labeling clusters, we found 1 large cluster comprising 32% of the isolates. Biofilm producing Staphylococcus epidermidis were more frequently icaA positive than nonbiofilm formers (74% vs. 12%; P < 0.001). In other species, this association was not found. Nearly all isolates were resistant to antibiotics. MecA was present in 87% of the isolates. Multiresistance occurred in 77% of all strains and in 73% of clustered strains. There was significantly less multiresistance among the largest cluster.Conclusions:
Small for gestational age and prolonged hospitalization were associated with CoNS sepsis. The icaA gene is a predictor for biofilm formation in S. epidermidis, but not in other species. Multiresistance is not associated with clonality.