Sepsis treatment options identified by 10-year study of microbial isolates and antibiotic susceptibility in a level-four neonatal intensive care unit.

Aim: This observational study investigated the microbiology of blood culture-positive sepsis episodes and susceptibility to empiric antibiotics in early-onset sepsis (EOS) and late-onset sepsis (LOS) in a level-four neonatal intensive care unit (NICU) from 2010 to 2019.

Methods: It was based on patient records and data that Oslo University Hospital, Norway, routinely submitted to the Norwegian Neonatal Network database. Clinical data were merged with blood culture results, including antibiotic susceptibility.

Results: We studied 5249 infants admitted to the NICU 6321 times and identified 324 positive blood cultures from 287 infants, with 30 EOS and 305 LOS episodes. Frequent causative agents for EOS were group B streptococci (33.3%), Escherichia coli (20.0%) and Staphylococcus aureus (16.7%). All were susceptible to empiric ampicillin and gentamicin. LOS was most frequently caused by coagulase-negative staphylococci (CONS) (73.8%), Staphylococcus aureus (15.7%) and Enterococci (6.9%). CONS, Staphylococcus aureus, Enterococci, Escherichia coli, Klebsiella and Enterobacter represented 91.9% of LOS episodes and were susceptible to vancomycin and cefotaxime (96.1%), vancomycin and gentamicin (97.0%) and cloxacillin and gentamicin (38.1%).

Conclusion: Empiric treatment with ampicillin and gentamicin was adequate for EOS. Combining vancomycin and gentamicin may be a safer alternative to cefotaxime for LOS, as this reduces exposure to broad-spectrum antibiotics.