Bacterial etiology and antibiotic sensitivity patterns in late-onset neonatal blood infection: A 6-year retrospective study

Introduction: The incidence and etiology of neonatal bloodstream infections vary globally. Early appropriate antibiotic therapy is crucial. An empiric antibiotic choice should be driven by accurate knowledge of the local spectrum of pathogens and susceptibilities. Methodology: A retrospective observational study was conducted on neonates born at local tertiary center from January 1, 2013, to December 31, 2018, with late-onset bloodstream infection (LBSI). Trends of causative organisms and antibiotic susceptibilities were analyzed. Results: A total of 696 LBSI occurred in 469 neonates. Overall incidence over the 6 years was 122/1000 admissions. The median time to LBSI was 13 days of life. Majority of infections occurred in infants <32 weeks. About 75.9% were caused by Gram-positive and the rest by Gram-negative bacteria. The most common organism was coagulase-negative staphylococcus (CoNS) which showed an increase in resistance to amikacin over time, but with stable sensitivity patterns to teicoplanin. Klebsiella and Escherichia coli were the most common Gram-negative organisms. There was improving sensitivity to cephalosporin in Klebsiella species. Sixteen percent of Gram-negative isolates were extended spectrum beta-lactamase (ESBL) producing. Majority of the Gram-negative bacteria including ESBL-producing strains remained sensitive to amikacin. An empiric antibiotic combination of teicoplanin and amikacin was appropriate to cover the majority of LBSIs. Conclusions: The majority of late-onset neonatal bloodstream infections in this study cohort were caused by Gram-positive organisms of which CoNS was the most common. The empiric antibiotic choices for LBSI on our unit seem appropriate based on the data. In units where the organism and susceptibility patterns are similar, the same antibiotic choices may be justified.