Empirical Antibiotic Treatment of Late-onset Sepsis at the NICU with Flucloxacillin and Gentamicin Instead of Vancomycin and Ceftazidime

Background: Late-onset sepsis is still a frequent cause of morbidity and mortality in the neonatal intensive care unit (NICU). Coagulase-negative staphylococci (CONS), Staphylococcus aureus and gram-negative bacteria are the main causative pathogens. Late-onset infections are responsible for a substantial part of antibiotic use in NICUs, leading to resistance and disturbance of the microbiome. Therefore, it is important to choose the empirical treatment as targeted and narrow as possible.

The current empirical therapy for suspected late-onset sepsis in our NICU is a combination of vancomycin and ceftazidime.

Objective: To investigate whether it is safe to start empirical treatment with flucloxacillin and gentamicin instead of vancomycin and ceftazidime in patients with suspected late-onset sepsis in our NICU.

Methods: A retrospective study including all positive blood cultures from January 2016 to December 2019 in the NICU Isala, Zwolle. The sensitivity of the pathogenic microorganisms for the proposed empirical treatment was determined by the antibiogram.

Results: In total, 179 positive blood cultures were analysed. CONS were the largest group (107/179, 60%), but due to the low virulence, this group was not decisive in the choice of empirical treatment. The gram-negative pathogens: Escherichia coli (22/179, 11.6%), Enterobacter cloacae (3/179, 1.7%), Klebsiella pneumonia (2/179, 1.1%), Klebsiella oxytoca (2/179, 1.1%), Serratia marcescens (2/179, 1.1%), Acinetobacter baumannii (1/179, 0.6%) and Citrobacter koseri (1/179, 0.6%), all proved highly sensitive to gentamicin. Staphylococcus aureus (27/179, 15%) and Group B streptococcus (Streptococcus agalactiae) (4/179, 1.4%) were highly sensitive to flucloxacillin.

Conclusion: It is safe and strongly recommended to change the empirical therapy for late onset-sepsis on our NICU to flucloxacillin and gentamicin.

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