Clinical, Inflammatory, and Microbiological Differences Between Preterm and Term Neonates Treated for Suspected Neonatal Infection

Neonatal infections remain a major clinical challenge, particularly in preterm infants. This single-center retrospective observational study compared clinical, maternal, perinatal, laboratory, microbiological, antimicrobial resistance, and therapeutic characteristics between 10 preterm and 42 term neonates treated for suspected neonatal infection between January 2024 and April 2026. Microbiological support for infection was identified in 48/52 neonates (92.3%). Most inflammatory indices did not differ significantly between groups. Among neonates with available procalcitonin measurements (n = 14), concentrations were higher in preterm than in term neonates (p = 0.008); however, this finding should be considered exploratory because of the limited sample size. ESBL-producing Enterobacterales were more frequently identified in preterm than in term neonates (57.1% vs. 14.8%, p = 0.037), although based on small numbers. Meropenem use was more frequent in preterm neonates (30.0% vs. 2.4%, p = 0.019), and antimicrobial treatment duration was longer (median 7.5 vs. 5.0 days, p = 0.041). These findings suggest differences in antimicrobial resistance and treatment patterns between preterm and term neonates and support continued local microbiological surveillance and antimicrobial stewardship.