Peer Review Report For: The Changing Bacteriological Profile of Early-Onset Neonatal Bacterial Infections [version 1; peer review: 1 approved]

Introduction Early-onset neonatal bacterial infections (EONBI) are a major public health issue, causing significant neonatal mortality, especially in preterm infants. The clinical diagnosis is challenging due to nonspecific symptoms, while the bacteriological profile is shifting with increasing multidrug-resistant strains. Objective This study aimed to analyze microbiological data from EONBI cases and identify predictive factors for infections caused by resistant pathogens. Methods A retrospective study was conducted from January 2022 to December 2023 at the neonatal unit of Habib Bougatfa Maternity Center, Tunisia. Newborns with microbiologically confirmed EONBI within 48 hours of admission were included. Maternal and neonatal data were collected and analyzed, with antibiotic resistance determined by antibiogram results. Results Among 5,342 live births, 135 EONBI cases were confirmed (incidence: 25.27 per 1,000 live births). Gram-negative bacilli predominated (96.3%), notably Serratia marcescens (37.78%) and Escherichia coli (27.41%). Resistant pathogens were present in 46.66% of cases. Significant predictive factors for resistance included positive maternal screening for resistant bacteria, third trimester hospitalization, and other maternal infections. Resistant EONBI cases required longer antibiotic courses and hospital stays and were more frequently linked to complications. Conclusion The high prevalence of resistant bacterial strains in EONBI underscores the need for enhanced maternal screening and tailored antibiotic protocols to improve neonatal outcomes.