Profile, predictors, and outcomes of multidrug-resistant neonatal sepsis: Insights from a level III NICU in Kolkata, Eastern India

INTRODUCTION: Multidrug-resistant organism (MDRO)-associated neonatal sepsis is an emerging concern in low- and middle-income countries; however, region-specific microbiological and clinical data from Eastern India remain limited. This study aimed to characterise the bacteriological profile, antimicrobial resistance patterns, prevalence, clinical predictors, and outcomes of MDRO-associated sepsis in a Level III neonatal intensive care unit (NICU). METHODS: We conducted a retrospective cohort study of neonates (0-28 days) with blood culture-proven bacterial sepsis admitted to a Level III NICU in Kolkata between January and December 2025. Organisms were identified using standard microbiological techniques, and antimicrobial susceptibility testing was performed according to the Clinical and Laboratory Standards Institute guidelines (2023). MDROs were defined as non-susceptibility to ≥1 agent in ≥3 antimicrobial categories. Independent predictors were identified using multivariable logistic regression; survival was analysed using Kaplan-Meier and Cox regression. RESULTS: Prevalence of culture-proven bacterial sepsis was 27.8%. Compared with culture-negative suspected sepsis, culture-positive neonates had significantly lower birth weight, higher prematurity and outborn rates, greater need for invasive support, longer NICU stay, and higher mortality. Among culture-positives (n = 97), 54.6% had late-onset sepsis, 67.0% were outborn, and 81.4% were preterm. Gram-negative organisms predominated (78.4%), mainly Klebsiella pneumoniae (30.9%) and Acinetobacter baumannii (24.7%). Overall, 42.3% of isolates were multidrug-resistant, with the highest rate in Acinetobacter baumannii (68.4%). Independent predictors of MDRO sepsis were birth weight 1500-2499 g, outborn status, premature rupture of membranes >18 h, and NICU stay ≥7 days. Mortality was higher in MDRO than non-MDRO sepsis (53·7% vs 26·8%), with an approximately two-fold increased risk of death (hazard ratio 2·11, 95% CI 1·05-4·25; log-rank p = 0·003). CONCLUSIONS: MDROs accounted for a substantial proportion of neonatal sepsis in Eastern India, driven largely by Gram-negative organisms, and are associated with high mortality. Recognition of key predictors provides opportunities for strengthened infection prevention, antimicrobial stewardship, and region-specific empirical antibiotic policies.