# P-482. Colonization and Infection with Carbapenem-Resistant Organisms in Critically Ill Neonates: A Prospective Cohort Study in a Tertiary Hospital in Bangladesh

## TL;DR

This study shows that colonization with antibiotic-resistant bacteria is common in critically ill newborns and increases their risk of infection.

## Contribution

The study identifies the high prevalence and progression of CRO colonization in neonates and its link to subsequent infections.

## Key findings

- Over half of neonates were colonized with CROs at admission, and 80% of non-colonized neonates acquired CROs during their hospital stay.
- CRO colonization was associated with a 1.11 increased risk of confirmed bacterial infection.
- Klebsiella pneumoniae was the most common CRO identified in colonized neonates.

## Abstract

Antimicrobial resistance is an increasing cause of neonatal infection-related mortality. Colonization with carbapenem-resistant organisms (CRO) may precede and increase the risk for subsequent infection in neonates. In this study, we evaluated associations between CRO colonization and infectious outcomes among neonates admitted to a neonatal intensive care unit (NICU).

From July 2023 to February 2024, a prospective cohort study was conducted among neonates admitted to a tertiary hospital NICU. Neonates were assessed for CRO colonization using rectal swabs collected within 24 hours of admission, on days 3 and 7, and weekly until discharge, transfer, or death. Swabs were plated on selective agar followed by VITEK-2 identification and susceptibility testing. VITEK-2 was also used for blood and tracheal aspirate culture isolates in suspected sepsis cases. Risk ratios (RR) and other analyses were performed using Stata v15.

From July 2023 to February 2024, 423 neonates were enrolled (median age 4 days; IQR 2–8), 62% male. At enrollment, 51% (214) were colonized with CROs. Of those who were not colonized at enrollment, 80% (167/209) acquired colonization during their hospital stay (Figure 1). Among CRO-colonized neonates, 71% had Klebsiella pneumoniae (Kpn), 36% Pseudomonas aeruginosa, 36% Acinetobacter baumannii, and 31% Escherichia coli (Figure 2). Clinically suspected infections occurred in 113 (27%) neonates. Of 33 positive bacterial cultures, 10 (30%) were CROs, including Kpn (4), E. meningoseptica (2), A. baumannii (1), A. lwoffii (1), E. coli (1), and B. cepacia (1). Three clinical isolates had antibiotic susceptibility patterns matching with colonized strains; all were CR-Kpn. CRO colonization at any time point was associated with confirmed bacterial infection (RR 1.11, 95% CI 1.05–1.17).

CRO colonization was common among NICU patients and increased throughout the hospital stay. These findings highlight the urgent need of targeted prevention strategies to reduce CRO transmission and infection risk among this vulnerable population.

All Authors: No reported disclosures