Fecal carriage of resistant genes among healthy infants

Abstract

Antimicrobial resistance (AMR) is a growing global health concern, with the gastrointestinal tract of neonates potentially acting as a reservoir for resistant bacteria. This study investigates the fecal carriage of resistant genes among healthy infants in Lebanon, focusing on the microbial colonization of meconium samples collected within 24 hours of birth. A total of 204 meconium samples were collected and analyzed using culture methods, antimicrobial susceptibility testing (AST), phenotypic screening for carbapenemases, and real-time PCR for detecting β-lactamase genes. Our findings revealed that 37% of the samples were culture-positive, with Enterobacter cloacae and coagulase-negative staphylococci (CONS) being the most frequently isolated bacteria. Alarmingly, we detected extended-spectrum β-lactamase (ESBL)-producing genes, including blaTEM, blaSHV, blaCTX-M, and the blaNDM carbapenemase gene, in several isolates, indicating the early acquisition of antimicrobial-resistant bacteria in newborns. Cesarean section deliveries were associated with a higher prevalence of hospital-acquired organisms such as Pseudomonas aeruginosa and Enterobacter species compared to vaginal deliveries, suggesting that delivery mode plays a significant role in early microbial colonization. This study highlights the importance of early screening for antimicrobial-resistant genes in neonates to mitigate the potential spread of multidrug-resistant organisms. Future research should expand sample sizes, employ metagenomic sequencing to capture non-culturable organisms, and consider longitudinal data to assess the persistence and long-term impact of resistant bacteria in infants.