Exploring the incidence and gut microbiota of suspected Necrotizing Enterocolitis (NEC) in Neonates in Bangladesh: a case-control study

Abstract

"Necrotizing enterocolitis (NEC) is one of the most common and devastating intestinal inflammatory diseases in preterm infants with very low birth weights (less than 1,500 gram). Although the exact mechanisms that cause NEC remain elusive, an underlying relationship of the gut microbiome with NEC has been suggested. This study aims to compare and characterize the clinical and demographic data, gut bacteria and their antibiotic resistance pattern in suspected NEC vs. non-NEC infants. To the best of our knowledge, this is the first of this kind of study conducted in Bangladesh.

Stool samples were collected from thirty suspected NEC cases and thirty age- and sex-matched healthy controls admitted to the Ad-din Medical College Hospital. Samples were processed by traditional plating methods using both selective and non-selective culture media. Each morphologically distinct colony was isolated, and identified by the MALDI-TOF MS technique and confirmed using VITEK. The antibiogram of the identified bacteria against twelve antibiotics was performed using the disc diffusion method.

Few clinical and demographic differences were found between suspected cases and controls, however it was found that suspected NEC cases saw more abdominal changes, a higher incidence of vomiting and had almost twice as much antibiotics prescribed when compared with the control group. A higher load of bacteria of a magnitude of almost 4 times was found in the control group compared to the suspected cases in all selective and differential media. While Escherichia coli and Klebsiella pneumoniae were commonly observed in both cases and controls, the suspected NEC group showed the presence of unique bacterial species such as Serratia marcescens, Morganella morganii, Kocuria kristinae, Streptococcus thoraltensis and Enteriobacter clocae. Bacteria isolated from suspected NEC case neonates showed 100% resistance to the antibiotics Vacnomycin and Linezolid and species of K. pneumoniae isolated from the suspected NEC case neonates were resistant to more drugs than those isolated from the controls. Moreover, species of M. morganii were resistant against more than 50% of the antibiotics tested. "