A comparative assessment of bacterial load and other high-risk factors of necrotizing enterocolitis among neonates in Bangladesh

Abstract

Necrotizing enterocolitis (NEC) is a serious inflammatory disease of the gastrointestinal tract that mainly affects preterm, low birth weighted neonates and remains an important cause of neonatal morbidity and mortality. In Bangladesh, evidence describing both intestinal bacterial burden and clinical high risk factors in NEC is still limited. This case-control study assessed bacterial load, different bacterial detection, and high risk factors among neonates in Bangladesh. A gender and gestational age matched case-control study was conducted at Ad-din Medical College Hospital, Bangladesh. The study population consisted of 66 preterm neonates (gestational age 28 to 36 weeks, birth weight up to 1.5 kg), including 33 NEC cases and 33 non-NEC controls. NEC cases were identified during sample collection based on key clinical features, including a positive occult blood test (OBT), abdominal distension, and the presence of bubble gas. Stool specimens were cultured on selective and differential media to measure bacterial load (CFU/ml) and to identify presumptive organisms based on colony morphology. PCR was performed to identify Escherichia coli and Klebsiella pneumoniae; PCR for other suspected organisms could not be performed due to unavailability of primers. To assess the significance of crude and adjusted odds ratio (aOR) of clinical relevance, Fisher’s test and Chi-square test were applied. Compared with NEC cases, controls showed a higher overall bacterial load, with a mean load of 1.25 × 107 CFU/ml in NEC and 2.21 × 107 CFU/ml in controls, representing an approximately 1.8 times higher load in the control group. However, PCR based detection identified E. coli and K. pneumoniae more frequently in NEC cases than in non-NEC. Growth on selective media suggested organisms such as Staphylococcus epidermidis, Staphylococcus saprophyticus, and Pseudomonas aeruginosa, along with several unidentified isolates. Several factors were analyzed including congenital heart disease, cardiogenic shock sepsis, formula feeding, breastfeeding, seizures and blood transfusion, only both type feeding demonstrated statistically significant difference between two groups (aOR: 0.8254; 95% CI: 0.2280-2.719; p < 0.05). Moreover, multidrug resistance was common in K. pneumoniae and E. coli isolates, and E. coli showed higher antimicrobial resistance. Our findings provide insight into clinical and microbiological parameters that may be useful for characterizing NEC. Because NEC is a complex inflammatory condition, further studies examining how multiple risk factors interact are needed to help lower the risk and impact of this devastating disease.