Characterization of aerobic Gram-negative gut microflora of mother baby pairs in normal and caesarean section deliveries.

Abstract

Background: The human gut microbiota plays a crucial role in maintaining host health, and various factors, including mode of delivery at birth influence its composition. This study aimed to comprehensively characterize the cultivable aerobic gram-negative gut microflora in mother-baby pairs born through vaginal and cesarean section (C section) deliveries, with a focus on understanding the impact of delivery mode on neonatal gut microbiota. Methods: The study involved processing fecal specimens obtained from mother-baby pairs. Sample verification and documentation were performed. The samples were processed by plating them on MacConkey and ChromAgar plates. Bacterial colonies were identified by Gram staining, hanging drop motility assay, and biochemical tests along with automated identification for few of the unidentified organisms. End point PCR were performed for the detection of antibiotic resistant genes in all the isolates. Results: Thirty mother-baby pairs (15 each from C-section and vaginal delivery) and their baby's follow-up (10 C-section, 5 vaginal) specimens were screened for cultivable aerobic Gram-negative bacteria isolation and identification. A total of 47 E. coli and 29 K. pneumoniae isolates were obtained. Seven of 32 mother’s E. coli isolates showed at least one antibiotic resistant gene (ARG) while 10 had multiple ARGs. Eleven of 16 mother’s K. pneumoniae isolates, showed at least one ARG while only one of them had multiple ARGs. Two of 15 baby’s E. coli isolates showed at least one ARG while none of them had multiple ARG. 4 of 13 baby’s K. pneumoniae isolates showed at least one ARG while 5 of them had multiple ARGs. Conclusion: In conclusion, the results from this study shed light on the presence, distribution, and characteristics of aerobic Gram-negative bacteria, particularly E. coli and K. pneumoniae, in fecal specimens of mother-baby pairs. The study demonstrated that both C-section and vaginal delivery cases harbour these bacteria, with E. coli being more in number. However, K. pneumoniae showed a higher occurrence in C-section cases. Genotypic assays revealed that the C-section group exhibited a higher number of ARG associated with beta-lactam antibiotics as compared to the vaginal delivery group.