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Non-Invasive Model of Neuropathogenic Escherichia coli Infection in the Neonatal Rat
Published on: October 29, 2014
Prenatal versus Postnatal Initial Colonization of Healthy Neonates' Colon Ecosystem by the Enterobacterium
Mohammad Al-Balawi1, Fatthy Mohamed Morsy1,2
1Biology Department, Faculty of Science, Taibah Universitygrid.412892.4, Medina, Saudi Arabia.
Insights
Escherichia coli (E. coli) does not colonize the meconium of healthy newborns. Initial E. coli colonization occurs postnatally, suggesting meconium may protect the infant gut from infection.
Area of Science:
- Microbiology
- Neonatal Health
- Gut Microbiome
Background:
- The neonatal gut microbiome is crucial for infant health.
- Early colonization by bacteria like Escherichia coli (E. coli) establishes this ecosystem.
- Understanding the timing of initial colonization is key to infant health.
Purpose of the Study:
- To investigate the presence of viable culturable E. coli in neonatal meconium versus subsequent stool.
- To differentiate between prenatal and postnatal colonization of the colon by E. coli in healthy neonates.
- To explore the role of meconium in early gut microbial colonization.
Main Methods:
- E. coli detection in meconium and stool using eosin-methylene blue (EMB) agar.
- Morphological and biochemical characterization of isolates.
- Phylogenetic analysis of 16S rRNA gene sequences.
Main Results:
- Viable culturable E. coli was undetectable in the meconium of all healthy neonates studied.
- Neonates delivered via cesarean section showed no E. coli colonization by day three.
- E. coli colonization was observed by the second day in vaginally delivered neonates, suggesting acquisition during birth.
Conclusions:
- The meconium microbiome in healthy neonates appears non-viable, potentially due to antimicrobial properties.
- Initial colonization of the colon by E. coli is a postnatal event.
- Prenatal meconium may play a protective role against gut infections during delivery.
Abstract:
The human colon is a microbial ecosystem whose initial bacterial colonization in neonates is an important step in establishing a beneficial microbiota for the body's health. This study investigated the occurrence of viable culturable Escherichia coli in first-day meconium versus subsequent days' stool to explore the prenatal versus postnatal initial colonization of the colon by E. coli in healthy neonates. E. coli occurrence was investigated on eosin-methylene blue (EMB) agar, followed by morphological and biochemical characterizations and phylogenetic analysis of 16S rRNA-encoding gene sequences. Viable culturable E. coli was not detected in meconium of healthy male or female neonates delivered either vaginally or by cesarean section. Neonates delivered surgically also showed no E. coli colonization on the second and third days, confirming postnatal colonization of the colon by this enterobacterium. E. coli's initial colonization in the colon of neonates delivered vaginally occurred on the second day, which can be attributed to inoculation from the vaginal canal during delivery and, in comparison to the colonization in neonates delivered surgically, leads to the inference that the bacterium is not originally found in meconium. This study suggests no viability of the meconium microbiome in healthy neonates, possibly due to antimicrobial action in the prenatal colon's meconium protecting babies' gut from infection during delivery. IMPORTANCE The results of this study suggest that the initial postnatal colonization of neonates' colon by beneficial bacteria is a naturally controlled process in which the prenatal colon's meconium might play a role in protecting against infection of the babies' gut during delivery.
