Related Experiment Video
Updated: May 22, 2026

Assessment of Intestinal Transcytosis of Neonatal Escherichia coli Bacteremia Isolates
Published on: February 17, 2023
Molecular characterization of bacterial colonization in the preterm and term infant's intestine
J C Hallab1, S T Leach, L Zhang
1School of Biochemistry and Biotechnology, University of New South Wales, Sydney, Australia.
Objective:
To further define patterns of colonising intestinal microflora in newborn infants utilising molecular methods.
Methods:
Ten term and 5 preterm (<32 wk) infants born at the Royal Hospital for Women, Sydney, Australia were enrolled in the present study and followed for 6 mo post partum. Serial stools were collected, DNA was extracted and subjected to PCR-Denaturing Gradient Gel Electrophoresis using a range of primers and sequencing. The effect of gestational length, feeding and delivery method was compared to the pattern of bacterial acquisition.
Results:
Intestinal bacterial diversity was lower in preterm compared with term infants. For term infants, bacterial DNA detection rates were not associated with feeding or delivery method, although Enterobacteria and Clostridia were commonly identified. The detection rate of Bifidobacteria was lower in preterm infants than term infants. Potential pathogens were detected in preterm infant samples.
Conclusions:
Preterm infants frequently have aberrant bacterial colonization of the intestine. Further research is now required to determine if this may contribute to adverse health outcomes.
Related Concept Videos
Development of the Oral Microbiota
Development of Human Microbiota
Introduction to the Human Microbiota
Anatomy of the Intestines
Small Intestines
The small intestine is an ~7 meter-long tube with an inner diameter of just 2.5 cm. Since most nutrients are absorbed here, the inner lining of the small...
Bacterial Flora of the Large Intestine
The normal gut flora of the colon plays a critical role in generating essential vitamins such as vitamins K, B5, and B7.
Microbiota of the Large Intestine

