Evaluation for association between maternal microbiota and development of necrotizing enterocolitis or gram-negative bacteremia in preterm infants

Date of Award


Document Type


Degree Name

Master of Medicine (MMed)

First Supervisor/Advisor

Prof. Rodney Adam

Second Supervisor/Advisor

Dr. Roseline Ochieng


Paediatrics and Child Health (East Africa)


Background: Preterm birth is the leading cause of perinatal morbidity and mortality worldwide. There is a need for a better understanding of the correlation of vaginal microbiota with adverse preterm outcomes. Our study aimed to explore how the vaginal microbiota influences the outcome of the preterm infants, determine whether fecal microbiota in premature infants differs from that in term infants, and explore the microbiota pattern in preterm neonates who received multiple antibiotics.

Method: A prospective cohort design was used to enroll 33 women admitted in spontaneous labor between 25 to 36 weeks, and 33 controls matched for age and parity who presented in labor after 37 weeks. At birth, the infants of the women in preterm labour were also enrolled. We obtained a vaginal swab from the mother before delivery, infant rectal swabs, or stool samples. These samples were assessed using 16S ribosomal RNA (rRNA) gene sequencing. Using a bioinformatics approach phylogeny trees were created. Beta-diversity was calculated using permutational Multivariate Analysis of variance.

Results: The dominant species found in both maternal vaginal microbiota in the preterm infants with endpoints (Necrotizing enterocolitis or Gram-negative bacteremia) and the maternal vaginal microbiota of healthy preterm infants were Lactobacillus. There is no difference in diversity between the two groups. There was a higher Firmicutes to Bacteroidetes ratio observed in the maternal vaginal microbiota of the preterm infants with endpoints. The gut microbiota of the term infants was more diverse (AMOVA p=<0.001) compared to the gut microbiota of the preterm infants, and it was predominantly Enterococcus, Bifidobacterium, and Streptococcus.

Conclusions: The term infant’s gut microbiota was more diverse than the gut microbiota of the preterm infants. The relationship of Firmicutes to Bacteroidetes ratio in maternal vaginal microbiota with adverse neonatal outcomes was not explored adequately. Studies, including a larger cohort of infants from different study centers, are needed to investigate further the association of microbiota of the preterm infants with their adverse outcomes.

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