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Updated: May 15, 2025

Oral Biofilm Sampling for Microbiome Analysis in Healthy Children
Published on: December 31, 2017
The Ages When Healthy Children Are First Colonized by Three Common Potentially Pathogenic Bacteria: A Birth Cohort
Sumanta Saha1, Nicolette Fozzard2, Keith Grimwood3
1From the Department of Paediatrics and Child Health (Dunedin), University of Otago, New Zealand.
Insights
Early airway colonization by Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae was tracked in infants. RNA viruses correlated with the initial detection of Haemophilus influenzae in the airways.
Area of Science:
- Pediatric microbiology
- Respiratory tract infections
- Early life microbial colonization
Background:
- Limited data exists on the initial colonization timing of key respiratory pathogens in infants.
- Understanding early bacterial colonization is crucial for developing preventative strategies against respiratory illnesses.
Purpose of the Study:
- To determine the median age of first detection for Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae in infants.
- To explore potential associations between viral infections and the colonization of these bacteria.
Main Methods:
- A prospective birth cohort study involving 158 Australian infants.
- Weekly nasal swabs were collected to identify bacterial presence.
- Statistical analysis was performed to determine median ages and associations.
Main Results:
- The median ages for first detection were 3.0 months for Streptococcus pneumoniae, 5.5 months for Moraxella catarrhalis, and 11.2 months for Haemophilus influenzae.
- A significant association was observed between the presence of RNA viruses and the first detection of Haemophilus influenzae.
Conclusions:
- This study provides critical insights into the early colonization dynamics of common airway bacteria in infants.
- The findings suggest a potential role for viral infections in facilitating Haemophilus influenzae colonization, warranting further investigation.
Abstract:
Limited information exists for when potentially pathogenic bacteria first colonize the airways. Weekly nasal swabs from an Australian birth cohort (N = 158) revealed the median (interquartile range) ages when Streptococcus pneumoniae , Moraxella catarrhalis and Haemophilus influenza e were first detected as 3.0 (0.8-7.1), 5.5 (2.8-8.7) and 11.2 (6.4-18.0) months, respectively. RNA viruses were associated with first H. influenzae detections.

