Bacterial Profile of the Oropharynx in Infants: An Assessment of the Confounding Factors for Colonization

Abstract

To determine the composition of non pathogenic microflora (NPM) and pathogenic microflora (PM) and the assessment of factors affecting their colonization in the oropharynx. Oropharyngeal swabs were obtained from 464 infants, aged 15 days to I year, with or without clinical signs and symptoms of upper respiratory tract infection (URTI), for the current study.Culture was done on blood and chocolate agar, and the colonies were identified using standard microbiological procedures. The influence of age, presence of siblings and feeding patterns on colonization of oropharynx and the profile of NPM and PM in symptomatic and asymptomatic infants was studied. Colonization of oropharynx by NPM decreased with age whereas by PM increased with age significantly. Isolation of PM significantly increased in cases having siblings less than 18 years of age at home. Season showed a significant influence on the colonization of microflora in the oropharynx. Colonization by NPM was significantly higher in exclusively breast fed (EBF) infants, whereas by PM was higher in mixed fed (MF) infants. Symptomatic infants were higher in the MF group than in EBF group. Certain species of NPM exhibited significant inhibitory effects on colonization of PM. Assessment of the factors influencing the oropharyngeal colonization of microflora in infants identifies the risk factors for various infections in later life.