Colonization levels of Streptococcus mutans between mother and infant: a postnatal prospective cohort study

To investigate the possible association between maternal S. mutans levels and those of the infant during the period between birth and 5 months and evaluate possible risk factors in the S mutans colonization. A prospective cohort study was carried out comprising 62 infants and their mothers, selected at the time of childbirth. For each infant, a sample swab was taken at 0, 15, 30, 90, and 150 days postpartum; on the same days, a sample was obtained from the mothers. TYCSB medium was employed for identifying the microorganism, which was later confirmed by Gram staining, the catalase activity test, and the API strep test. The final total sample consisted of 60 infants, from which S. mutans was detected in only 2 (3%) at the 150th day of oral sample collection. Of the sample of 60 mothers, 54 exhibited colonization levels. In the studied sample pairs up to 150 days, it was not possible to demonstrate the presence of a direct relationship between maternal S. mutans oral levels.