The Fidelity of Mutans Streptococci Transmission and Caries Status Correlate with Breast–Feeding Experience among Chinese Families

Abstract

Our previous study reported that the fidelity of mutans streptococci (MS) transmission from mother to infant was gender– and race–specific within a Birmingham, Ala., population. We hypothesized that fidelity might be a function of postnatal nurturing practices. The purpose of the present study was to investigate those factors that could be correlated with MS transmission among Chinese children whose nurturing histories were known. Forty–eight families with 2– to 3–year–old children were selected from two kindergartens of Beijing, China. A questionnaire concerning the childhood nursing practice was obtained from the parents. Dental caries status was examined, and bacterial samples were collected for all participants twice at 6–month intervals. An average of six isolates of MS was picked at random from selective medium from each individual at each visit. Chromosomal DNA fingerprints were performed for all MS isolates to determine the genomic similarity within each family and among individuals. The results showed that 66% of the children at 2–3 years of age harbored MS, and 46% were caries–active. Of those children, 70% were breast–fed. Among the children whose chromosomal DNA fingerprint genotypes of MS matched that of their mothers, 88% were breast–fed compared with only 12% who were not breast–fed (p = 0.03). We also found that children who were breast–fed for more than 9 months were likely to harbor strains of MS common to their mothers (p = 0.04) and experience more dental caries (dmft = 4.4) at 3 years of age compared with children who were breast–fed less than 9 months (dmft = 1.4, p = 0.04). The data suggest that breast–feeding, especially prolonged breast–feeding, may correlate with the fidelity of transmission and that prolonged breast–feeding may contribute to a higher caries rate.

Longitudinal Study of Transmission, Diversity, and Stability of Streptococcus mutans and Streptococcus sobrinus Genotypes in Brazilian Nursery Children

“…respectively, suggesting vertical transmission. This rate was higher than previously reported in several studies, with ranges between 24 and 71% (1,4,8,18,20,21,24). On the other hand, these results are very similar to a longitudinal study of intrafamilial MS ribotypes that showed at least one common S. mutans ribotype among strains recovered from 14 mother-child pairs; among those pairs, 12 pairs (85%) shared the same ribotype; and among eight maternal strains of S. sobrinus ribotyped, six strains (75%) were detected in the child (14).…”

Longitudinal Study of Prolonged Breast- or Bottle-feeding on Dental Caries in Japanese Children

“…This finding is in accordance with the results of the study by Eronat & Eden 5) , who found that most children with rampant caries were breast-fed for longer than 12 months. Li et al 8) also reported that children who were breast-fed more than 9 months were 5 times more likely to have dental caries at 3 years of age than those who had not been breast-fed.…”

Maternal Oral Bacterial Levels Predict Early Childhood Caries Development

“…We hypothesize, however, that the association between maternal cariogenic salivary bacteria and child caries might be strongest under contexts entailing close maternal contacts (e.g., breastfeeding, utensil sharing) and weaker under contexts that imply broader potential sources of infection (e.g., daycare attendance, having siblings). For example, greater fidelity of maternal and child MS genotypes was observed among MS-positive children who were breastfed (Li et al, 2000). If observed, such effect measure modification would strengthen the mechanistic evidence inculpating maternal bacterial transfer as a caries determinant among children, representing an area for future study.…”