Purpose: The purpose of this study was to investigate the vertical transmission of mutans streptococci (MS) and lactobacilli in a group of Thai families.
Methods: One hundred eighty-one mother-child pairs were included in this study. Unstimulated saliva was collected using the spatula method and counted for evaluating the number of MS and lactobacilli on a selective medium. Genotyping of MS and Lactobacillus species were performed in 37 and 22 child-mother pairs, respectively. Typically, 3 to 4 isolates of MS and/or Lactobacillus strains from each mother and child were collected for genotyping by an arbitrarily primed polymerase chain reaction (OPA-02 primer for MS and enterobacterial repetivive intergenic consensus primers for Lactobacillus species).
Results: Generally, MS and lactobacilli levels in children were associated with their mothers' levels. Genotyping of most isolates of MS and Lactobacillus strains in both mothers and children found diversity, and each individual showed a distinct genotypic pattern. The presence of matching genotypes of MS and Lactobacillus strains of mother-child was approximately 76% and 50%, respectively. The genotypes acquired from the maternal route show effective persistence in the children's oral cavities.
Conclusions: In Thai families, mothers can be the source for transmission of mutans streptococci and Lactobacillus strains to their children.