Research presented at the ASM Microbe research meeting provides compelling evidence that children acquire Streptococcus mutans, the bacterium most frequently associated with dental caries, from intra- and extra-familial sources besides their mother.

Children typically have more than one strain (i.e., genotype) of S. mutans  and most share at least one strain with mother or a family member. However, 72% of children in this study had 1 or more S. mutans strains not found in participating household family members indicating these strains likely came from outside the home (extra-familial transmission), possibly from other children in the populatio