Methods: Whole mouth plaque samples were collected from mother/child pairs and designated primary caregivers every 4 months. Samples were spiral plated onto selective and non-selective agars to obtain total flora, lactobacillus, and SM counts. SM isolates were identified by sugar fermentation profiles and genotyped with AP-PCR using OPA2 primer. Gels were analyzed and dendograms generated using GelCompar®IIv6.5.
Results: Individual subjects display a range of 0-4 SM genotypes. Family groups show a range of 0-6 SM genotypes. In our data set, 62.5% of the children (25/40) have established SM colonization by 16 months. Of these children, 44% share at least 1 genotype with the mother and/or caregiver. In 8 of the 13 families with a designated primary caregiver, the mother and caregiver share at least one SM genotype.
Conclusions: Our data show that there is homology of some SM genotypes in mother/child pairs and mother/child/caregiver groups. There are some genotypes observed in children that are not shared with mothers and/or primary caregivers and some shared within and across families. We continue the analyses of our data set focusing on SM genotype profiles and transmission in this population.