Similarity of bacterial populations in saliva from African-American mother-child dyads

Abstract

Using PCR-based denaturing gradient gel electrophoresis analyses of oral bacterial samples in 20 mother-child dyads, this study demonstrated a high degree of similarity of bacterial compositions between the mothers and their children; the two may share as much as 94% of their oral bacterial spectra, including cariogenic species.

FIG. 1.

Negative DGGE images of the 20 mother-child pairs (lanes 1 to 20). All DGGE gels were normalized first and then analyzed based on the position and intensity of each band detected. The DGGE profile analysis clearly shows different banding patterns of bacterial populations in the saliva between mother-child pairs and mother-nonchild pairs. M, mother; C, child.

FIG. 2.

Comparison of the DGGE banding patterns between a mother-child pair (no. 12) (A) and mother-nonchild pairs (B). The Dice correlation coefficient for pairwise comparisons was generated by Fingerprinting II Informatix software (BioRed). (A) A C_s of 94.4% was calculated for mother-child pair 12, which indicates a high degree of similarity between the mother-child pair. (B) In contrast, the mean C_s was 69.3% when comparing a child with other female adults. M1, M4, M8, and M18 represent mothers 1, 4, 8, and 18; C12 represents child 12.

FIG. 3.

The mean similarity value for the mother-child pairs was 83.5% ± 6.9% (range from 67% to 94%). In contrast, the mean similarity value for the mother-nonchild pairs was 69.3% ± 3.7% (range from 59% to 74%). The differences were highly statistically significant (nonparametric [NPar] Mann-Whitney test; P < 0.001).