TABLE 2.
Distribution and number of S. mutans genotypes isolated from oral cavities of 16 mother-child pairs at time of S. mutans initial acquisition and during follow-up
| Group (%)a | Pair no. (gender)b |
S. mutans genotype(s) in childreng
|
S. mutans genotype(s) in mothersg | |
|---|---|---|---|---|
| Initial acquisition, ageh | Followupi | |||
| Matching (81.25) | 2 (F)c | 3 (A,B,C), 15.4 | 2 (A*, D) | 1 (A) |
| 3 (F) | 3 (A, B, C), 16.8 | 1 (B*, D) | 1 (A) | |
| 4 (F) | 1 (A), 17.6 | 1 (A*) | 4 (A, B, C, D) | |
| 5 (F) | 2 (A, B), 14.2 | 2 (A*, B*) | 2 (A, B) | |
| 7 (M)d | 1 (C), 17.8 | 2 (A, D, E) | 2 (A, B) | |
| 8 (F)ef | 2 (A, B), 12.8 | 5 (A*, B*, C, D, E) | 3 (A, B, C) | |
| 10 (M)d | 1 (C), 11.6 | 2 (A, D) | 2 (A, B) | |
| 12 (M) | 1 (A), 16.6 | 1 (E) | 4 (A, B, C, D) | |
| 13 (F) | 1 (A), 14.5 | 1 (A*) | 2 (A, B) | |
| 17 (F) | 1 (A), 16.6 | — | 1 (A) | |
| 20 (F) | 2 (A, C), 13.4 | 2 (A*, C) | 2 (A, B) | |
| 23 (F)f | 2 (A, B), 16.1 | 4 (C, D, E, F) | 2 (A, B) | |
| 24 (M) | 2 (A, C), 18 | — | 1 (A) | |
| Nonmatching (18.75) | 18 (M) | 4 (F, G, H, J), 14.6 | 2 (I, L) | 5 (A, B, C, D, E) |
| 28 (F) | 1 (C), 18.4 | 5 (D, E, F, G, H) | 2 (A, B) | |
| 32 (M) | 3 (C, D, E), 12.6 | 2 (D*, E*) | 2 (A, B) | |
| Total of distinct genotypes detected | 30 | 22 | 36 | |
| Total of genotypes transmitted | 13 | 3 | 16 | |
Fisher's exact test showed statistical difference among the number of children who acquired or did not acquire S. mutans genotypes from their mothers (P = 0.0011).
Number of pairs = 16. Gender, gender of child; M, male; F, female.
The child in pair 2 is the only child who showed incipient caries on the buccal surfaces of the upper anterior incisors. No other child showed caries lesions during this study.
The children from pairs 7 and 10 did not acquire genotypes from their mothers at the time of initial acquisition. However, these children acquired S. mutans from their mothers in later samplings.
The child in pair 8 acquired one more genotype from his mother in later samplings, in addition to genotypes acquired the at the time of initial acquisition.
The children from pairs 8 and 23 acquired two genotypes from their mothers at the time of initial acquisition.
Letters in parentheses indicate genotypes detected in the subjects. Genotypes indicated by the same letters are identical only within that mother-child pair and bear no relation to types indicated by the same letter in any other mother-child pair.
Age is indicated in months.
Asterisks indicate S. mutans genotypes considered to be stable genotypes. [—], S. mutans was not isolated in posterior samplings.