[A study on transmission of pathogenic bacteria of rampant caries from mothers to children].
OBJECTIVE
In order to prevent rampant caries in children, the transmission from mothers to children of pathogenic bacteria of rampant caries will be investigated in this study.


METHODS
By using fingerprint technique, the genetic diversities of Streptococcus mutans(S. mutans) were examined respectively in 10 children with rampant caries, 10 children without rampant caries S. mutans, 10 2-year-old caries-free children, and their mothers. The levels of S. mutans in saliva of mothers were also examined. For fingerprinting, chromosomal DNA of isolates obtained from plaques of these children and from saliva of their mothers were digested with restriction endonuclease HindIII and examined by electrophoresis on 0.7% agarose gel. DNA fingerprints were obtained and analyzed for genotypic similarities.


RESULTS
The DNA fingerprint patterns showed that the proportion of children whose genotypes of S. mutans matched their mothers in the children with rampant caries was 70%, which is similar to that in the children without rampant caries and the caries-free children (60% respectively). The number of distinct genotypes of S. mutans harbored in children with rampant caries was, on average, greater than the number of genotypes present in children without rampant caries and caries-free children (1.7, 1.2 and 1.1 respectively, P < 0.05). Mothers of children with rampant caries had similar levels of S. mutans in saliva as those mothers of children without rampant caries and caries-free children. However, mothers of children with rampant caries had significantly higher DMFT scores and higher levels of Streptococcus sobrinus (S. sobrinus) in saliva than the mothers of caries-free children did.


CONCLUSIONS
In all child groups, mothers were probably the main source of infection with S. mutans. Rampant caries in children is associated with DMFT scores and levels of S. sobrinus in saliva of mothers. In the initiation of rampant caries experienced by a child, the transmission of pathogenic bacteria from mothers to children may be the main source.
Liu
Y
Y
Department of Preventive Dentistry, School of Stomatology, Shanghai Second Medical University.
Liu
Z
Z
Feng
X
X
Zhu
M
M
Pan
Y
Y
D000328:Adult; D002675:Child, Preschool; D003731:Dental Caries / Q000235:genetics* / Q000382:microbiology; D005260:Female; D005838:Genotype; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D012463:Saliva / Q000382:microbiology; D013290:Streptococcal Infections / Q000235:genetics / Q000635:transmission*; D013295:Streptococcus mutans / Q000235:genetics*