title: [Acquisition of Mutans streptococci by children of 3-4 years with possible source of the pathogen from their mothers].
abstract: OBJECTIVE
  The aim of this study was to investigate the prevalence of Mutans streptococci (MS) in children of 3-4 years and thus reveal the relationship between the children's acquisition of MS and their mothers' pathogen.
  
  
  METHODS
  Fifty mother-child pairs were selected, examined and divided into three groups according to the children's caries. MS in plaque and mothers' salivary samples were detected by MSB medium. Then 200 MS strains from 20 mothers-children were analyzed by AP-PCR.
  
  
  RESULTS
  Acquisition of MS was identified in 37 of 50 children (74%), including 11 of 24 caries-free children and all 26 children with caries. The difference was significant (P<0.01). Genotypes showed that 16 of 37 children (43.2%) had the same fingerprint as their mothers'. The level of MS identified in mothers' salivary sample was lower than that in mothers' plaque sample (32% and 56%).
  
  
  CONCLUSIONS
  These results suggested that caries in children of 3-4 years are closely related with MS acquisition. Mothers are still their important source of MS. The sensitivity of mothers' salivery samples is much lower than that of plaque samples in studying the transmission of MS.
authors.affiliation: Department of Endodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Tian-jia
authors.initials: TJ
authors.lastname: Liu
authors.forename: Xiao-rong
authors.initials: XR
authors.lastname: Xiao
authors.forename: Wei-wei
authors.initials: WW
authors.lastname: Ye
mesh_terms: D000328:Adult; D002675:Child, Preschool; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D003731:Dental Caries / Q000382:microbiology* / Q000517:prevention & control; D003732:Dental Caries Activity Tests; D005260:Female; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D009035:Mothers; D013295:Streptococcus mutans / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial