title: [Study on the genetic diversity within the extended-V region of the surface protein of Streptococcus mutans].
abstract: OBJECTIVE
  The purpose of this study was to investigate the genicity of the extended- variable region (V+) of surface proteins of Streptococcus mutans (S. mutans, serotype c,f) and provide some genetic informations on the molecular structure of S. mutans surface protein.
  
  
  METHODS
  7 standard strains and 110 clinical isolates of S.mutans were selected.The bacterial DNA was extracted and the extended-V region (srV+ 1384-2514 bp) was amplified using polymerase chain reaction (PCR). The genetic diversity of srV+ was assessed by using restriction fragment length polymorphism (RFLP) with restriction endonuclease DdeI.
  
  
  RESULTS
  The results showed that five different patterns (A,B,C,D,E) of the PCR-RFLP among the 117 strains were reveled by DdeI. The ration of the genotype A and B were the most among the strains, C followed by genotype, the D and E were 1 and 3 strains per genotype, respectively.OMZ175 (serotype f) belonged to B genotype.
  
  
  CONCLUSIONS
  The study supported that the extended-variable region (srV+) of the surface proteins of Streptococcus mutans have diversity. There are five patterns of genotypings. The most genotypings were p1-like,spaP /sr-like and pac-like.
authors.affiliation: Department of Oral Medicine, Wenzhou Medical College, Wenzhou 325000, Sichuan Province, China.
authors.forename: Kui-fang
authors.initials: KF
authors.lastname: He
authors.forename: Jian-guo
authors.initials: JG
authors.lastname: Liu
authors.forename: Tian-jia
authors.initials: TJ
authors.lastname: Liu
authors.forename: Heng
authors.initials: H
authors.lastname: Zhuang
authors.forename: De-qin
authors.initials: DQ
authors.lastname: Yang
authors.forename: Yi-huai
authors.initials: YH
authors.lastname: Pan
mesh_terms: D004269:DNA, Bacterial / Q000032:analysis; D015252:Deoxyribonucleases, Type II Site-Specific; D014644:Genetic Variation; D005838:Genotype; D008565:Membrane Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D013295:Streptococcus mutans / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D008565:Membrane Proteins; C027908:endodeoxyribonuclease DdeI; D015252:Deoxyribonucleases, Type II Site-Specific