[Study on the genetic diversity within the extended-V region of the surface protein of Streptococcus mutans].
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.
He
Kui-fang
KF
Department of Oral Medicine, Wenzhou Medical College, Wenzhou 325000, Sichuan Province, China.
Liu
Jian-guo
JG
Liu
Tian-jia
TJ
Zhuang
Heng
H
Yang
De-qin
DQ
Pan
Yi-huai
YH
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*
D004269:DNA, Bacterial; D008565:Membrane Proteins; C027908:endodeoxyribonuclease DdeI; D015252:Deoxyribonucleases, Type II Site-Specific