[Genetic diversity of F-ATPase subunits gene uncA amplified from Streptococcus mutans clinical isolates].
OBJECTIVE
To study the genetic diversity of F-ATPase alpha subunit gene uncA derived from Streptococcus mutans (S. mutans) clinical isolates and to investigate the relationship between the genetic diversity of acidurance factor and S. mutans aciduric ability, also and the cariogenicity.


METHODS
Sixty-four S. mutans strains derived from 34 caries-active individuals and 30 caries-free individuals, including 18 strains displaying high acid tolerance and 20 strains displaying low acid tolerance. Gene uncA was amplified with specific primers from S. mutans genomic DNA, then the PCR products were analyzed by RFLP and sequenced.


RESULTS
Two genotypes A and B of PCR-RFLP were revealed when digested with Hph I. Mbo II also produced two different pattern C and D. The distributions of A and B genotype strains with different caries-sensitivity groups were different (P < 0.05), and the proportion of A genotype strains from caries-activity group was higher than that from caries-free one. The distributions of C and D genotype strains with different acidurance strains were different (P < 0.05), and the proportion of C genotype strains from high acid tolerance group was higher than that from low acid tolerance group. These amplified uncA genes from different group were sequenced and there existed variation of Hph I and Mbo II recognized sites.


CONCLUSIONS
This study indicates that uncA gene of S. mutans F-ATPase obviously displayed genetic diversity. The different Hph I-RFLP and Mbo II-RFLP genotypes could be related to the cariogenicity and acid tolerance of S. mutans strains.
Yang
De-qin
DQ
Department of Operative Dentistry and Endodontics, Affiliated Hospital for Stomatology of Zunyi Medical College, Zunyi Guizhou 563003, China.
Liu
Tian-jia
TJ
Zhuang
Heng
H
Qi
Qing-guo
QG
Li
Song
S
Liu
Jian-guo
JG
D025243:Bacterial Proton-Translocating ATPases / Q000235:genetics*; D003731:Dental Caries / Q000382:microbiology*; D005798:Genes, Bacterial; D005838:Genotype; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length; D013295:Streptococcus mutans / Q000201:enzymology / Q000235:genetics*
D025243:Bacterial Proton-Translocating ATPases