A new gcrR-deficient Streptococcus mutans mutant for replacement therapy of dental caries.
BACKGROUND
gcrR gene acts as a negative regulator related to sucrose-dependent adherence in S. mutans. It is constructive to test the potential capacity of mutans with gcrR gene deficient in bacteria replacement therapy.


METHODS
In this study, we constructed the mutant by homologous recombination. The morphological characteristics of biofilms were analyzed by confocal laser scanning microscopy. S. mutans UA159 and the mutant MS-gcrR-def were inoculated, respectively, or together for competitive testing in vitro and in rat model.


RESULTS
Adhesion assay showed that the adhesion ability of the mutant increased relative to the wild type, especially in the early stage. MS-gcrR-def out-competed S. mutans UA159 in vitro biofilm, and correspondingly coinfection displayed significantly fewer caries in vivo. The former possessed both a lower level of acid production and a stronger colonization potential than S. mutans UA159.


CONCLUSIONS
These findings demonstrate that MS-gcrR-def appears to be a good candidate for replacement therapy.
The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-Most) & Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School & Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, China.
Wenting
W
Pan
Department of Stomatology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei 430060, China.
Tiantian
T
Mao
The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-Most) & Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School & Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, China.
Qing-an
QA
Xu
The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-Most) & Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School & Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, China.
Jin
J
Shao
The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-Most) & Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School & Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, China.
Chang
C
Liu
The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-Most) & Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School & Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, China.
Mingwen
M
Fan
D000818:Animals; D001426:Bacterial Proteins; D018441:Biofilms; D003731:Dental Caries / Q000382:microbiology / Q000628:therapy; D005260:Female; D017353:Gene Deletion; D051381:Rats; D017207:Rats, Sprague-Dawley; D013295:Streptococcus mutans / Q000502:physiology*; D014157:Transcription Factors
D001426:Bacterial Proteins; D014157:Transcription Factors