Construction and Isolation of streptococci useful for caries-prevention by replacement therapy

• Project/Area Number: 12671786
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Morphological basic dentistry
• Research Institution: Nihon University
• Principal Investigator: FUKUSHIMA Kazuo Nihon University, Sch. of Dent. at Matsudo, Professor, 松戸歯学部, 教授 (20009327)
• Co-Investigator(Kenkyū-buntansha): KUWAHARA Noriko (SHINOZAKI Noriko) Nihon University, Sch. of Dent. at Matsudo, Assistant, 松戸歯学部, 副手 (90287665) ; TAKEUCHI Takeo Nihon University, Sch. of Dent. at Matsudo, Research assistant, 松戸歯学部, 助手 (90171610)
• Project Period (FY): 2000 – 2001
• Project Status: Completed (Fiscal Year 2001)
• Budget Amount: ¥3,400,000 (Direct Cost: ¥3,400,000); Fiscal Year 2001: ¥1,500,000 (Direct Cost: ¥1,500,000); Fiscal Year 2000: ¥1,900,000 (Direct Cost: ¥1,900,000)
• Keywords: Caries Prevention / Replacement therapy / Streptococcus mutans / Streptococcus sobrinus / Biofilm / S. mutans / S. sobrinus

Research Abstract

Mutans streptococci, Streptococcus mutans and Streptococcus sobrinus, have been considered the principal etiological agents of dental caries. The degree of colonization of these organisms correlates with the prevalence of dental carries in, human and experimental animals. An important virulence factor of mutans streptococci promoting caries development is the abilities to colonize firmly to the tooth surface in the presence of sucrose and produce the cariogenic biofilm in situ.
The purpose of this research project was to construct or to isolate anti-cariogenic I streptococci useful for caries prevention by replacement therapy. The results have shown that a S. mutans MKM33 isolated from a caries-free student was colonizable and non-cariogenic in rats, that two S. sobrinus like isolates (HG1006 and HG988) from Dutch childs were identified as S. cricetus and both isolates also were colonizable and non-cariogenic in rats, and that a S. gordonii transformant expressing a cyclodextran-synthesizing enzyme gene was colonizable in mice. These findings suggest that the clinical isolates. MKM33, HG1006 and HG988 might be useful for caries prevention by replacement therapy. In addition, some useful microbiological methods for isolation of mutans streptococci were established, and many S. mutans were isolated from students with zero or low of caries experience, but S. sobrinus did not.

Research Products

• [Publications] 岡田珠美, 富田行秀, 田中秀雄, 藤崎宣子, 河野善治, 池見宅司, 竹内武男, 福島和雄: "高う蝕者と無う蝕者から分離したStreptococcus mutansのin vitroう蝕原性試験"日本歯科保存学雑誌. 43巻5号. 1113-1120 (2000)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Neta, T., Inokuchi, R., Kuwahara-Shinozaki, N., Kouno, Y., Ikemi, T., Fukushima, K.: "Investigation of Microbiological Methods of Estimating Individual Caries Risk : Evaluation of Sampling Methods and Materials"Int.J.Oral Biol.Med.. Vol.1 No.1(in press). (2000)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Okada, T., Tomita, Y., Ikemi, T., Fukushima, K. et al.: "In vitro cariogenicity test of Streptococcus mutans isolated from caries-susceptible and caries-free students"Jap. J. Conserv. Dent.. Vol.43(5). 1113-1120 (2000)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Neta, T., Inokuchi, R., Kuwahara-Shinozaki, N., Fukushima, K. et al.: "Investigation of microbiological methods of estimating individual caries risk : Evaluation of sampling methods and materials"Int. J. Oral Biol. Med.. Vol.1(1) (in press).
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Neta, T., Inokuchi, R., Shinozaki, N., Kouno, Y., Ikemi, T., Fukushima, K: "Investigation of Microbiological Methods of Estimating Individual Caries Risk : Evaluation of Sampling Methods and Materials"Int. J. Oral Biol. Med.. Vol.1No.1(In press). (2002)