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1999 Fiscal Year Final Research Report Summary

Bacteriological study on pathogenicity and drug resistant of oral streptococci

Research Project

Project/Area Number 09470461
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Surgical dentistry
Research InstitutionTsurumi University

Principal Investigator

ISIBASHI Katsumnori  Tsurumi University, School of dental medicine, Professor, 歯学部, 教授 (20013980)

Co-Investigator(Kenkyū-buntansha) SASAKI Fumihiko  Tsurumi University, School of dental medicine, Instuctor, 歯学部, 助手 (10318917)
NAGASIMA Hiroyuki  Tsurumi University, School of dental medicine, Instructor, 歯学部, 助手 (70257343)
NAKAGAWA Yoiti  Tsurumi University, School of dental medicine, Lecture, 歯学部, 講師 (90148057)
Project Period (FY) 1997 – 1999
KeywordsOral steptococci / Pathogenicity / Penicillin binding proteins
Research Abstract

Oral streptococci are the most predominant oral bacteria, and are related to odontogenic infection and infectious endocarditis. However, the pathogenicity of oral streptococci has not been sufficiently evaluated and little has been known about the mechanism of infection. Recently, there have been reports of acquisition of resistance to β-lactam agents caused by the alteration of penicillin binding proteins(PBPs) in some species of this bacterial genus which were previously sensitive to the agents.
In this study, we evaluated the pathogenicity of β-lactam agent resistant stains of oral streptococci in the treatment of infection. Regarding the evaluation of pathogenicity, we analyzed the pathogenicity of Streptococcus milleri group which was frequently isolated from oral obstructive abscess and the influence of the mixed infection by the S.milleri and anaerobic Fusobacterium nucleatum. An increase size in abscess was observed in the mixed inoculation of S.milleri and F.nucleatum compared … More to the single inoculation of the S.milleri group. An increase in the initial proliferation of S.constellatus was observed by mixing the supernatant liquid of cultures for F.nucleatum, with a decrease in phagocytosis of S.constellatus by polymorphonuclear leukocytes and slight inhibition of inflammatory cytokine production. These results suggested that the pathogenicity of the S.milleri group was enhanced by the presence of F.nucleatum in odontogenic infection. Regarding the evaluation of drug resistance, there was the possibility that β-lactam agent resistant streptococci in the indigenous microbiota are present in the normal oral cavity, and a decrease in drug affinity of PBPs in isolated resistant strains was observed. The elucidation of the tendency to acquire resistance and the resistance mechanism of oral streptococci may be important for understanding the pathogencity of oral streptococci, since they have their own latent pathogenicity and a possibility of a potential resistant gene source of Streptococcus pneumoniae. Less

  • Research Products

    (4 results)

All Other

All Publications (4 results)

  • [Publications] 長島弘征: "Abscess forming ability of streptococcus milleri group : synergistic effect with Fusobacterium nucleatum"Microbiology and Immunology. 43・3. 207-216 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 佐々木文彦: "健康成人から分離されたampicillin耐性streptcocciのβ-lactam薬感受性とpenicillin binding proteinsに関する検討"日本化学療法学会雑誌. 46・10. 375-386 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Hiroyuki Nagasima: "Abscess forming ability of streptococcus milleri group : Synergistic effect with Fusobacterium nucleatum."Microbiol., Immunol. 43(3). 207-216 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Fumihiko Sasaki: "Study on β-lactam antibiotic susceptibilities and characteristics of penicillin binding proteins of ampicillin resistant streptococci isolated from healthy adults' saliva"Chemotherapy. 46(10). 375-386 (1998)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 2001-10-23  

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