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The Roles of the Virulence Factors of Shigella Flexneri in Cell to Cell Spread.

Research Project

Project/Area Number 63480151
Research Category

Grant-in-Aid for General Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field 細菌学
Research InstitutionThe University of Tokyo

Principal Investigator

SASAKAWA Chihiro  Inst. of Med. Sci. Univ. of Tokyo, Asso. Prof., 医科学研究所, 助教授 (70114494)

Co-Investigator(Kenkyū-buntansha) OKADA Nobuhiko  Inst. of Med. Sci. Univ. of Tokyo. Res. Asso., 医科学研究所, 助手 (80194364)
Project Period (FY) 1988 – 1990
Project Status Completed (Fiscal Year 1990)
Budget Amount *help
¥5,900,000 (Direct Cost: ¥5,900,000)
Fiscal Year 1990: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1989: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1988: ¥1,800,000 (Direct Cost: ¥1,800,000)
KeywordsShigella / Virulence / intercellular spread / invasion / gene regulation / 上皮細胞 / 染色体 / LPS / ビルレンス遺伝子 / 下痢 / 病原性 / プラスミド / 遺伝子解析
Research Abstract

Shigellae cause bacillary dysentery in humanas, and this constitutes a major public health problem in developing countries. The early essential step leading to dysenteric symptoms is invasion of colonic epithelial cells, followed by intraellular bacterial multiplication and spread of invading bactera to adjacent cells.
In Shigella flexneri, various chrmosomal loci have been shown to be associated with its pathogenicity. While on the large (230 kb) plasmid of S. flexneri, seven choromosomal loci (virF, virB, ipaBCD, Region-3, -4, and -5, and virG) have been identified by our previous studies. One of the plasmid born virulence locus, virG, was shown to be required for the invading bacteria to spread intracellularly and intercellularly through inducing the aggregation of F-actin. The expression of the virG gene was indicated to be under the controls of the transcriptional activation by the virF gene and the post-transcriptional regulaion by one of the chromosomal locus, kcpA. To identify genes on the choromosome associated with the virulence phenotypes of the primary invation, multiplication and spread, approximately 10.000 Tn5 insertion mutants were isolated by using an in vitro assay system. Fifty mutants with reduced virulence were characterized with respect to their virulence phenotypes, including three different mutations that affect invasion of epithelial cells, bacterial metabolism and structures of lipopolysaccharide. Assignment of the fifty Tn5 insertions of the mutansts to the 19 NotI restriction fragments of the chromosomal DNA has permitted the identification of at least nine virulence-associated chromosome loci. These study will become basis for the molecular study on the role of each virulence locus in the spread of invading bacteria to the adjacent epithelial cells.

Report

(4 results)
  • 1990 Annual Research Report   Final Research Report Summary
  • 1989 Annual Research Report
  • 1988 Annual Research Report
  • Research Products

    (24 results)

All Other

All Publications (24 results)

  • [Publications] M,Yamada: "Molecular cloning and characterization of chromosomal virulence region kcpA of Shigella flexneru." Mol.Microbiol.3. 207-213 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] B.Adler: "A dual transuriptional activation system for the 230Kb plasmid genes coding for virulenceーasscliated antigens of Shigella flexneri." Mol.Microbiol.3. 627-635 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] C.Sasakawa: "Functional organization and nucleotide sequence of virulence Regionー2 on the large viruleuce plasmid in Shigella flexneri 2a." Mol.Microbiol.3. 1191-1201 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] N.Okada: "Virulenceーassociated chromosomal loci of Shigella flexneri identified by random Tn5 insertion mutagenesis." Mol.Microbiol. 5. 187-195 (1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] T.Tobe: "Temperatureーregulated expression of invasion genesin Shisella flexneri is controlled through the transciptional activation of the virB gene on the large plasmid." Mol.Microbiol.(1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] M. Yamada,: "Molecular cloning and characterization of chromosomal virulence region kcpA of Shigella flexneri." Mol. Microbiol.3. 207-213, (1989)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] B. Adler,: "A dual transcriptional activation system for the 230 kb plasmid genes coding for virulence-associated antigens of Shigella flexneri." Mol. Microbiol.3,. 627-635, (1989)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] C. Sasakawa,: "Functional organization and nucleotide sequence of virulence Region-2 on the large virulence plasmid in shigella flexneri 2a" Mol. Microbiol.3,. 1191-1201 (1989)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] N. OKada,: "Virulence-associated chromosomal loci of Shigella flexneri identified by random Tn5 insertion mutagenesis." Mol. Microbiol.5. 187-195, (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] T. Tobe: "Temperature-regulated expression of invasion genes in Shigella flexneri is controlled through the transcriptional activation the virB gene on the large plasmid." Mol. Microbiol.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] C.Sasakawa: "Functional origanization and nucleotide sequence of virulence Regionー2 on the large virulence plasmid in <Shigella>___ー <flexneri>___ー 2a." Mol.Microbiol.3. 1191-1201 (1989)

    • Related Report
      1990 Annual Research Report
  • [Publications] N.Okada: "Virulenceーassociated chromosomal loci of <Shigella>___ー <flexneri>___ー identified by random Tn5__ー insertion mutagenesis." Mol.Microbiol.5. 187-195 (1991)

    • Related Report
      1990 Annual Research Report
  • [Publications] T.Tobe: "Temperatureーregulated expression of invasion genes in <Shigella>___ー <flexneri>___ー is controlled" Mol.Microbiol.(1991)

    • Related Report
      1990 Annual Research Report
  • [Publications] C.Sasakawa: "The lorge virulence plasmid of <Shigella>___ー." Cur.Topics.Microbiol.Immunol.(1991)

    • Related Report
      1990 Annual Research Report
  • [Publications] M.Yamada: "Molecular cloning and characterization of chromosomal viralence region KcpA of Shigella flexneri" Mol.Microbiol.3. 207-213 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] B.Adler: "A dual Transuiptional activation system for the 230 kb plasmid genes coding for virulence-associated antigens of shigella flexneri" Mol.Microbiol.3. 627-635 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] H.Chosa: "Loss of virulence in Shigella strains preserved in culture collections dve to molecular alteration of the invasion plasmid" Microbial Pathogen. 6. 337-342 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] C.Sasakawa: "Functional organization and mucleotide sequence of virulence Region-2 on the large virulence plasmid in Shigella flexneri 2a." Mol.Microbiol.3. 1191-1201 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] Takashi,Sakai: Molecular Microbiology. 2. 589-597 (1988)

    • Related Report
      1988 Annual Research Report
  • [Publications] Souichi,Makino: Microbial Pathogenesis. 5. 267-274 (1988)

    • Related Report
      1988 Annual Research Report
  • [Publications] Masanosuke,Yoshikawa: Microbiol,Sci.5. 333-339 (1988)

    • Related Report
      1988 Annual Research Report
  • [Publications] Marie-Cl,Lett: J,Bacteriol.171. 353-355 (1989)

    • Related Report
      1988 Annual Research Report
  • [Publications] Masatoshi,Yamada: Molecular,Microbiology. 3. (1989)

    • Related Report
      1988 Annual Research Report
  • [Publications] Ben Adler: Molecular Microbiology. (1989)

    • Related Report
      1988 Annual Research Report

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Published: 1988-04-01   Modified: 2016-04-21  

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