| Project/Area Number |
03670217
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
細菌学
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| Research Institution | Kagawa Medical School |
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Principal Investigator |
OKABE Akinobu Kagawa Medical School Professor, 医学部, 教授 (20093677)
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| Co-Investigator(Kenkyū-buntansha) |
KATAYAMA Sei-ichi Kagawa Medical School Assistant Professor, 医学部, 助手 (70169473)
MINAMI Junzaburo Kagawa Medical School Lecturer, 医学部, 講師 (40157566)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1992: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1991: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Clostridium / C.perfringens / Bacterial toxin / Histotoxicity / Toxin genes / Collagenase / クロストリジウム / 組織侵襲 / α毒素 / θ毒素 / κ毒素 |
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| Research Abstract |
Genes encoding for alpha-and theta-toxins of Clostridium perfringens(type A NCTC 8237)were separately cloned into pHY300PLK and expressed in Bacillus subtilis ISW 1214(spoo^).Levels of both the alpha- and theta-toxins produced by each strain were almost the same as those by C.perfringens. Viability of these two strains within a macrophage was examined using macrophage cell line SV-BP-1.The theta-toxin producing strain increased in number within the macrophage,while the alpha-toxin producing strain decreased similarly to a control.The result indicates that the theta-toxin functions as an antiphagocytic determinant but the alpha-toxin does not.
Virulence of the two strains was examined by determining lethal dose against a mouse. When the alpha-toxin producing strain was injected interperitoneally,it was more virulent than the theta-toxin producing strain. On the other hand,the former was less virulent than the latter when injected intravenously. A plasmid carrying the two toxin genes was also constructed.B subtilis carrying this plasmid produced the theta-toxin in large amounts but the alpha-toxin in a very small amount. However,the strain producing the two toxins exhibited mouse lethality to the same extent as the two alpha- and theta-producing strains used in combination, suggesting that a synergistic effect of the two toxins may be enhanced if they are produced by a single cell into microenvironment surrounding a bacterial cell.
A 120-KDa C.perfringens collagenase(k-toxin)was found and purified. Its encoding gene was cloned and sequenced. The nucleotide sequence shows that the toxin belongs to Zn metalloproteinase and is homologous to other bacterial proteinase and collagenase.
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