| Project/Area Number |
10557031
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Bacteriology (including Mycology)
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| Research Institution | University of Tsukuba |
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Principal Investigator |
SHIMIZU Tohru University of Tsukuba, Institute of Basic Medical Sciences, Associate Professor, 基礎医学系, 助教授 (80235655)
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| Co-Investigator(Kenkyū-buntansha) |
OHTA Toshiko College of Medical Technology, University of Tsukuba, Professor, 医療技術短期大学部, 教授 (40233134)
HAYASHI Hideo University of Tsukuba, Institute of Basic Medical Sciences, Professor, 基礎医学系, 教授 (40033203)
倉園 久生 筑波大学, 基礎医学系, 講師 (90186487)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥13,400,000 (Direct Cost: ¥13,400,000)
Fiscal Year 1999: ¥6,400,000 (Direct Cost: ¥6,400,000)
Fiscal Year 1998: ¥7,000,000 (Direct Cost: ¥7,000,000)
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| Keywords | Clostridium perfringens / pheromone / virulence / toxin produxtion / genetic regulation |
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| Research Abstract |
One mutant strain of C. perfringens strain 13, SI112 that scarcely produce alpha-, kappa-, and theta-toxins was isolated. When the strain SI112 was cross-streaked with the virR/virS- mutant strain TS133, production of theta-toxin from SI112 was clearly observed in the crossing portion on a sheep blood agar plate. This indicated that an extracellular stimulating substance released from TS133 activated the production of theta-toxin from SI112 that could not produce the substance. We tentatively named the substance as VAP (virulence activating pheromone) and analyzed further. VAP in conditioned medium (CM) was produced mainly during the exponential phase and activated theta-toxin production at the transcriptional level. The stimulation of the pfoA gene by CM appeared to be dose-dependent. CM activated the pfoA transcription mostly at 15 min after addition, indicating a quick response to VAP exists in C. perfringens. VAP in CM seemed to be highly unstable loosing its activity within 30 min at 37゜C, and appeared to be a small molecule (M.W.<10,000). Since this extracellular communication for the virulence of C. perfringens would be important for understanding the pathogenicity and preventing infections, we are now trying to purify VAP from the culture medium of strain 13.
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