| Project/Area Number |
10357003
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 | National Institute of Infections Diseases (1999-2000)
Research Institute, International Medical Center of Japan (1998) |
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Principal Investigator |
TAKEDA Yoshifumi National Institute of Infections Diseases, Director - General, 所長 (30029772)
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| Co-Investigator(Kenkyū-buntansha) |
YAMASAKI Shinji Research Institute, International Medical Center of Japan, Division Director, 適正技術開発・移転研究部, 室長 (70221653)
HAMABATA Takashi Research Institute, International Medical Center of Japan, Division Director, 感染・熱帯病研究部, 室長 (40311427)
MAKINO Sou-ichi Department of Veterinary Microbiology, University of Agriculture and Veterinary Medicine, Associate Professor, 畜産学部, 助教授 (30181621)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥32,500,000 (Direct Cost: ¥32,500,000)
Fiscal Year 2000: ¥9,000,000 (Direct Cost: ¥9,000,000)
Fiscal Year 1999: ¥9,500,000 (Direct Cost: ¥9,500,000)
Fiscal Year 1998: ¥14,000,000 (Direct Cost: ¥14,000,000)
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| Keywords | Enterohemorrhagic Escherichia coli / Non-toxic mutant / Vaccine strain / Porcine edema disease / VT2vp1 / Protective efficacy / Vero toxin / Stx2 / 生菌ワクチン / VT2 / 幼弱ウサギ / 幼弱ブタ / 無毒変異毒素 / 無毒変異要素 |
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| Research Abstract |
Enterohemorrhagic Escherichia coli(EHEC) is isolated from not only humans but also from cattle. EHEC infection in cattle such as cows and pigs is a big prolem and EHEC contaminated in feces of human infection. Thus a development of a vaccine strain against EHEC infection in cattle may prevent the occurrence of EHEC infection in human, and therefore prevent a complication such as hemolytic uremic syndrome.
In this study we developed a vaccine strain of EHEC that causes porcine edema disease. Effectiveness of the developed vaccine strain was also demonstrated. A mutant strain constructer retained immunogenicity but lost Vero cell cytotoxicy, and produced genetically modified toxin by replaciy glutamate with glutamine at position 167 and ayine with leucine at position 170 of the A subunit of Vero toxin (Stx2e). As the parent wild strain was pathogenic to pigs but the mutant strain was not, the mutant strain named as YT106 was given to the pigs to examine its protective immunity against edema disease. All 20 pigs vaccinated with TY106 survived but only 8 of 20 nonvaccinated pigs survived after the challenge with a wild strain. Also, the 8 survived pigs had decreased rates of gain relative to those of the controls. Blood IgG and intestinal IgA titers increased 3.3 and 1.6 times, respectively, more then the control, showing that YT106 might be a good candidate of a live-attenuated vaccine strain to protect against edema disease.
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