| Project/Area Number |
10460137
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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 | 一般 |
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| Research Field |
Applied veterinary science
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| Research Institution | Iwate University |
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Principal Investigator |
SHINAGAWA Kunihiro Iwate University, Veterinary medicine, Professor, 農学部, 教授 (60133906)
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| Co-Investigator(Kenkyū-buntansha) |
ITO Kikuji Tokyo University, Veterinary Medicine, Associate Professor, 農学生命科学研究科, 助教授 (50100045)
NAKANE Akiko Hirosaki University, Midecine, Professor, 医学部, 教授 (30164239)
SATO Shigerito Iwate Medical University, Medicine, Professor, 医学部, 教授 (20112592)
NAKAZAWA Muneo National Institute of Animal Health, Laboratory of Zoonosis, Chief, 家畜衛生試験場, 室長(研究職)
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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 |
¥13,800,000 (Direct Cost: ¥13,800,000)
Fiscal Year 1999: ¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 1998: ¥9,800,000 (Direct Cost: ¥9,800,000)
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| Keywords | Shiga toxin-producing Escherichia coli / bovine colostrum / anti-O antigen antibody / cytokines / Shiga toxin (Stx) / mice lethality / Enterohemorrhagic E.coli / Escherichia coli O157:H7 / O157 Ig-G抗体価 / 志賀毒素 1 / 志賀毒素 2 / 志賀毒素 Ig-G抗体価 |
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| Research Abstract |
To investigate the frequency of Shiga toxin-producing Escherichia coli (STEC) infected calves at a breeding farm, the plymerase chain reaction (PCR) was used for detection of genes for Shiga toxin (s). The prevalence rates in calves less than 2 months of age, cattle 2-8 months age, and adults greater than 1 year of age were 39.4, 79, and 40.8%, respectively. Detection frequency of STEC in the fecal specimens from calves aged 0-8 months was not different among the breeds of cattle (Holstein, Japanese black cattle, F1 : HxB).
Passive immunity against STEC from cows to newborn calves through colostrum was studied. Antibody titers in colostrum and sera from cows and newborn calves were determined by enzyme-linked immunosorbent assay (ELISA). The obtained results indicate that antibody titer to STEC in colostrum from cows soon after parturition was the highest one. The first consumption of colostrum with high antibody titer elevated serum antibody titer from newborn calves at 4-9 hours after
… More
birth, suggesting a correlation between antibody titer in colostrum (and sera of cows) and newborn calves. From this result, passive immunity to STEC infection is found to be occurred in newborn claves through colostrum. Suggests a new way to protect newborn calves against STEC infection.
We assess that possibility of proinflammatory cytokines such as gamma interferon (IFN-γ) or tumor necrosis factor-alpha (TNF-α) mediate lethality of Stx1 or Stx2. All of mice died within 3 to 4 days after injection with 400 ng of Stx1, a lethal dose of Stx2 was lower 40-times than that of Stx1. When mice were given 400 ng of Stx1 or 10 ng of Stx2, IFN-γand TNF-α production in the sera and spleens was not observed 1 h to 6 h after injection. However, when mice were injected with 133 ng of Stx1 or 3.3 ng of Stx2, IFN-γ -deficient mice and TNF-α-deficient mice significantly survived, compared with C57BL/6 mice, suggesting that undetectable levels of both IFN-γ and TNF-α are involved in lethality of Stx. The present study using cytokine-gene knockout mice directly demonstrated that both IFN-γ and TNF-α are involved in lethality of Stx1 and Stx2. Less
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