| Co-Investigator(Kenkyū-buntansha) |
KATAOKA Yasushi Nippon Veterinary and Animal Science University, Faculty of Veterinary Medicine, Associate Professor, 獣医学部, 助教授 (60277663)
YOSHIDA Takaharu Nippon Veterinary and Animal Science University, Faculty of Veterinary Medicine, Lecturer, 獣医学部, 講師 (20060527)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2004: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2003: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2002: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Research Abstract |
To clarify the epidemiological significance of Erysipelothrixiofection in cattle, antibody distribution in cattle and prevalence, serotyping, pathogenicity and molecular identification of the isolates from the tonsils of healthy cattle were studied. The results obtained are as follows.
1.Growth agglutination test indicated that most of the sera collected from 854 cattle in 9 prefectures of Japan, from Hokkaido to Okinawa, between 1988 and 1992 showed positive reactions, and the antibody titers ranged from below 4 to above 128. Seventy-seven percent of the sera showed titers of above 32. The antibody detection indicated that Japanese cattle had been infected with Erysipelothrix.
2.Seventy-nine isolates of Erysipelothrix species were obtained from 1,236 healthy cattle at slaughter houses in Yamagata, Miyagi, Tokyo and Nagasaki prefecture of Japan.
3.Serotyping results of the 79 Erysipelothrixisolates demonstrated that 43 isolates could be classified into 9 serovars, 1b,2,3,5,9,12,13,19 and
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21 but the remaining 36 isolates were untypable.
4.The pathogenicity tests demonstrated that 5(6.3%) and 21(25.3%) isolates of Erysipelothzix from cattle were lethal and induced clinical signs for mice, respectively. Four of the former 5 isolates induced localized or generalized urticarial lesions in swine. All the swine inoculated with 8 isolates virulent for mice developed fever and antibody titers. The results indicates that the bovine isolates are pathogenic.
5.PCR performed with the DNAs from the 79 bovine isolates demonstrated that these isolates were identified as 3 Erysipelothrix species, E.rhusiopathiae, E.tonsillarum and Erysipelothrix sp.strain 1. All the 36 isolates serologically untypable were identified as Erysipelothrix sp.strain 1. Genetic variations were recognized in the species of the same serovars. Erysipelotrhix sp.strain 1 is likely bovine specific. A correlation between pathogenicity and E.rhusiopathiae was observed. Identification of the species based on serovars and DNA homology among reference strains for serotyping was not always correlated with the results by the PCR. Less
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