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Evaluation of a live avirulent Escherichia coli vaccine for K88+, LT+ enterotoxigenic colibacillosis in weaned pigs.
1991
Francis D.H. | Willgohs J.A.
Live, avirulent Escherichia coli vaccine strains were constructed and tested for efficacy in preventing colibacillosis in 4-week-old pigs. Either or both of 2 plasmids were inserted into avirulent E coli strain G58-1 (0101:NM). These plasmids were pPMC4, which encodes for LTb subunits of heat-labile enterotoxin, and pDHF1, which encodes for K88ac fimbriae. Litter- and weight-matched pigs were removed from sows when they were 10 days old and vaccinated orally with the constructed strains or with G58-1 (negative control vaccine) when they were 2 weeks old and 5 days later. All pigs were challenge-inoculated with virulent E coli strain 3030-2 (0157:K88, LT+, STb+) 2 weeks after the first vaccination. Only 1 pig vaccinated with G58-1/pPMC4/pDHF1 developed diarrhea and none died following challenge inoculation. Seventeen of 31 control pigs developed diarrhea and 11 died. Of 18 pigs vaccinated with G58-1/pDHF1 then challenge-inoculated with the virulent strain, 5 developed diarrhea and 2 died. Fifteen of 18 litter- and weight-matched controls developed diarrhea and 8 died. When compared with G58-1 (negative control), G58-1/pPMC4 afforded no protection to pigs challenge-inoculated with 3030-2.
显示更多 [+] 显示较少 [-]Efficacy of a pseudorabies virus vaccine based on deletion mutant strain 783 that does not express thymidine kinase and glycoprotein I.
1991
Oirschot J.T. van | Moormann R.J.M. | Berns A.J.M. | Gielkens A.L.J.
The vaccine efficacy of a genetically engineered deletion mutant strain of pseudorabies virus, strain 783, was compared with that of the conventionally attenuated Bartha strain. Strain 783 has deletions in the genes coding for glycoprotein I and thymidine kinase. In experiment 1, which had a 3-month interval between vaccination and challenge exposure, strain 783 protected pigs significantly (P < 0.05) better against virulent virus challenge exposure than did the Bartha strain. The growth of pigs vaccinated with strain 783 was not arrested, whereas that of pigs vaccinated with the Bartha strain was arrested for 7 days. Of 8 pigs given strain 783, 4 were fully protected against challenge exposure; none of the pigs given strain Bartha was fully protected. In experiment 2, which had a 3-week interval between vaccination and challenge exposure, the growth of pigs vaccinated with strain 783 was arrested for 3.5 days, whereas that of pigs vaccinated with the Bartha strain was arrested for 6 days. In experiment 3, pigs with moderate titer of maternal antibodies were vaccinated twice IM or once intranasally with either strain 783 or Bartha and were challenge-exposed 3 months after vaccination. Pigs given strain 783 twice IM were significantly (P < 0.05) better protected than were the other pigs. They had growth arrest of only 6 days, compared with 9 days for pigs of other groups, and shed less virus after challenge exposure. Results of this study indicate that the vaccine based on the deletion mutant strain 783 is more efficacious than is the Bartha strain of pseudorabies virus.
显示更多 [+] 显示较少 [-]Isolation of a major form of pepsinogen from gastric mucosa of horses.
1991
Khittoo G. | Vermette L. | Nappert G. | Lariviere N.
In mammalian species studied previously, pepsinogen consisted of biochemically different groups of isozymogens. By use of gel filtration chromatography and electrophoresis, we isolated a predominant pepsinogen from the gastric mucosa of a horse. Peptide mapping with V8 protease revealed differences with its porcine homologue. However, porcine and equine pepsinogens, when activated to pepsin, had a similar pattern of activity when hemoglobin was used as substrate. Those results suggest that differences must exist in the primary structure of the pepsinogens of the 2 species.
显示更多 [+] 显示较少 [-]Preliminary survey of swine internal parasites at the sawdust fermentation floor system.
1991
Jang D.H. | Noh J.W. | Kang D.W.
Serotype and pathogenicity of Erysipelothrix rhusiopathiae isolated from the cases of acute septicemic swine erysipelas
1991
Baek, Y.S. | Kim, B.H. (Kyungpook National Univ., Taegu (Korea Republic). Coll. of Veterinary Medicine)
Clinical and bacteriological studies on infectious atrophic rhinitis of swine
1991
Kim, B.H. | Tak, R.B. (Kyungpook National Univ., Taegu (Korea Republic). Coll. of Veterinary Medicine) | Cho, G.J. (Korea Horse Affairs Association, Equine Health Laboratory) | Jang, H.K. (Rural Development Administration, Anyang (Korea Republic). Veterinary Research Institute)
Source of Ca++ and effect of adenosine triphosphate on the isolated renal artery of pig
1991
Nam, Y.J. | Kim, J.H. (Gyeongsang National Univ., Chinju (Korea Republic). Coll. of Veterinary Medicine)
Studies on the cloning gp50 and gp63 genes of Pseudorabies virus (Shope strain)
1991
Kweon, C.H. | An, S.H. | Song, J.Y. | Kim, B.H. | Lee, J.B. | Lee, J.C. (Rural Development Administration, Anyang (Korea Republic). Veterinary Research Institute) | Maeda, S. (Univ. of California, Davis (USA))
Serological survey on the leptospiral antibody in domestic animals in the area where human leptospirosis occurred
1991
Seo, I.S. (Seoul National Univ., Suwon (Korea Republic). Coll. of Veterinary Medicine)
Isolation and cultivation of swine encephalomyocarditis virus
1991
Ha, Y.K. | Yoon, S.M. | Jung, B.T. (Choongang Animal Disease Laboratory, Taejon (Korea Republic)) | Park, N.Y. | Lee, B.J. | Chung, C.Y. | Kee, H.Y. | Bae, S.Y. (Chonnam National Univ., Kwangju (Korea Republic). Coll. of Veterinary Medicine)