Author
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King, Daniel |
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WAKAMATSU, NOBUKO - UNIV OF GA - ATHENS, GA |
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PEETERS, BEN P. - LELYSTAD, THE NETHERLANDS |
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SAMAL, SIBA - UNIV OF MD-COLLEGE PK,MD |
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BROWN, CORRIE - UNIV OF GA -ATHENS, GA |
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Seal, Bruce |
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Submitted to: American Veterinary Medical Association Abstract
Publication Type: Abstract Only Publication Acceptance Date: 1/15/2003 Publication Date: 7/19/2003 Citation: KING, D.J., WAKAMATSU, N., PEETERS, B.H., SAMAL, S.K., BROWN, C.C., SEAL, B.S. THE EFFECT OF MUTATIONS IN NEWCASTLE DISEASE VIRUS STRAINS LASOTA AND BEAUDETTE C ON THEIR PATHOGENICITY IN CHICKENS. WORLD VETERINARY POULTRY ASSOCIATION. 2003. Interpretive Summary: Technical Abstract: Virulence differences among Newcastle disease virus (NDV) isolates are based on the results of chicken inoculation utilizing standardized pathogenicity test procedures. Results of those tests are used to classify viruses as high, moderate, or low virulence and are the basis for imposing trade restrictions when viruses of moderate and high virulence are recovered from poultry. The amino acid sequence at the cleavage activation site of the fusion protein of NDV is a molecularly defined virulence marker, but it is widely recognized that other presently undefined factors contribute to the virulence differences among isolates. To extend the understanding of virus factors that contribute to virus virulence, mutations were created in selected genes of the low virulence LaSota and virulent Beaudette C strains to assess the role of those changes on virus pathogenicity in chickens. Compared to the wild-type parent strains, the LaSota virus with a fusion cleavage site mutated to the virulent sequence had increased chicken virulence and mutations in the phosphoprotein or hemagglutinin-neuraminidase genes of Beaudette C had decreased virulence in preliminary tests. Completion of pathogenicity testing of the virus mutants and their parent strains is in process. |
