1887

Abstract

SUMMARY

The most reliable method of distinguishing strains of low virulence amongst a collection of stock strains of Newcastle disease virus (NDV) was by their failure to produce a good c.p.e. in monolayers of baby hamster kidney cells and of chick embryo cells. This method was of no help in identifying avirulent mutants that emerged in the Essex 70 strain of NDV following ultraviolet light, nitrous acid, hydroxylamine or -methyl-′-nitro--nitrosoguanidine (NTG) treatment. A marked reduction in the ability to kill developing chick embryos at 41 °C was a much more reliable indicator. Several of these temperature-sensitive mutants, most of which had been isolated from NTG-treated virus, were non-lethal for young chicks but they did have a depressive effect on their growth rate. The immunity produced by three of these mutants in chicks free of NDV antibody, but not in chicks possessing appreciable amounts of antibody, was probably even better than that produced by Hitchner B1 strain. All three mutants reverted to virulence during passage in chicks, although in no case were the revertants as virulent as the original Essex 70 strain. The virulent revertants obtained from one of the mutants had lost their temperature-sensitivity and proliferated in large numbers in the tissues of infected chicks. Those obtained from the other two had either not lost, or only partly lost, their temperature-sensitivity; they were found only in low concentrations in the tissues of infected chicks, their concentrations being little different from that found in the tissues of chicks infected with the mutants from which they were derived.

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/content/journal/jgv/10.1099/0022-1317-34-1-47
1977-01-01
2024-03-29
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References

  1. Allan W. H., Gough R. E. 1974; A standard haemagglutination test for Newcastle disease (1). A comparison of macro and micro methods. Veterinary Record 95:120–123
    [Google Scholar]
  2. Brandt N., Simon E. H. 1970; Preliminary characterization of temperature-sensitive mutants of Newcastle disease virus. Bacteriological Proceedings192
    [Google Scholar]
  3. Granoff A. 1961; Induction of Newcastle disease virus mutants with nitrous acid. Virology 13:402–408
    [Google Scholar]
  4. Macpherson I. A., Stoker M. G. P. 1962; Polyoma transformation of hamster cell clones – an investigation of genetic factors affecting cell competence. Virology 16:147–151
    [Google Scholar]
  5. Prebble O.T., Youngner J.S. 1972; Temperature-sensitive mutants isolated from L cells persistently infected with Newcastle disease virus. Journal of Virology 9:200–206
    [Google Scholar]
  6. Prebble O. T., Youngner J. S. 1973a; Temperature-sensitive defect of mutants isolated from L cells persistently infected with Newcastle disease virus. Journal of Virology 12:472–480
    [Google Scholar]
  7. Prebble O. T., Youngner J. S. 1973b; Selection of temperature-sensitive mutants during persistent infection; role in maintenance of persistent Newcastle disease virus infection of L cells. Journal of Virology 12:481–491
    [Google Scholar]
  8. Reeve P., Alexander D. J., Allan W. H. 1974; Derivation of an isolate of low virulence from the Essex 70 strain of Newcastle disease virus. Veterinary Record 94:38–41
    [Google Scholar]
  9. Reeve P., Poste G. 1971; Studies on the cytopathogenicity of Newcastle disease virus: relation between virulence, polykaryocytosis and plaque size. Journal of General Virology 11:17–24
    [Google Scholar]
  10. Reeve P., Poste G., Alexander D. J., Pope G. 1972; Studies on the cytopathic effects of Newcastle disease virus: cell surface changes. Journal of General Virology 15:219–225
    [Google Scholar]
  11. Thiry L. 1963; Chemical mutagenesis of Newcastle disease virus. Virology 19:225–236
    [Google Scholar]
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