The development and evaluation of two tissue culture-grown Marek's disease challenge viruses.

Standardized challenge viruses are essential for the evaluation of Marek's disease (MD) vaccines with many MD challenge preparations consisting of lymphocytes or whole blood from infected birds. Virus present in these preparations is difficult to quantify by tissue culture assays and, therefore, the infectious bird dose and long-term storage viability cannot be assured. We report on the properties of two low-passage virulent Australian MD viruses, the Woodlands No. 1 strain and strain MPF 57. Both strains were isolated in chicken embryo kidney cultures and adapted to grow in chicken embryo fibroblast cultures for a maximum of 14 passages. Both strains could be readily assayed in tissue culture and produced titres of 10(3) to 10(4) 50% tissue culture infectious doses per ml (TCID(50)). Birds inoculated at three different doses were observed over 10 weeks, and tissues examined for gross and histological lesions, bursarbody weight ratios and the presence of viraemia. Tissue culture-grown preparations of both strains were only slightly less virulent than the original lymphocyte challenge material and produced similar pathological responses and around 80% death or gross lesions. From bursarbody weight ratios strain MPF 57 appeared to be more virulent than the Woodlands No. 1 strain.

[1]  R. Mehlotra Differentiation of pathogenic and non-pathogenic Entamoeba: has the question been answered? , 1998, Indian journal of gastroenterology : official journal of the Indian Society of Gastroenterology.

[2]  G. Tannock,et al.  Isolation of serotype 1 Marek's disease viruses from vaccinated Australian flocks. , 1995, Veterinary microbiology.

[3]  R. Good,et al.  Detection of the turkey pathogens Mycoplasma meleagridis and M. iowae by amplification of genes coding for rRNA , 1995, Journal of clinical microbiology.

[4]  G. Tannock,et al.  Some characteristics of a recent virulent isolate of Marek's disease virus. , 1994, Australian veterinary journal.

[5]  E. Smith,et al.  Detection of reticuloendotheliosis virus infection using the polymerase chain reaction. , 1993, Avian pathology : journal of the W.V.P.A.

[6]  I. Davidson,et al.  Polymerase chain reaction for differentiation between pathogenic and non-pathogenic serotype 1 Marek's disease viruses (MDV) and vaccine viruses of MDV-serotypes 2 and 3. , 1992, Journal of virological methods.

[7]  S. Ueda,et al.  Differentiation of oncogenic and nononcogenic strains of Marek's disease virus type 1 by using polymerase chain reaction DNA amplification. , 1992, Avian diseases.

[8]  R. Silva,et al.  Differentiation of pathogenic and non-pathogenic serotype 1 Marek's disease viruses (MDVs) by the polymerase chain reaction amplification of the tandem direct repeats within the MDV genome. , 1992, Avian diseases.

[9]  M. Noteborn,et al.  Detection of chicken anaemia virus by DNA hybridization and polymerase chain reaction. , 1992, Avian pathology : journal of the W.V.P.A.

[10]  R. Witter Attenuated revertant serotype 1 Marek's disease viruses: safety and protective efficacy. , 1991, Avian diseases.

[11]  J. McKimm-Breschkin,et al.  Isolation of very virulent Marek's disease viruses from vaccinated chickens in Australia. , 1990, Australian veterinary journal.

[12]  L. Lee,et al.  Monoclonal antibodies with specificity for three different serotypes of Marek's disease viruses in chickens. , 1983, Journal of immunology.

[13]  R. Witter Characteristics of Marek's disease viruses isolated from vaccinated commercial chicken flocks: association of viral pathotype with lymphoma frequency. , 1983, Avian diseases.

[14]  R. Witter Protection by attenuated and polyvalent vaccines against highly virulent strains of Marek's disease virus. , 1982, Avian pathology : journal of the W.V.P.A.

[15]  K. Ikuta,et al.  Marek's disease virus and herpesvirus of turkey noninfective to chickens, obtained by repeated in vitro passages. , 1979, Biken journal.

[16]  T. Bagust,et al.  Application of a flexible-film isolator for rearing specific pathogen-free chickens and investigating poultry pathogens. , 1979, Avian pathology : journal of the W.V.P.A.

[17]  P. C. Powell,et al.  Pathogenesis of Marek's disease. , 1976, International review of experimental pathology.

[18]  L. N. Payne,et al.  Pathogenesis of Marek's disease in chicks with and without maternal antibody. , 1973, Journal of the National Cancer Institute.

[19]  K. Schat,et al.  Control of Marek's disease in the Netherlands. I. Isolation of an avirulent Marek's disease virus (strain CVI 988) and its use in laboratory vaccination trials. , 1972, Avian diseases.

[20]  V. Dushkin,et al.  [Marek's disease]. , 1972, Voprosy virusologii.

[21]  W. Okazaki,et al.  The temporal relationship between vaccination with the herpesvirus of turkeys and challenge with virulent Marek's disease virus. , 1971, Avian diseases.

[22]  R. Chubb,et al.  The attenuation, with loss of oncogenicity, of the herpes-type virus of Marek's disease (strain HPRS-16) on passage in cell culture. , 1969, The Journal of general virology.