Isolates of infectious bursal disease virus (IBDV) were obtained from domestic poultry in New Zealand in 1997 and 1998. An in-vivo pathogenicity study carried out in specific pathogen free (SPF) chickens demonstrated ...
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Isolates of infectious bursal disease virus (IBDV) were obtained from domestic poultry in New Zealand in 1997 and 1998. An in-vivo pathogenicity study carried out in specific pathogen free (SPF) chickens demonstrated the low virulence of one of the virus isolates. The nucleotide sequences of the hypervariable region of the VP2 gene of two isolates were determined and compared with published sequences of strains from other countries. The deduced amino acid sequence of the two New Zealand IBDV isolates showed 100% identity with each other, suggesting that little genetic drift had occurred. Phylogenetic analysis showed that the New Zealand isolates were more closely related to two attenuated IBDV strains (Cu1 and PBG98) than to classical (STC and 52/70), very virulent (DV86), variant (variant E) or Australian (002-73) strains. The results support the hypothesis that an attenuated strain of the virus was inadvertently introduced into the NZ poultry population in 1993.
The genome segments of infectious bursal disease viruses (IBDV) in the bursa of Fabricius from experimently infected chickens or field samples were detected by tissue print hybridization;(TPH) with subsequent reverse ...
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The genome segments of infectious bursal disease viruses (IBDV) in the bursa of Fabricius from experimently infected chickens or field samples were detected by tissue print hybridization;(TPH) with subsequent reverse transcriptase (RT)- polymerase chain reaction (PCR). Bursae were imprinted onto nylon membrane and then hybridized with a cloned digoxigenin (DIG)-labeled cDNA probe. Tissue prints on nylon membrane were readily distinguished from control prints by color development and differences in signal intensity. In order to verify the TPH test, RT-PCR was used to amplify a 643-base pair fragment on the VP2 gene of IBDV in me bursa of Fabricius. With all isolates, a cDNA fragment of 643 bp long was generated as expected and further confirmed the specificity of TPH. Our results suggest that a large number of field samples or selected tissues can be rapidly examined by TPH technique when combined with a cloned DIG-labeled CDNA probe. (C) 2000 Harcourt Publishers Ltd.
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