Characterisation of New Zealand isolates of infectious bursal disease virus.
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.
Chai
Y F
YF
Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand. yfchai@singnet.com.sg
Christensen
N H
NH
Wilks
C R
CR
Meers
J
J
D000595:Amino Acid Sequence; D000818:Animals; D018175:Birnaviridae Infections / Q000662:veterinary* / Q000821:virology; D002645:Chickens; D018076:DNA, Complementary; D007243:Infectious bursal disease virus / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D008969:Molecular Sequence Data; D009520:New Zealand; D011201:Poultry Diseases / Q000821:virology*; D012367:RNA, Viral / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D015678:Viral Structural Proteins / Q000737:chemistry / Q000235:genetics; D014774:Virulence
D018076:DNA, Complementary; D012367:RNA, Viral; C082513:VP2 protein, infectious bursal disease virus; D015678:Viral Structural Proteins