title: Pathogenicity, tissue distribution, shedding and environmental detection of two strains of IBDV following infection of chickens at 0 and 14 days of age.
abstract: Infectious bursal disease virus (IBDV) is endemic to most poultry-producing countries worldwide. Immunosuppressive classical and variant IBDV strains endemic to Australia are genetically distinct from other international strains. We report the results of infection experiments with Australian classical strain 06/95 and variant strain 02/95 in SPF chickens. We tested the effects of strain and age of infection on bursal atrophy, viral RNA (vRNA) load in bursa of Fabricius (bursa), spleen, thymus, caecal tonsils, faeces, litter and exhaust dust as determined by real-time reverse transcriptase polymerase chain reaction. The two IBDV strains did not differ in the degree of bursal atrophy induced, lymphoid organ distribution and faecal shedding but variant strain 02/95 induced a greater antibody response to the infection than classical strain 06/95 which was associated with a more rapid decline in IBDV vRNA genome copy number (VCN) in lymphoid organs and faeces. Infection at 14 days of age induced greater bursal atrophy and higher vRNA copy number in lymphoid tissues than infection on the day of hatching, indicating true age susceptibility independent of maternal antibody (Mab) status. The direction of the association between rankings for IBDV vRNA load in bursa and relative bursal weight changed from positive at 3 and 6 days post-infection to negative at 28 days post-infection. Intra-tracheal administration of dust collected from chickens infected with IBDV resulted in successful transmission of IBDV. IBDV vRNA was detected successfully at high levels in the environmental litter and dust samples.
authors: a Animal Science, School of Environmental and Rural Science , University of New England , Armidale , NSW , Australia.
authors: J M K G K
authors: JMKGK
authors: Jayasundara
authors: a Animal Science, School of Environmental and Rural Science , University of New England , Armidale , NSW , Australia.
authors: S W
authors: SW
authors: Walkden-Brown
authors: b Molecular and Cellular Biology , School of Science and Technology, University of New England , Armidale , NSW , Australia.
authors: M E
authors: ME
authors: Katz
authors: a Animal Science, School of Environmental and Rural Science , University of New England , Armidale , NSW , Australia.
authors: A F M F
authors: AFMF
authors: Islam
authors: a Animal Science, School of Environmental and Rural Science , University of New England , Armidale , NSW , Australia.
authors: K G
authors: KG
authors: Renz
authors: c FD McMaster Laboratory, Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Armidale , NSW , Australia.
authors: J
authors: J
authors: McNally
authors: c FD McMaster Laboratory, Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Armidale , NSW , Australia.
authors: P W
authors: PW
authors: Hunt
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D018175:Birnaviridae Infections / Q000662:veterinary* / Q000821:virology; D002060:Bursa of Fabricius / Q000821:virology; D002645:Chickens / Q000821:virology*; D005260:Female; D007243:Infectious bursal disease virus / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity* / Q000502:physiology; D008221:Lymphoid Tissue / Q000821:virology; D008297:Male; D011201:Poultry Diseases / Q000821:virology*; D012367:RNA, Viral / Q000032:analysis; D013047:Specific Pathogen-Free Organisms; D013154:Spleen / Q000821:virology; D014018:Tissue Distribution; D019562:Viral Load / Q000662:veterinary; D014774:Virulence
chemical_list: D000914:Antibodies, Viral; D012367:RNA, Viral
keywords: Infectious bursal disease virus; bursa; classical and variant strains; poultry house litter and dust; serological response; serotype; shedding; tissue distribution; virus quantification