title: Effect of bursal cell number on the pathogenesis of infectious bursal disease in chickens.
abstract: The pathogenesis of infectious bursal disease (IBD) in chickens neonatally chemically bursectomized (CB) by cyclophosphamide and subsequently inoculated with various numbers of bursal cells was examined. CB chickens inoculated with at least 62.5 X 10(6) bursal cells were as susceptible to IBD clinical manifestations (as determined by gross and microscopic evaluation of bursal tissues, virus recovery from spleen, and antibody titer) as intact chickens following inoculation with virus at 5 weeks of age. In contrast, CB chickens inoculated with 2.5 X 10(6) or fewer bursal cells were refractory to the IBD clinical manifestations compared with intact chickens or CB chickens inoculated with 62.5 X 10(6) or more bursal cells. Results from this study suggest that the availability of a large number of bursal cells is an essential factor in the development of IBD.
authors.affiliation: U.S. Department of Agriculture-Agricultural Research Service, East Lansing, Michigan 48823.
authors.forename: N M
authors.initials: NM
authors.lastname: Ismail
authors.forename: A M
authors.initials: AM
authors.lastname: Fadly
authors.forename: T S
authors.initials: TS
authors.lastname: Chang
mesh_terms: D000818:Animals; D002060:Bursa of Fabricius / Q000382:microbiology / Q000473:pathology*; D002452:Cell Count; D002642:Chick Embryo; D002645:Chickens; D003520:Cyclophosphamide; D004198:Disease Susceptibility; D007243:Infectious bursal disease virus / Q000502:physiology; D009929:Organ Size; D011201:Poultry Diseases / Q000209:etiology* / Q000382:microbiology; D012088:Reoviridae Infections / Q000209:etiology / Q000382:microbiology / Q000662:veterinary*; D013047:Specific Pathogen-Free Organisms; D014779:Virus Replication
chemical_list: D003520:Cyclophosphamide