title: Isolation, identification, and pathogenicity of two field strains of infectious bursal disease virus.
abstract: Using a sentinel bird approach, two field isolates of infectious bursal disease virus (IBDV) were isolated from broiler farms in two major broiler-producing areas of the state of Georgia. These farms had a history of subclinical IBD associated with respiratory problems and poor performance. Isolates designated as U-28 and 3212 were isolated using specific-pathogen-free chicken embryos and chicken embryo bursal cells. These isolates were identified by means of agar gel precipitation and virus-neutralization tests, direct immunofluorescence, histopathology, and electron microscopy. Isolates U-28 and 3212 appear to differ in antigenicity and pathogenicity from previously known serotype I IBDV isolates. In evaluating the extent of bursal damage caused by these field isolates, an association was found between the bursa of Fabricius/body weight index, histopathology scoring of atrophy, and morphometric analysis of the total follicle area.
authors.affiliation: Department of Avian Medicine, College of Veterinary Medicine, University of Geoggia, Athens 30602.
authors.forename: A G
authors.initials: AG
authors.lastname: Rosales
authors.forename: P
authors.initials: P
authors.lastname: Villegas
authors.forename: P D
authors.initials: PD
authors.lastname: Lukert
authors.forename: O J
authors.initials: OJ
authors.lastname: Fletcher
authors.forename: M A
authors.initials: MA
authors.lastname: Mohamed
authors.forename: J
authors.initials: J
authors.lastname: Brown
mesh_terms: D000818:Animals; D002060:Bursa of Fabricius / Q000473:pathology; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens; D005455:Fluorescent Antibody Technique; D005845:Georgia; D005779:Immunodiffusion; D007243:Infectious bursal disease virus / Q000302:isolation & purification* / Q000472:pathogenicity / Q000648:ultrastructure; D008099:Liver / Q000473:pathology; D008854:Microscopy, Electron; D009500:Neutralization Tests; D011201:Poultry Diseases / Q000382:microbiology*; D012087:Reoviridae / Q000302:isolation & purification*; D012088:Reoviridae Infections / Q000382:microbiology / Q000662:veterinary*; D013047:Specific Pathogen-Free Organisms; D014611:Vaccination / Q000662:veterinary