title: Pasteurella multocida infection in the chicken embryo.
abstract: Pasteurella multocida infection in embryonated chicken eggs was studied by chorio-allantoic membrane inoculation. Strain differences were demonstrated in terms of lesion severity and time to death, especially during the first 24 h post-inoculation. A strain of low virulence gave a clear dose response but more virulent strains did not. Comparable results were obtained by infecting 6-week-old chickens. The main lesions in inoculated embryos appeared as severe vascular involvement of the entire embryo and feather tracts, thickening of the chorio-allantoic membrane, and enlargement and congestion of the yolk sac. The bacteria were demonstrated by transmission electron microscopy, either extracellularly or multiplying intracellularly in hepatocytes, heart tissue, and in the hyperplastic layer of the chorio-allantoic membrane, with resulting damage to the cellular organelles, and severe tissue changes.
authors.affiliation: Nippon Veterinary and Animal Science University, Department of Veterinary Microbiology, Tokyo, Japan.
authors.forename: R S
authors.initials: RS
authors.lastname: Ibrahim
authors.forename: T
authors.initials: T
authors.lastname: Sawada
authors.forename: S
authors.initials: S
authors.lastname: el-Ballal
authors.forename: M
authors.initials: M
authors.lastname: Shahata
authors.forename: T
authors.initials: T
authors.lastname: Yoshida
authors.forename: Y
authors.initials: Y
authors.lastname: Kataoka
mesh_terms: D000482:Allantois / Q000196:embryology / Q000382:microbiology / Q000473:pathology; D000818:Animals; D001808:Blood Vessels / Q000196:embryology / Q000382:microbiology / Q000473:pathology; D002467:Cell Nucleus / Q000382:microbiology / Q000473:pathology; D002642:Chick Embryo / Q000382:microbiology* / Q000473:pathology; D004475:Ectoderm / Q000382:microbiology / Q000473:pathology; D006321:Heart / Q000196:embryology / Q000382:microbiology; D008099:Liver / Q000196:embryology / Q000382:microbiology / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D010326:Pasteurella Infections / Q000196:embryology* / Q000473:pathology / Q000662:veterinary; D016979:Pasteurella multocida / Q000302:isolation & purification / Q000472:pathogenicity* / Q000648:ultrastructure; D014774:Virulence