title: Colonization of the nasal passages of calves with Pasteurella haemolytica serotype 1 and regeneration of colonization after experimentally induced viral infection of the respiratory tract.
abstract: Healthy nonstressed calves were inoculated intranasally with or subjected to aerosol exposure to Pasteurella haemolytica serotype 1. Only 4 of 28 calves harbored the bacterium in enough numbers to be isolated from the nasal passages for more than 7 days. After apparent clearing from the nasal passages, 8 calves were inoculated intranasally with infectious bovine rhinotracheitis virus; 2 of these calves shed the P haemolytica during clinical illness due to the virus. The remaining 20 calves were aerosol-exposed to parainfluenza-3 virus; 6 of these calves shed P haemolytica during clinical illness due to the parainfluenza-3 virus.
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D007668:Kidney; D009297:Nasal Mucosa / Q000382:microbiology*; D010325:Pasteurella / Q000145:classification / Q000254:growth & development*; D010326:Pasteurella Infections / Q000150:complications / Q000503:physiopathology / Q000662:veterinary*; D012141:Respiratory Tract Infections / Q000503:physiopathology / Q000662:veterinary*; D012703:Serotyping; D014777:Virus Diseases / Q000150:complications / Q000503:physiopathology / Q000662:veterinary*