title: Isolation of Mycobacterium bovis from the respiratory tracts of skin test-negative cattle.
abstract: Mycobacterium bovis was isolated from the respiratory tracts of three cattle which registered negative to tuberculin testing; no tuberculous lesions were found and the culture of lymph nodes and other tissues proved negative. One animal was from a group of five calves which had been inoculated intranasally with M bovis, and the organism was recovered once only from nasal mucus sampled 100 days after inoculation. The second animal had had contact with experimentally infected cattle which were excreting M bovis and the third was from a commercial farm. The results of ELISAS for antimycobacterial antibodies and interferon-gamma, and of lymphocyte transformation assays are presented. The animals' immune responses provided evidence that each of them had been challenged.
authors.affiliation: Veterinary Research Laboratories, Stormont, Belfast.
authors.forename: S D
authors.initials: SD
authors.lastname: Neill
authors.forename: J
authors.initials: J
authors.lastname: Hanna
authors.forename: D P
authors.initials: DP
authors.lastname: Mackie
authors.forename: T G
authors.initials: TG
authors.lastname: Bryson
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D002417:Cattle; D007371:Interferon-gamma / Q000097:blood; D008297:Male; D009163:Mycobacterium bovis / Q000276:immunology / Q000302:isolation & purification*; D009297:Nasal Mucosa / Q000382:microbiology*; D010743:Phospholipids / Q000276:immunology; D014373:Tuberculin / Q000276:immunology; D014374:Tuberculin Test / Q000662:veterinary; D014380:Tuberculosis, Bovine / Q000175:diagnosis*
chemical_list: D000907:Antibodies, Bacterial; D010743:Phospholipids; D014373:Tuberculin; D007371:Interferon-gamma