title: Cattle husbandry in Ethiopia is a predominant factor affecting the pathology of bovine tuberculosis and gamma interferon responses to mycobacterial antigens.
abstract: Bovine tuberculosis is a major economic problem and a potential public health risk. Improved diagnostics like the gamma interferon (IFN-gamma) test with ESAT6 and/or CFP10 could contribute to the control program. We assessed IFN-gamma responses in zebu (Ethiopian Arsi breed) and Holstein cattle kept indoors or in a pasture to tuberculin purified protein derivative (PPD) and an ESAT6-CFP10 protein cocktail. Furthermore, the intensity and distribution of pathology of bovine tuberculosis were compared between the two breeds. Our data demonstrated significantly (all P < 0.02) higher IFN-gamma responses to avian PPD, bovine PPD, and the ESAT6-CFP10 protein cocktail in Holstein than in zebu cattle, while lesion severities in infected animals and tuberculin skin test responses did not differ significantly (P > 0.05) between the two breeds. Holstein cattle that were kept indoors produced significantly (all P < 0.01) higher IFN-gamma levels in response to avian PPD, bovine PPD, and the ESAT6-CFP10 protein cocktail than did Holstein cattle kept in a pasture. Moreover, lesion severity was significantly higher in Holstein cattle kept indoors (P = 0.001) than in those kept in the pasture. Lesions were localized predominantly in the digestive tract in cattle kept in a pasture, while they were localized in the respiratory tract in cattle kept indoors. In conclusion, in Holstein cattle, husbandry was a dominant factor influencing the severity of tuberculosis lesions and IFN-gamma responses to mycobacterial antigens compared to breed. A difference in the cellular immune response between zebu and Holstein cattle was observed, while tuberculosis lesion severities were identical in the two breeds, when both were kept in a pasture.
authors.affiliation: Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia. gobenaameni@yahoo.com
authors.forename: Gobena
authors.initials: G
authors.lastname: Ameni
authors.forename: Abraham
authors.initials: A
authors.lastname: Aseffa
authors.forename: Howard
authors.initials: H
authors.lastname: Engers
authors.forename: Douglas
authors.initials: D
authors.lastname: Young
authors.forename: Glyn
authors.initials: G
authors.lastname: Hewinson
authors.forename: Martin
authors.initials: M
authors.lastname: Vordermeier
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D000942:Antigens, Bacterial / Q000145:classification / Q000276:immunology*; D002417:Cattle; D005002:Ethiopia / Q000453:epidemiology; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000276:immunology*; D009163:Mycobacterium bovis / Q000276:immunology*; D014374:Tuberculin Test / Q000662:veterinary; D014380:Tuberculosis, Bovine / Q000209:etiology / Q000473:pathology*
chemical_list: D000942:Antigens, Bacterial; D007371:Interferon-gamma