الفهرس | Only 14 pages are availabe for public view |
Abstract Bovine tuberculosis caused by Mycobacterium bovis is a chronic and zoonotic disease. Although skin intradermal test is the standard method for the diagnosis of tuberculosis in live bovine, it doesn’t fulfill all criteria necessary to identify all infected animals rendering diagnosis of bovine tuberculosis extremely challenging The present study was planned accordingly to study the efficacy of tuberculin test, compared with serodiagnosis by enzyme linked immunosorbent assay (ELISA) and in-vitro gamma-interferon assay in diagnosis of bovine tuberculosis..Out of 243 cattle from a bovine tuberculosis endemic farm at El minufiya governorate tested by single intradermal cervical tuberculin test (SICTT) by using bovine purified protein derivatives (b.PPD),159 positive reactors were slaughtered and tuberculosis was confirmed by postmortem examination and by culture isolation method (CIM).A total of 124 animals (78%) showed visible tuberculous lesions ,including generalized 7 (4.4%),head 19 (12 %) ,respiratory 58 (36.4%) and digestive lesion40(25.2%),while the remaining 35 cattle (22%) showed non visible lesions(NVL).Bacteriological examination of different tissues collected from tuberculin positive animals revealed 112(70.4%) Mycobacterium bovis isolates in addition to 9 (5.66%) unidentified mycobacteria ,of which 7 were slow growers and 2 were rapid growers.Isolation of Mycobacterium bovis from lesions varied according to the type of examined tuberculous lesions and ranged from 100%,91.3% ,82.5%,79% and 22% in generalized, respiratory, digestive, head and NVL respectively.With exception of generalized tuberculosis , serodiagnosis of bovine tuberculosis by ELISA showed lesser sensitivity in detection of tuberculin reactors if compared with SICTT, meanwhile the whole blood gamma-interferon assay showed higher sensitivity in retesting suspected and negative animals by SICTT. Antibiotic sensitivity testing of Mycobacterium bovis isolates by Microscopic Observation Broth Drug susceptibility test (MODS) showed that 88.3% of Mycobacterium bovis isolates was sensitive to rifampicin,76.6% was sensitive to ethambutol,53.3% was sensitive to isoniazid and 45% sensitive to streptomycin. |