Browsing by Author "Temesgen Ayana"

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    Isolation and Molecular Characterization of Mycobacteria From Infected Cattle in and Around Bako, Western Oromia, Ethiopia
    (Addis Ababa University, 2010-06) Temesgen Ayana; Tesfaye Sisay; Gobena Ameni
    A cross-sectional study was conducted on 858 heads of cattle (371 recruited from Bako Agricultural Research Center, BARC and 487 from Bako municipal abattoir) from October 2009 to April 2010 to estimate the prevalence of bovine tuberculosis (BTB) and characterize its causative agents. To this effect, comparative intradermal tuberculin (ClOT) test, post mortem examination, bacteriological culturing, genus typing using multiplex polymerase chain reaction (PCR) were applied. At the cut-off point of ~4mm (recommendation of the Office des International Epizooties, OlE), animal prevalence of BTB was 1.3%. Re-analysis of the same data using the newly defined cut-off point of >2mm gave a prevalence of 4.6%. There was a highly significant difference (P=O.OOO) in prevalence estimated using the two cut-off points in zebu cattle. The prevalence was significantly associated with age (P=0.012) and origin (P=0.04) of the animal. On the other hand, the prevalence was 9.3% (46/492) in cattle slaughtered at Bako abattoir. Lesions were more frequent and severe in the mesenteric (60.9%), retropharyngeal (17.4%), and bronchial (17.4%) lymph nodes of slaughtered cattle. Culture positivity in suspicious tissues was 32.6% (29/89) although only 69% (20/29) were confirmed to be acid-last bacilli (AFB) by Ziehl Neelsen staining. Of the 20 AFB positive isolates, 17 were characterized by multiplex PCR and almost all (94%) of the isolates showed signal for the Genus Mycobacterium. Nevertheless, none of these isolates showed signal for the Mycobacterium Tuberculosis complex as revealed by multiplexer. Therefore, further identification and characterization of these isolates should be done. Furthermore, the pathogenicity of these mycobacteria in livestock requires further investigation. Key words: Bovine tuberculosis, Prevalence, Pathology, Culturing, Molecular typing, Mycobacteria, Balm, Ethiopia.