Mycobacterium bovis strains isolated from tuberculosis (TB) lesions from 1138 cattle slaughtered at Kombolcha abattoir in north eastern Ethiopia were characterised. Detailed postmortem examination, bacteriological culturing, regions of difference PCR and spoligotyping were used. At least one TB lesion was observed in 57 (5 per cent) of the cattle, of which 27 (47 per cent) yielded mycobacteria isolates. Of the 27 isolates, 25 were identified as M bovis and two as Mycobacterium tuberculosis. The M bovis isolates were grouped into six clusters of strains, and the M tuberculosis isolates were typified to one strain only with the reference SIT262. Three clusters of previously unreported M bovis strains were identified and reported to the Mycobacterium bovis spoligotype database. They were designated the reference numbers SB1490, SB1491 and SB1492.

Cells (CD3+ T cell and CD68+ macrophages), cytokines (IFN-γ+ and TNF-α+) and effector molecule (iNOS+) responses were evaluated in the lymph nodes and tissue of cattle naturally infected with Mycobacterium bovis. Detailed post mortem and immunohistochemical examinations of lesions were performed on 16 cows positive for single intradermal cervical comparative tuberculin (SICCT) test which were identified from dairy farms located around the Addis Ababa City. The severity of the gross lesion was significantly higher (p=0.003) in M. bovis culture positive (n=12) cows than in culture negative (n=4). Immunohistochemical techniques showed that in culture positive cows, the mean immunolabeling fraction of CD3+ T cells decreased as the stage of granuloma increased from stage I to stage IV (p<0.001). In contrast, the immunolabelling fraction of CD68+ macrophages, IFN-γ+, TNF-α+ and iNOS+ increased from stage I to stage IV (p< 0.001). In culture negative cows, early stages showed a significantly higher fraction of CD68+ macrophages (p=0.03) and iNOS+ (p=0.007) when compared to culture positive cows. Similarly, at advanced granuloma stages, culture negative cows demonstrated significantly higher mean proportions of CD3+ T cells (p< 0.001) compared to culture positive cows. Thus, this study demonstrates that following natural infection of cows with M. bovis, as the stage of granuloma increases from stage I to stage IV, the immunolabelling fraction of CD3+ cells decreases while the immunolabeling fraction of CD68+ macrophages, IFN-γ+, TNF-α+ and iNOS+ increases.

We investigated the causes of mortality of the Arabian gazelle (Gazella arabica) based on the necropsy records of 1218 captive animals at King Khalid Wildlife Research Centre, Saudi Arabia, from 1988 to 2011. The largest number of deaths was attributed to trauma (391, 32.1%). Trauma was subdivided into the following three categories: collisions with fences (144, 11.8%); predator activity (91, 7.5%), and exhibit-mate aggression (156, 12.8%). Respiratory infection was another important cause of mortality, accounting for 186 (15.3%) deaths. Respiratory infection was more prevalent during the winter season (November to March). Other causes of death included gastrointestinal diseases, such as clostridiosis and salmonellosis (108, 8.9%). Maternal neglect (104, 8.5%), chronic renal fibrosis (34, 2.8%), and stress-related pathologies (35, 2.9%), in particular, capture myopathy, were also important causes of mortality. Here, the importance of these findings for improvement of the captive management of this vulnerable Arabian species is discussed, and for the first time, salmonellosis in Arabian gazelles is reported.

33Cellular (CD3+ T cell and CD68+ macrophages), cytokines (IFN-+ and TNF-α+) and 34 effector molecule (iNOS+) responses were evaluated in the lymph nodes and tissue 35 of cattle naturally infected with Mycobacterium bovis. Detailed post mortem and 36 immunonohistochemical examinations of lesions were performed on 16 cows 37 positive for single intradermal cervical comparative tuberculin test (SICCTT) and 38 identified from dairy farms located around the Addis Ababa City. The severity of the 39 gross lesion was significantly higher (p=0.003) in M. bovis culture positive (n=12) 40 cows than in culture negative (n=4). Immunohistochemical techniques showed that 41 the mean percentage labelling of CD3+ T cells decreased as the stage of granuloma 42 increased from stage I to stage IV in culture positive cows (p<0.001). On the other 43 hand, the proportional fraction of CD68+ macrophages and the concentrations of 44 IFN-+, TNF-α+ and iNOS+ increased significantly from stage I to stage IV (p< 45 0.001) in culture positive cows. At the early stage of the granuloma, the culture 46 negative cows showed significantly higher mean proportions of CD68+ macrophages 47 (p=0.03) as well as the concentrations of iNOS+ (p=0.007) compared to culture 48 positive cows. Similarly, at advanced granuloma stages, culture negative cows 49 demonstrated significantly higher mean proportions of CD3+ T cells (p< 0.001) 50 compared to culture positive cows. Thus, the present study demonstrated that 51 following natural infection of cows with M. bovis, as the stage of granuloma 52 increases from stage I to stage IV, the proportion of CD3+ cells decreases while the 53 immunolabeling fraction of CD68+ macrophages, IFN-+, TNF-α and iNOS+ 54 increases.55 3