A cross-sectional study was conducted from December 2016 to May 2017 in and around Sebeta town with the aim of assessing the prevalence of mastitis, isolation of aerobic bacterial and fungal causal agents and assessing antimicrobial resistance pattern of isolated Staphylococcus species in dairy cows. From a total of 383 dairy cows, 220 (57.4%) were found to be positive for mastitis of which 10.4% were affected by clinical mastitis and 47% by subclinical mastitis. Mastitis was more likely to occur in cows above 8 years of age (OR = 16.9, 95% CI = 7.8-36.00) and in those cows washed by hand before milking (OR =7.8, 95% CI = 4.2-14.6) as compared to those subjected to udder washing and drying using towels. Staphylococcus aureus was the most frequently isolated bacterial species (25%) followed by Streptococcus agalactiae (12.3%) and coagulase negative Staphylococcus species (10.5%). Yarrowia lipolytica (10.9%) and Candida etchellsii (7.3%) were the major yeast species isolated, while Aspergillus (6.8%), Mucor (5.9%), Penicillium (3.6%) and Fusarium (3.6%) were the major filamentous fungi species identified from the cultured milk samples. The results of antimicrobial susceptibility testing revealed that the isolated Staphylococcus species were highly resistant to penicillin G (93.1%) and oxytetracycline (79.3%) but were susceptible to vancomycin (100%), sulphamethoxazole/trimethoprim (96.6%), ampicillin (89.7%) and erythromycin (86.2%). It could be concluded that bovine mastitis is a major challenge to the dairy producers in and around Sebeta towns. Appropriate control and preventative measures must be instituted and dairy farmers and workers must be trained on proper milking and hygiene practices in order to reduce the prevalence of mastitis in this region. The penicillin resistant S. aureus could be a source of serious infection in humans as well and hence comprehensive studies including molecular characteristics of drug resistance gene of S. aureus especially of methicillin-resistant should be conducted as farm animals, primarily dairy cattle might serves as a reservoir of infection for humans. In 2% of the cases, only fungal species were identified as causes of mastitis, hence further investigation regarding their pathogenicity and contribution to bovine mastitis is needed.

Contagious bovine pleuropneumonia (CBPP) was recognised on Bako Agricultural Research Farm, in the Oromia Region of Ethiopia, for the first time on 5 May 2011. The outbreak was investigated by combining recognition of clinical signs, post-mortem examination, mycoplasma isolation and serological testing using competitive enzymelinked immunosorbent assay (c-ELISA). The clinical cases were monitored for eight months; sick animals were treated with a range of antibiotics and isolated if necessary. The outbreak of CBPP was confirmed both bacteriologically and serologically and had spread to almost the entire herd (96.7%) within the eight-month observation period. Of the animals that recovered after antibiotic treatment, 12.3% fell sick again, showed typical signs of CBPP and were considered to be carriers. The role of treatment in the prevention of the spread of CBPP was minimal. Newly purchased animals that were not tested and quarantined before being introduced onto the farm were suspected to have been the most probable source of infection.

A cross-sectional study was conducted between November 2015 and March 2016 on apparently healthy slaughtered sheep and goats, and clean knife at Luna and Elfora export abattoirs located at Modjo and Bishoftu towns to estimate the prevalence of Salmonella in sheep and goats, to assess the hygienic condition of flaying knife, and to isolate and identify the prevalent Salmonella sub-species. A total of 525 samples consisting of cecum (n=122), liver (n=122), mesenteric lymph nodes (n=122), abdominal muscle (n=122) from 44 sheep and 78 goats and 37 pooled knife samples were collected. The samples were examined for the presence of Salmonella following the conventional techniques of ISO standard and using OMNILOG bacterial identification system, GEN III microplate for confirmation and sub species identification. From the total of 122 animals examined, 21 (17.21%) were positive of which 12 (9.83%) were sheep and 9 (7.38%) were goats, and none of the samples from pooled knife swabs were positive for Salmonella. Statistically significant difference (P=0.04) in the prevalence of Salmonella was observed between the two species. The frequency of isolation was 10 (3.89%) and 11 (4.10%) from Luna and Elfora abattoirs, respectively. As a result, there was no significant difference (P =0.884) in the prevalence of Salmonella isolation between the two abattoirs. Of the total 488 tissue samples examined from apparently healthy slaughtered sheep and goat, 21 (4.3%) samples were Salmonella positive. Salmonella was isolated from 6.56% mesenteric lymph nodes, 5.73% cecum, 4.09% liver and 0.82% abdominal muscle samples. However, there was no significant difference between tissues (P=0.13). From the 21 isolated Salmonella species, 20 of them were confirmed to be the pathogenic Salmonella enterica subspp. enterica and 1 isolate was the non-pathogenic Salmonella enterica subspp. salamae. The results of this study showed the potential risk of sheep and goats as sources of pathogen for humans in the study area. These findings stressed the need for implementation of preventing close contact of offal and carcass during evisceration.

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