ISOLATION, IDENTIFICATION AND ANTIMICROBIAL SUSCEPTIBILITY PATTERNS OF SALMONELLA FROM DIARRHIEC CALVES IN HARAMAYA DISTRICT OF DAIRY FARM, EAST HARARGHE ZONE, ETHIOPIA

Abstract

Calf diarrhea is a major economic concern in bovine industry all around the world. Thus, this study was conducted to isolate, identify and test for the antimicrobial susceptibility patterns of Salmonella spp isolated from diarrheic calves in selected dairy farms. A cross-sectional study was conducted in dairy farms in Haramaya district dairy farms from April-October 2021 with a purposive sampling method. Fecal samples were directly collected from the rectum of diarrheic calves in order to identify Salmonella based on their cultural and biochemical characteristics. Potential risk factors associated with calf diarrhea was assessed using questionnaire. The antimicrobial susceptibility test was performed using agar disc diffusion method with standard antimicrobial discs. A total of 98 fecal samples were examined for the isolation of Salmonella, of which 31 (31.6%) were positive. The prevalence tends to be higher in female calves 19/55 (34.5%) than males 12/43 (27.9%); in calves aged greater than 3months 21/54 (38.9%) compared with the youngest 10/44 (22.7%); in calves under medium sized farm 11/33 (33.3%) than large 20/65(30.8%); in farms practicing colostrum feeding between 6-12 hrs 23/71(32.4%) that those practicing in less than 6hrs 8/37(29.6%);in the farm practicing bedding11/31(35.5%) than those not practicing bedding20/67(29.9%). However, the risk factors were not statistically significantly associated (p>0.05) with the occurrence of Salmonella. Amongst the antibiotics that were tested, majority of Salmonella isolates were found to be highly susceptible to kanamycin, chloramphenicol, Spectinomycin, and tetracycline at with percentage of 100%, 90.3%, 80.6%, and 87.1%, respectively. Meanwhile all (100%) the isolates showed resistance to ampicillin, cefoxitin, and erythromycin. In conclusion, Salmonella could be considered as a potential *causative agent of diarrhea in calves. Therefore, satisfactory and essential attention should be given to management of calf by ensuring that the environment where calving takes place is disinfected properly from bacteria from previous calving, colostrum’s taken by calf in the first few hours of life and lack of proper ventilation of the pen should be prevented as much possible