Campylobacter is one of the major causes of gastroenteritis and is commonly transmitted through the consumption of raw milk or improperly pasteurized milk. A cross-sectional study was conducted from January 2019 to March 2020 in four study sites in the Oromia region of Ethiopia to isolate, identify, and estimate the prevalence of Campylobacter species in milk samples and to determine their antibiotic susceptibility pattern. A total of 384 cow milk samples were randomly chosen from 192 samples of raw milk from farmers and collectors and 192 samples of pasteurized milk from processors and retailers. Standard bacteriological techniques and PCR were used to isolate and identify Campylobacter spp. Of the total 384 milk samples, 35 (9.1%) were found to be positive for Campylobacter spp. The prevalence of Campylobacter spp. was highest in collector raw milk (13.5%), farmer raw milk (12.5%), and pasteurized milk (5.2%).The antibiotic susceptibility test was performed using the disc diffusion method. The most prevalent Campylobacter spp. isolated from milk samples was Campylobacter jejune (C. jejuni) (100%). The overall prevalence of Campylobacter in dairy value chains, including producer, collector, processor, and retailer, was 12.5%, 13.5%, 5.2%, and 5.2%, respectively. Cold storage, material type for making collection rooms, calibrating the pasteurizer machine, restricting milk handlers that are sick, means of transportation, and maintaining temperature during transportation had a statistically significant association. 100% and 8.6% of the Campylobacter isolates were sensitive to ciprofloxacin and chloramphenicol, respectively. However, all of the isolates were resistant to ampicillin, clindamycin, oxytetracycline, and trimethoprim. Moreover, 80% of the C. jejuni were resistant to tetracycline and streptomycin. 26% of the species developed ciprofloxacin degradation. The result of this study revealed the prevalence and risk factors of Campylobacter species in raw and pasteurized milk samples. Hence, there is a chance of acquiring infection via the consumption of raw or undercooked milk. Thus, the implementation of hygienic practices from the producer to the retailer's market, proper handling to avoid cross-contamination and proper pasteurization are very important in preventing Campylobacter infection.

Keywords: Foodborne, Campylobacter, thermophile, fluoroquinolone