Prevalence and antibiotic resistance pattern of Campylobacter species isolated from raw cow milk in Urmia, Iran

Campylobacter species are the most common bacterial cause of diarrhea in humans. The present study investigated the prevalence and antibiotic resistance of Campylobacter spp. isolated from raw milk in Urmia, Iran. Eighty raw cow milk samples were randomly collected from traditional dairy retailers in different regions of Urmia by sterile conditions in ۲۰۱۸. First, the samples were enriched in supplemented Preston broth, and then they were streaked onto supplemented Campylobacter agar and incubated at ۴۲ °C for ۴۸ h in microaerophilic conditions. Biochemical tests, such as hippurate hydrolysis and susceptibility or resistance to nalidixic acid, were performed to identify the species of isolates. Antibiotic sensitivity test on isolates was performed by the Kirby-Bauer disc diffusion method. Thirteen samples (۱۶.۲۵%) were contaminated with Campylobacter spp. The prevalence of Campylobacter jejuni (۱۳.۷۵%) was higher than Campylobacter coli isolates (۲.۵%). The Campylobacter isolates showed high resistance against tetracycline (۱۰۰%), co-trimoxazole (۸۴%), ampicillin, ceftriaxone, and chloramphenicol (۶۹.۲%) while exhibiting moderate resistance to ciprofloxacin and nitrofurantoin (۴۶.۲%) and low resistance to gentamicin (۳۰.۸%). Moreover, nine isolates (۶۹.۲%) showed multi-drug resistance (MDR). It can be concluded the prevalence of Campylobacter spp. and their MDR strains in distributed raw cow milk in Urmia is high. It is recommended to improve animal health and milk hygiene, prevent the overuse of antibiotics in dairy farms, and pasteurize milk.Keywords: Raw milk, Campylobacter species, Antibiotic resistance pattern, Urmia, Iran