Isolation and Antimicrobial Susceptibility Test of Non-typhoidal Salmonella from Raw Bovine Milk and Assessments of Hygienic Practices in Gursum District, Eastern Hararghe, Ethiopia

Introduction: Non-typhoidal Salmonella (NTS) is a significant human and animal pathogen worldwide. Most human infections are foodborne, but direct or indirect contact with animals also contributes annually. Epidemiological data on Salmonella are crucial to establish effective control measures. Methods: A cross-sectional study was conducted from July 2022 to January 2023 in Gursum District, Eastern Hararghe Zone, Ethiopia, to isolate NTS from raw bovine milk and assess associated sanitary practices. A total of 480 samples were collected from bucket swabs, milk handlers’ hands, and milk. Following pre-enrichment in buffered peptone water, samples were transferred to selenite cysteine and Rappaport-Vassilidis broths before plating on xylose lysine deoxycholate agar. Biochemical and antimicrobial susceptibility tests were performed. Results: Among 56 Salmonella isolates recovered, 22(13.7%) were from milk, 20(12.5%) from bucket swabs, and 14(8.8%) from hand swabs. Abadir and Funyan Bira kebeles recorded the highest isolation rates (20%) from bucket swabs. There was no statistically significant variation in Salmonella isolation across kebeles. The majority (95%) of respondents were female, and 83% were illiterate. While 20% reported milking cows while ill, only 14% routinely washed udders before milking, though 85% cleaned their hands and 90% cleaned milking equipment. All isolates were resistant to at least two antibiotics, with resistance rates of 91.07% to tetracycline, 82.14% to ampicillin, and 73.21% to penicillin. However, all isolates were sensitive to chloramphenicol (100%), nalidixic acid (91.07%), and ciprofloxacin (91.07%). Conclusion: The highest Salmonella isolation rates were found in milk and milk-contact surfaces at markets, indicating unhygienic handling practices from production to market. The widespread antibiotic resistance among isolates highlights the challenge of treating Salmonellosis and underscores the need to limit the misuse of antibiotics.