Antibiogram of Escherichia coli Isolated from Dairy Cattle and in-Contact Humans in Selected Areas of Central Ethiopia

Tekalign Tadesse,1,* Haile Alemayehu,2 Girmay Medhin,2 Aberaw Akalu,3 Tadesse Eguale2,4,* 1Department of Veterinary Science, Mattu University, Mattu, Ethiopia; 2Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia; 3Food, Medicine and Healthcare Administration and Control, Addis Ababa, Ethiopia; 4The Ohio State University, Global One Health LLC, Addis Ababa, Ethiopia*These authors contributed equally to this workCorrespondence: Tekalign Tadesse, Department of Veterinary Science, Mattu University, P.O Box 318, Mattu, Ethiopia, Email tsquaregr@gmail.comBackground: Antimicrobial resistance (AMR) is a global threat to public and animal health. Escherichia coli is considered an indicator organism for monitoring AMR among gram-negative Enterobacteriaceae in humans and animals. The current study aims to assess the antibiogram profile of E. coli isolated from dairy cattle and in-contact humans in central Ethiopia and to identify risk factors associated with multidrug resistance (MDR).Methods: A cross-sectional study was conducted in which 58 farms were recruited from selected districts of central Ethiopia. E. coli was isolated using standard bacteriological techniques. A total of 200 representative isolates (140 from cattle and 60 from humans in contact) were randomly selected and tested for susceptibility to a panel of 13 antimicrobials using the Kirby-Bauer disc diffusion assay.Results: The highest rate of resistance was observed for sulfamethoxazole+trimethoprim (58.6%, 82/140) and amoxicillin+clavulanic acid (70.0%, 42/60) among E. coli isolates from cattle and hmans, respectively. In contrast, resistance rates in isolates from in contact humans with the cattle were 30%, 33.3%, and 66.7%, respectively. Resistance to tetracycline (p=0.02), streptomycin (p=0.03), and sulfamethoxazole+trimethoprim (p=0.007) was significantly high in E. coli isolated from cattle on commercial dairy farms than in those isolated from ca