Antimicrobial Resistance of Commensal Escherichia coli Isolated from Food Animals in Qatar.

Objectives: This study aims at evaluating the phenotypic and genotypic antimicrobial resistance (AMR) patterns of 18 clinically relevant antibiotics in food animals in Qatar. Materials and Methods: Fecal samples from camels, cattle, and pigeons (300) were collected from different slaughterhouses and farms. Escherichia coli isolates were recovered on selective media, confirmed biochemically, and tested for antibiotic susceptibility using a disk diffusion assay. Any isolate that showed resistance to colistin was confirmed using the E-test and polymerase chain reaction for mcr genes. Results: Overall, a total of 88.7% ( n  = 266/300) recovery rate was achieved from all samples. Resistance to at least one antibiotic was recorded in 70.7% of pigeons, 37.2% of cattle, and only 20.8% of camel samples. Multidrug resistance (MDR) was highest in isolates from pigeons, 50% ( n  = 44). Moreover, trimethoprim/sulfamethoxazole (an antibiotic used to treat a variety of bacterial infections) resistance was present in 22.2% ( n  = 59) of all E. coli isolates. Only one E. coli isolate from a pigeon showed resistance to colistin ( mcr-1 gene encoded), a drug of last resort in human medicine against gram-negative bacterial infection. Conclusions: We previously reported high multidrug resistance of E. coli in chickens, with significant resistance to colistin. We observed a lower AMR profile in ruminants. The high resistance profile observed in pigeons (70.7%), including high multidrug resistance (50%), is alarming as these animals could rapidly disseminate resistant bacteria to various locations. Continuous monitoring of AMR in livestock in Qatar is necessary toward introducing an antimicrobial stewardship program and control of antibiotic usage in the veterinary sector.