The Study of <i>Escherichia coli</i> as Antimicrobial‐Resistant Sentinel Microorganism Isolated in the Farms of Three Districts of Ankara by MALDI‐TOF MS and Genomic Analysis

One Health is a unified approach that aims to sustain and maintain the health of humans, animals and the ecosystem. The environment plays an important role in the spread of resistance genes, as it is an unlimited source of antimicrobial resistance genes. Escherichia coli can acquire and spread resistance genes from its environment. Extended-spectrum beta-lactamase (ESBL)-producing E. coli is a global concern because it can hydrolyse many beta-lactam antibiotics. In this study, the aim was to isolate E. coli from faeces and soil samples collected from cattle, sheep and poultry in three districts (Golbası, Haymana and Cubuk) where livestock (cattle, sheep and poultry) farming activities are intensively carried out. In addition, the antibiotic susceptibility of the isolated E. coli was to be determined using phenotypic and genotypic methods and the presence of ESBLs was to be determined using a double-disc synergy test. All 120 E. coli isolates were confirmed by the MALDI-TOF MS method. The resistance rates of all isolates were as follows: ampicillin, 12.5%; trimethoprim/sulfamethoxazole, 6.6%; cefazolin, 0.83%; ciprofloxacin, 2.5%; ceftazidime, 0.83%; cefotaxime, 1.6% and ceftriaxone, 1.6%. Cefazolin (99.1%) and trimethoprim/sulfamethoxazole (0.83%) were determined to have intermediate susceptibility. Only one E. coli strain was found to be ESBL positive via phenotypic methods, and whole-genome analysis was performed on this strain. As a result of whole-genome analysis, ESBL-related CTX-M-14 and TEM-1 genes were found in the plasmids. This is the first study on the determination of antibiotic susceptibility and the presence of ESBL in E. coli isolated from the soil and faeces samples of farms in these regions. More studies are needed to determine and understand antibiotic resistance and ESBL positivity in environmental samples. Therefore, the One Health approach should be emphasised.