Associated resistance of Escherichia coli isolated from humans and animals to polymyxin and beta-lactam antibiotics

Escherichia coli isolates from various sources 2018 to 2019 were included in the study. Mcr-1 genes found two of 105 animal strains (2%) and seven 928 human (0.8%). All mcr-1-positive showed a low level resistance colistin (MIC ranged 4 8 µg/ml). Both isolated animals remained sensitive betalactam antibiotics did not contain beta-lactamase genes. Beta-lactamases absent only one humans. Four resistant cephalosporins with sensitivity carbapenems carried class A (blaCTX-M-15 or blaCTX-M-1) C (blaCMY-2) extended-spectrum beta-lactamases One strain meropenem contained four genes: blaNDM-1, blaCTX-M-15, blaTEM-1B, blaCMY-6. Only ciprofloxacin, rest high resistance, had amino acid substitutions DNA gyrase mutations leading overexpression mdfA gene. In terms aminoglycosides, varied widely up aminoglycoside-modifying enzyme humans tigecycline, but no conferring this antibiotic found. The data obtained substantiate need for extended studies on molecular epidemiology associated polymyxins beta-lactams.