Antibiotic Susceptibility Profiling of E.coli Isolates

The identification and susceptibility profiles of these four and other E.coli isolates were reported previously (50 (link)); in brief, each isolate was tested against a panel of 10 antibiotics using the disk diffusion method. The antibiotics included were ampicillin (10 mg), piperacillin-tazobactam (30/6 mg), amoxicillin-clavulanic acid (20/10 mg), ceftazidime (10 mg), cefepime (30 mg), norfloxacin (10 mg), levofloxacin (5 mg), amikacin (30 mg), imipenem (10 mg), meropenem (10 mg), and chloramphenicol (30 mg) (Mast Group, Merseyside, UK) according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) protocol (52 ). Isolates were determined to be ESBL producing if they showed resistance to ceftazidime and cefepime.