the mechanism of resistance in ampc-producing escherichia coli isolated from urinary tract infections

Background and aim: ampc β-lactamases are capable of hydrolyzing all β-lactams except cefepime and carbapenems. the detection of ampc-producing escherichia coli has a high priority in infection management. this research is aimed to investigate the resistant ampc- generating e. coli isolates and identify their genetic variety. methods: in this study, 230 e. coli isolates from patients having urinary tract infection symptoms were investigated in 2017-2018 to assess their susceptibility toward antimicrobial agents. ampc genes were evaluated by pcr and molecular typing using the 10-loci mlva method. mlva images were examined by bionumerics 6.6 software through the use of the upgma algorithms. results: the highest frequencies of susceptibility among e. coli isolates were to meropenem 96.08%, piperacillin-tazobactam 90.43%, followed by gentamicin 66.54%, ceftazidime 50%, ciprofloxacin 48.26%, ceftriaxone 41.74%. all e. coli isolates were resistant to amoxicillin-clavulanate. thirty-eight ampc-generating e. coli isolates were detected. the most abundant determinant was cit and ebc, fox, and dha had the next ranks, respectively. six major clusters and a singleton were identified by mlva. conclusion: ampc-generation ability is an effective feature in the resistance of e. coli isolates and its investigation is of crucial significance in infection management. the major mechanisms of ampc beta-lactamase vary depending on time and geographical location.