Molecular Epidemiology of AmpC-Producing Klebsiella Pneumoniae Isolated from Perioperative Patients in a Tertiary Hospital

Background: extended-spectrum cephalosporin-resistant organisms are the sources of ampc- type β-lactamase isolates. ampc-producing klebsiella pneumoniae isolates are a major challenge in clinics due to their high rate of antibiotic resistance. this study aimed to detect ampc β-lactamases in k. pneumoniae isolated from hospitalized patients with a surgical history.materials and methods: this cross-sectional study was performed on 120 urine catheter samples. after antibiotic susceptibility testing, plasmid-mediated ampc was detected by double-disc plus combined disc test (dcdt) and three-dimensional extract test (tdet). the genotypic detection of plasmid-mediated ampc was carried out using multiplex-polymerase chain reaction (pcr).results: of 120 samples, 60 (50%) instances of k. pneumoniae were isolated. the highest and lowest resistance rates were related to cefotaxime (ctx) (50%) and ciprofloxacin (cip) (23.3%), respectively. 18.3% (n: 11) k. pneumoniae showed an ampc phenotype in dcdt and tdet tests. ampc genotyping showed that the prevalence of cit, dha, ebc, and acc genotypes were 47.1%, 35.3%, 29.5%, and 23.6%, respectively. mox and fox genotypes were not identified in the isolates of interest.conclusion: ampc β-lactamase identification tests should be considered a routine microbiology workup for gram-negative microorganisms. multiplex-pcr can identify the plasmid ampc genotypes.