characterization of ampc, ctx-m and mbls types of β-lactamases in clinical isolates of klebsiella pneumoniae and escherichia coli producing extended spectrum β-lactamases in kerman, iran

background: extended spectrum β-lactamases (esbls) and ampc β-lactamases enzyme are major sources of resistance to β-lactam antibiotics especially in enterobacteriaceae such as escherichia coli and klebsiella pneumoniae. increasing frequency of the co-existence of esbls with ampc-β-lactamases in bacteria is a serious threat for treating bacterial infections. conclusions: outbreak of isolates co-expressing ampc-β-lactamases and esbls can cause serious problems in the future, regarding the treatment of infections caused by these common enteric pathogens. results: the prevalence of esbls and ampc-β-lactamase producer isolates was 181 (43.8%) and 133 (37.2%), respectively. the prevalence of blactx-m among isolates was 61 (14.7%). materials and methods: resistance to different antibiotics was determined using the standard disk diffusion method. esbls, mbls and ampc-β-lactamases were detected by the combination double disk test (cddt) method and polymerase chain reaction (pcr) was used to determine blactx-m genes in the esbls and ampc positive isolates. objectives: the aim of this study was to determine the presence of ampc and ctx-m types of β-lactamases in clinical isolates of e. coli and k. pneumoniae producing esbls.