Characterization of AmpC, CTX-M and MBLs types of B-lactamases in clinical isolates of Klebsiella pneumoniae and Escherichia coli producing Extended Spectrum B-lactamases in Kerman, Iran

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