RESUMO
Background and aims: Extended-spectrum beta-lactamase of CTX-M-type is considered as an important mechanism resistant to cephalosporin in the gram-negative patogene and is wildly growing. Enterobacteriaceae species are able to produce extended-spectrum beta-lactamases [ESBLs]. The aim of this study was to detect the prevalence of CTX-M genes in ESBLs producing enteric bacteria isolated in Shahrekord educational hospitals using Polymerase Chain Reaction method
Methods: In this analytical-descriptive study, antibacterial susceptibility patterns of 325 gram negative bacteria to Cefotaxim, Ceftazidim, Cefterixon and Azteronam tested using disk diffusion [Kirby-Buer] method. In addition, confirmatory tests for detecting ESBLs phenotypes were performed using Ceftazidim-clavulanic acid and Cefotaxim- clavulanic acid combination disks [MAST]. The presence of CTX-M gene was assessed using PCR
Results: Bacteria strains isolated in this study were Escherichia coli [59.4%], Klebsiella pneumoniae [30.4%], Enterobacter spp. [15.4%] and Proteus spp. [2.2%]. Confirmatory phenotypic test showed that 28% of the strains were ESBL positive. The prevalence of CTX-M gene in isolated Enterobacteriaceae was 50.5 %
Conclusion: High frequency of CTX-M gene in ESBL producing isolates indicates that this enzyme plays an important role in resistance to betalactam containing antibiotics