Identification of CTX-M type Extended Spectrum ?-Lactamase Genes in Escherischia coli and Klebsiella pneumoniae Isolates by PCR, PCR-RFLP, DNA Sequencing methods and determination of clonal relation between these strains by PFGE method

CTX-M type ESBL producer E.coli and K.pneumoniae strains have become an important cause of treatment failures both in nosocomial and community acquired infections with increasing prevelance ratios all over the world. In control of CTX-M type ESBL producer strains which became multi drug resistant because of failure of alternative treatment options, the most important option is effective surveillance in clonal level.The presence of CTX-M type ESBL producing E.coli and K.pneumoniae species has been shown by limited number of studies in our country. Although the presence of ESBL producing strains is known in our region, there is no data regarding the CTX-M type ESBL producing strains and their subtypes observed.Aim of this study was to investigate the prevelance of CTX-M type ESBL producing strains, types of enzymes and probable clonal relation between these strains isolated from clinical material belonging to both nosocomial and community acquired infections at the central laboratory of our hospital.At the end of the study; CTX-M type enzymes among ESBL producing E.coli isolates have been identified at a ratio of 87,31% (69/79) and 88,88% (24/27) between K.pneumoniae isolates with PCR method. Moreover, group specific PCR, PCR-RFLP and DNA Sequencing assays showed that 94.6% (88/94) of our strains are CTX-M-1 group/CTX-M-15 subtype enzyme producers and the other 5 (5.3%) are CTX-M-9 group/CTX-M-14 subtype enzyme producers. PFGE method which we used to identify clonal relations among our isolates demonstrated that there is no serious clonal dissemination between our strains.