Evaluation of Resistance Determinants and Clonal Relationship of Extended-Spectrum Beta-Lactamase Positive Gram-Negative Bacterial Strains by PCR and Raman Spectrophotometry

Background: ESBLs are enzymes which are capable of hydrolysing penicillins, broad-spectrum cephalosporins and monobactams. They are generally derived from TEM and SHV-type enzymes. Materials and methods: We investigated the presence of TEM, SHV, CTX-M, OXA and IBC beta-lactamase genes by PCR in 300 E. coli, 130 Klebsiella spp., 100 P. aeruginosa ve 23 Enterobacter spp. isolated from various clinical specimens recovered from inpatient and outpatients. Additionally, epidemiological relationships were evaluated by Raman spectromicroscopy method. Results: According to the PCR results; blaTEM (49.3%) and blaCTX-M (52.6%) were found at high rates, but blaIBC was not detected in any isolates. When PCR test results were evaluated according to the origin of bacteria, the highest rates of blaTEM (69.3%) ve blaCTX-M (79.3%) were detected in E. coli isolates, while the lowest rate (1%) was found in P. aeruginosa. With raman spectromicroscopy, it was identified 9 cluster in E. coli, 6 cluster in K. pneumoniae and K. oxytoca, 11 cluster in P. aeruginosa and 3 cluster in E. Cloacae Conclusion: Although we obtained valuable results in the comparison of the raman spectrums in positive for resistance genes, there is a great necessity for standardisation of the studies prior to the usage of the test routinely.