Characterization of Klebsiella pneumoniae Strains Isolated from Urinary Tract Infection: Detection of ESBL Characteristics, Antibiotic Susceptibility and RAPD Genotyping

Abstract

In this study, a hundred Klebsiella pneumoniae strains isolated from urinary tract infections were evaluated in terms of genotyping, susceptibility to certain antibiotics and detection of extended spectrum of beta lactamase (ESBL) production. The random amplified polymorphic DNA (RAPD-PCR) method was used to identify the genetic differentiation of K. pneumoniae isolates. A total of 26 different DNA bands ranging between 334 bp and 28033 bp were detected among the strains. It was found that 100 K. pneumoniae strains revealed 11 different RAPD profiles. Antibiotic susceptibility tests were conducted using a disc diffusion method against 16 antibiotics. Fifty-five different resistance profiles were determined among the strains. ESBL-productions of the strains were determined by the double disc synergy test (DDST) and ESBL E-test methods. ESBL production rates among the strains were found to be 55% by E-test method and 45% by DDST method. While ESBL-producing K. pneumoniae strains showed the greatest resistance to penicillin G (100%), followed by piperacillin (92.7%) and erythromycin (85.4%),the resistance rates of non ESBLproducing strains to those antibiotics were determined as 97.8%, 88.8% and 88.8%, respectively. Both groups of strains showed the highest sensitivity to meropenem. Based on the results obtained from the study, it was concluded that the detection of ESBL-producing strains by the E-test method was more sensitive than by the DDST method. Phenotypic and genotypic identification methods should be used together to detect ESBL presence. The RAPD-PCR method alone will not be adequate in the genotyping of the strains and alternative DNA-based methods should be used.