Phenotypic and Genotypic Assessment of ESBL Production in Klebsiella pneumoniae Isolates from Kermanshah Medical Centers (Iran)

The acquisition of extended spectrum β-Lactamases (ESBL) has made Klebsiella pneumoniae resistant to various types of antibiotics. The aim of this research was to determine the antibiotic resistance pattern and the frequency of TEM, SHV, CTX-M, and PER genes in K. pneumonia strains isolated from Kermanshah medical centers.
In this analytical cross-sectional study, a total of 165 different samples of patients, were collected from three hospitals (Imam Reza, Imam Khomaini, and Taleghani) and a medical diagnostic laboratory (Reference laboratory) in Kermanshah city during 2014-2015. Among them, 100 isolates of K. pneumoniae were confirmed using API-20E kit. Antibiotic susceptibility test was performed by disk diffusion method and phenotypic screening test for ESBL production, was performed by combination disc. After extraction of bacterial genome, CTX-M genes (CTX-M-1 and CTX-M-9 groups), TEM, PER, and SHV were examined by PCR. Then, a number of PCR products were sequenced and analyzed using BLAST software.
Forty percent of the isolates were ESBL-producing and were 100% resistant to third generation of cephalosporins. The isolates of ICU and burn ward patients had a high prevalence of ESBL. The frequency of TEM, CTX-M-1, CTX-M, and SHV genes, were 28%, 32%, 35%, and 83%, respectively, but PER and CTX-M-9 group genes, were not found among the isolates.
The results of this study indicated that the dissemination of ESBL-producing K. pneumoniae isolates, has increased in the isolates from inpatients and outpatients in Kermanshah. Therefore, it can be concluded that multidrug resistant isolates have increased, especially in wards, where patients are hospitalized for a long time. Therefore, identification of ESBL-producing K. pneumoniae strains in medical diagnostic laboratories, seems necessary.