Prevalence and Characterization of Extended Spectrum Beta-Lactamase Production in Clinical Isolates of Klebsiella pneumonia

Aim: This study was carried out to determine the presence of TEM and SHV genes in extended- spectrum β-lactamase (ESBL) producing Klebsiella pneumoniae. The study was also aimed to compare results of phenotypic confirmatory double disc diffusion test and genotypic methods. Materials and Methods: A total of 679 strains of Klebsiella pneumoniae were selected for the study from June 2012-December 2013. Kirby – Bauer disk diffusion method was performed to determine the antibiotic resistance pattern. Screened for ESBL and confirmed by phenotypic confirmatory disc diffusion test (PCDDT). 100 randomly selected isolates were investigated for the presence of TEM and SHV genes via Polymerase chain reaction (PCR) using two different sets of primers. Multiplex PCR was also performed for the same. Results: Phenotypic confirmatory test was able to detect ESBL production in 90.13% of Klebsiella pneumoniae isolates. Among the two ESBL genotypes, the most prevalent genotype was found to be TEM. Majority of ESBL producing isolates possess both ESBL genes. Conclusion: Multiplex PCR can be used as a rapid method to identify common genes (TEM and SHV) responsible for extended spectrum beta lactamase production in Klebsiella pneumoniae. It will prove valuable for surveillance and for determining the line of treatment against drug resistant organisms, thus saving precious time and resources. PCDDT results correlated with genotypic method in all the tested strains.