Journal of Krishna Institute of Medical Sciences University (Oct 2019)
Prevalence of Extended Spectrum Beta Lactamase Genotypes in Klebsiella pneumoniae from Respiratory Tract Infections at Tertiary Care Hospital
Abstract
Background: Extended Spectrum Beta Lactamases (ESBLs) are rapidly evolving group of β-lactamase enzymes that are of particular concern to clinicians and epidemiologists. Most ESBLs have been evolved by genetic mutation from blaTEM and blaSHV genes, and are well described in Klebsiella pneumoniae. Aim and Objective: To investigate the ESBL genotypes in K. pneumoniae isolates from Respiratory Tract Infections (RTIs). Material and Methods: Clinical isolates of K. pneumoniae were obtained from RTI -sputum samples. Antimicrobial susceptibility was determined by Kirby- Bauer disc diffusion method. ESBL was detected phenotypically and multiplex Polymerase Chain Reaction (PCR) specific for blaTEM, blaSHV and blaCTX-M genes was performed to identify genotypes. Results: During the 19 months period, a total of 212 of K. pneumoniae were found from RTIs. Of these 212 isolates, 60 isolates (28.3%) were ESBL producers by phenotypic method. Of these 212 isolates, 96 were randomly selected for multiplex PCR for blaTEM, blaSHV and blaCTX-M genes. The findings of multiplex PCR showed that 24 isolates (25%) possessed blaTEM gene and only 4 isolates (4.1%) possessed each blaSHV and blaCTX-M gene alone. Isolates having both blaTEM+blaSHV genes were 20 (20.8%), and both blaTEM+blaCTX-M genes were 12 (12.5%); and isolate possessing all three blaTEM+blaSHV+blaCTX-M genes were 20 (20.8%). The overall prevalence of blaTEM, blaSHV and blaCTX-M genes in this study was 79.1%, 45.8% and 37.5% respectively. Imipenem was most effective antibiotic. Conclusion: Spread of ESBL producing K. pneumoniae is a major concern, as it causes limitations to optimal treatment. Multiplex PCR can be used as a rapid method to identify ESBL genotypes in K. pneumoniae. It will prove valuable for surveillance and establishing the treatment line against drug resistant organisms, thus saving precious time and resources. In our study blaTEM genotype was most prevalent.