Prevalence of Extended Spectrum Beta Lactamase Genotypes in Klebsiella pneumonia from Respiratory Tract Infections at Tertiary Care Hospital.

Background: Extended Spectrum Beta Lactamases(ESBLs) are rapidly evolving group of β-lactamaseenzymes that are of particular concern to clinicians andepidemiologists. Most ESBLs have been evolved bygenetic mutation from blaTEM and blaSHV genes, andare well described in Klebsiella pneumoniae. Aim andObjective: 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 KirbyBauer disc diffusion method. ESBL was detectedphenotypically and multiplex Polymerase ChainReaction (PCR) specific for blaTEM, blaSHV andblaCTX-M genes was performed to identify genotypes.Results: During the 19 months period, a total of 212 ofK. pneumoniae were found from RTIs. Of these 212isolates, 60 isolates (28.3%) were ESBL producers byphenotypic method. Of these 212 isolates, 96 wererandomly selected for multiplex PCR for blaTEM,blaSHV and blaCTX-M genes. The findings ofmultiplex 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 threeblaTEM+blaSHV+blaCTX-M genes were 20 (20.8%).The overall prevalence of blaTEM, blaSHV andblaCTX-M genes in this study was 79.1%, 45.8% and37.5% respectively. Imipenem was most effectiveantibiotic. Conclusion: Spread of ESBL producing K.pneumoniae is a major concern, as it causes limitationsto optimal treatment. Multiplex PCR can be used as arapid method to identify ESBL genotypes in K.pneumoniae. It will prove valuable for surveillance andestablishing the treatment line against drug resistantorganisms, thus saving precious time and resources. Inour study blaTEM genotype was most prevalent.