摘要Objective:To detect extended spectrumβ-lactamase (ESBL) and determine its prevalence in various clinical samples collected from Dehradun City Hospital. Methods:The samples were first cultured in MacConkey’s agar plates by streak plate method, then identified by Gram staining and biochemical tests. The isolated bacterial strains were then tested for antibiotic susceptibility by Kirby-Bauer method. TheESBL detection is then carried out by double disc diffusion method. Results: Off the 56 samples cultured, 21 strains were identified which were sixEscherichia coli(E. coli), sixKlebsiella, fourProteus, fourPseudomonas aeruginosa (P. aeruginosa) and only oneAcinetobacter. Eight out of 21 (38.1%) strains including three ofE. coli, three ofKlebsiella and two ofP. aeruginosa, were found to be resistance to all five antibiotics (piperacillin, amikacin, ampicillin, gentamicin, and ciprofloxacin). Initial screening using four antibiotics (cefotaxime, ceftazidime, aztreonam and ceftriaxone) and the final confirmatory test using ceftazidime/clavulanic acid and ceftazidime alone showed that 19.05% of all strains isolated wereESBL producers. Individually, 16.67%E. coli, 16.67%Klebsiella pneumoniae, 25%P. aeruginosa and 100%Acinetobacter were found to beESBL producers. Conclusions:Antibiotic resistance byESBL has become a major risk factor worldwide, therefore routine checkup and accordingly prescription are suggested.