Prevalence and antimicrobial susceptibility pattern of ESBL producing isolates

Extended spectrum β-lactamases (ESBLs) are produced by Gram negative bacteria showing resistance to new generations of antimicrobial agents. This study was undertaken to characterize ESBL producing bacteria from 222 urinary isolates. Antimicrobial resistance was screened by disc diffusion test. The ESBL status was confirmed by double disc diffusion test (DDDT) and minimum inhibitory concentration (MIC) by agar dilution method by standard procedure. The study revealed the following distribution of ESBL producing isolates: Klebsiella spp (81.6%), Proteus spp (78.1%) E. coli (72.3%) and Pseudomonas spp (66.7%). All the isolates were sensitive to imipenem and nitrofurantoin followed by amikacin 92.9%. A relatively higher rate of resistance to gentamicin, co-trimoxazole, azithromycin and quinolones were also observed for ESBL producers. The study suggested routine detection of ESBL and avoidance of irrational use of third generation cephalosporins to reduce the emergence of multidrug resistance bacteria following an antibiotic policy.