Antibiogram and characterization of resistance markers among Escherichia coli isolates from urinary tract infections

Abstract

Introduction: Urinary tract infection is the most frequently diagnosed kidney and urologic disease, and Escherichia coli is by far its most common etiological agent. Uropathogenic E. coli are responsible for approximately 90% of urinary tract infections seen in individuals with ordinary anatomy therefore, it is essential to review the antibiogram of uropathogenic E. coli periodically to help clinicians decide on the appropriate therapy. Methodology: We evaluated E. coli isolated from urinary tract infections at the National Salmonella and Escherichia Centre for antibiogram, plasmid transferability and stability of resistance markers.Results: In total, 90.9% of the isolates were found to be sensitive to nitrofurantoin while the highest proportion of the isolates was found to be resistant to nalidixic acid. Minimum inhibitory concentrations of all antimicrobials for different isolates were well within the limits specified by the Clinical and Laboratory Standards Institute. Resistance against tetracycline was not transferred either by conjugation and transformation. Streptomycin resistance was found to be lost in the maximum number of tested isolates showing loss at the 10th, 15th and 20th passages. Conclusion: Changing trends in antibiotic resistance necessitates the periodic generation of antibiogram data to help health authorities revise treatment strategies for urinary tract infections caused by E. coli. © 2013 Kumar et al.