A Retrospective Cross-sectional Study on Prevalence and Susceptibility Pattern of Bacterial Pathogens Causing Urinary Tract Infections at a Teaching Hospital in Tehran, Iran

Background: Urinary tract infection (UTI) is the most prevalent infection among the community and hospitalized patients. Objectives: This study aimed to investigate the current antimicrobial susceptibility patterns among UTI agents in Tehran, Iran. Methods: This retrospective study analyzed 9836 urine samples collected from hospitalized patients within 2019 - 2020. The antibiotic susceptibility for commonly-used antibiotics was tested according to Clinical and Laboratory Standards Institute guidelines. Results: Based on the findings, Escherichia coli was the most prevalent etiological agent of UTIs (72.3%), followed by Klebsiella spp. (13.4%), Pseudomonas aeruginosa (4.8%), Acinetobacter spp. (2.8%), and other species (6.7%). Of isolated microorganisms, 943 cases (97%) belonged to gram-negative bacilli; however, 32 cases (3.05 %) were gram-positive cocci. The susceptibility rates of E. coli to amikacin, nitrofurantoin, gentamicin, imipenem, andcefoperazone were 88.4%, 87.5%, 68.3%, 65.9%, and62.6%, respectively. The sensitivity rates of Klebsiella spp. isolates for amikacin, nitrofurantoin, and imipenem were 87.6%, 71.5%, and 68.9%, respectively. Conclusions: The results of the present study characterized the misuse of antibiotics in Iran. Iranian surveillance studies will assist clinicians in choosing the most appropriate empirical treatment and preventing infections caused by resistant organisms.