Background and purpose: Urinary tract infection (UTI) is the most common bacterial infection in humans after respiratory infections and today, the incorrect use of antibiotics to treat UTI has caused the spread of antibiotic resistance and multidrug resistance (MDR) among uropathogens. Therefore, the aim of this study was to determine of antibiotic resistance pattern of bacterial etiological agents causing urinary tract infections in patients referred to Ganjovian Hospital in Dezful in the hope of helping in better and faster treatment of urinary tract infection.Materials and methods: In this cross-sectional descriptive study (medical thesis with ethical code IR.DUMS.REC.۱۴۰۰.۰۳۲) ۲۶۳ positive urine culture samples for bacteriological agents were examined. Bacterial identity was determined based on bacterial characteristics and standard biochemical tests. After identification, antibiotic susceptibility testing (AST) of all isolates was carried out, according to CLSI ۲۰۲۱ (clinical and laboratory standards institute) instructions. Afterwards extended-spectrum beta-lactamases (ESBLs), carbapenemase, and metallo- -lactamase were identified by phenotyping methods. The data were analyzed using WHONET ۲۰۲۰ and IBM SPSS V.۲۱ software for interpretation of AST results and statistical analysis.Results: The most frequent isolates were Escherichia coli (۴۸.۷%), Klebsiella (۲۴.۳%),Enterococcus (۹.۹%), and Pseudomonas aeruginosa (۶.۵%). E. coli and Klebsiella showed high resistance to cefotaxime, ceftriaxone, nalidixic acid, and trimethoprim/sulfamethoxazole (higher than ۶۰%).
Antibiotic resistance pattern of Enterococcus to ciprofloxacin was ۸۸.۵%, penicillin ۷۲%, tetracycline ۶۹.۲`%, amikacin ۶۲.۵%, and vancomycin ۵۲%. More than ۹۳% and ۸۰% of P. aeruginosa isolates were resistant to nitrofurantoin and nalidixic acid, respectively. The overall prevalence of ESBLs and carbapenemase producing bacteria was ۳۷.۶% and ۲۲.۶%, respectively. Besides, ۶۶.۶% isolates of carbapenamase producing bacteria were phenotypically positive for metallo- -lactamase production based on mCIM with eCIM method.Conclusion: Considering that E. coli and Klebsiella cause ۷۰% of urinary infections, and these bacteria have high resistance to cefotaxime, ceftriaxone, nalidixic acid, and trimethoprim/sulfamethoxazole, so experimental treatment with these antibiotics in patients with UTIs is not recommended. On the other hand, due to the presence and increasingnumber of ESBL and carbapenemaze producing bacteria, it is recommended to perform tests for detection of these enzymes, in order to prevent treatment failures.