Investigating Antibiotic Resistance Patterns in Bacteria Causing Urinary Tract Infections among Patients Referred to Two Medical Diagnosis and Treatment Centers in Yazd, Iran

Urinary tract infections (UTIs) are prevalent infectious conditions affecting individuals in their youth and middle age. The increased use of broad-spectrum antibiotics and the growing resistance to these drugs emphasize the necessity of understanding bacterial resistance patterns in the context of treatment. This study aimed to identify the resistance patterns of bacteria causing UTIs in patients attending two medical diagnostic and treatment centers in Yazd, Iran. Conducted for one year (2018), this descriptive-cross-sectional study involved analyzing 3563 samples of UTI agents collected from the microbiology department of the Central Diagnostic Laboratory and Shahid Sadoughi Hospital in Yazd. Identification of isolated bacteria utilized phenotypic methods, and antibiotic resistance assessments were performed using the disk diffusion method. Among 3563 positive isolates, 80.4% originated from outpatients, while 19.6% were from inpatients. The most prevalent bacteria causing UTIs in both centers were Escherichia coli (57.8%), Klebsiella pneumoniae (9.7%), Staphylococcus aureus (9.1%), Streptococcus agalactiae (7%), and Acinetobacter (0.2%). Escherichia coli isolates exhibited the highest antibiotic resistance, particularly against amoxicillin-clavulanate (62.9%) and nalidixic acid (61.9%). In hospitalized patients, resistance to ampicillin (86%) and cotrimoxazole (72%) was notable, with over half of these isolates displaying ESBL positivity. Given the varying distribution of antibiotic resistance among UTI-causing isolates in both inpatient and outpatient settings, understanding antibiotic resistance patterns in diagnostic-treatment centers across diverse geographical areas is imperative.