Antibiotic resistance and bacterial profiles in an Iranian hospital (2018-2021).

INTRODUCTION: Antimicrobial resistance (AMR) poses a significant global health challenge, complicating the treatment of bacterial infections. This study investigated the prevalence of AMR among clinical isolates in an Iranian hospital from 2018 to 2021. METHODOLOGY: This four-year retrospective study was conducted at Ganjavian Hospital in Dezful, Iran. A total of 4,522 clinical specimens were analyzed. Bacterial identification and antimicrobial susceptibility testing were performed using standard microbiological methods and the Kirby-Bauer disk diffusion method, and interpreted per the Clinical and Laboratory Standards Institute (CLSI) guidelines. Statistical analysis included descriptive statistics, Chisquare tests for trend, and 95% confidence intervals (CIs) for resistance proportions. RESULTS: A total of 4,282 bacterial isolates were recovered; of which 78% were Gram-negative, with Enterobacterales constituting the predominant group (51.4%). Among Escherichia coli isolates, 72.3% (95% CI: 69.9-74.6%) were non-susceptible to ceftriaxone. The prevalence of multidrug-resistant (MDR) Enterobacterales was 41.4% (95% CI: 39.2-43.6%), with significant annual variation observed during the study period (χ² = 5.48, p < 0.001). Acinetobacter spp. exhibited high resistance to third-generation cephalosporins (94.1%; 95% CI: 91.1-96.2%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) was 29.7% (95% CI: 25.6-34.1%), and 40.0% of Enterococcus spp. were vancomycin-resistant. CONCLUSIONS: The findings highlight the urgent need for enhanced infection-control and antimicrobial-stewardship programs. The high rates of resistance among common pathogens underscore the complexity of treating infections in critical care settings. This study emphasizes the necessity for surveillance and the development of targeted interventions to combat AMR, ensuring that effective treatment options remain available.