Molecular monitoring of Carbapenem-resistant, risk Factors and mortality rates of multidrug-resistant clinical isolates of Acinetobacter baumannii isolates in ICU Patients of Tehran

Introduction and Objective: Infections caused by multidrug-resistant (MDR) and carbapenemase-producing Acinetobacter baumannii present significant challenges for healthcare systems. These infections lead to increased hospitalizations, longer lengths of stay, and higher mortality rates. The objective of this study was to evaluate the proportion of carbapenem-resistant A. baumannii isolates, examine antibiotic resistance patterns, and investigate the relationship between clinical risk factors and mortality.
Methods: This cross-sectional study analyzed 185 samples from ICU patients in Tehran hospitals between October and December 2024. Bacterial identification utilized biochemical and molecular methods, while antimicrobial susceptibility was examined using disc diffusion and microdilution techniques. Carbapenemase production was assessed with the carbapenem inactivation test, and binary logistic regression analyzed risk factors for mortality.
Results: Acinetobacter baumannii was isolated from 49 samples (30.26%); 51% of infections were isolated, and the remaining were associated with pathogens such as Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and fungi. The mean age of the patients was 57 years, and 67.3% of the cases had underlying diseases. The mortality rate of the study subjects was 65.3% and was significantly associated with the length of hospital stay and mechanical ventilation. Logistic regression showed that hospital length of stay and diabetes were the main predictors of mortality. The highest antibiotic resistance was related to cephalosporins and carbapenems (100%). Also, 20 isolates (40.81%) were carbapenemase producers, all of which were multidrug-resistant.
Conclusion: The study highlights the association between mortality and factors such as age, underlying diseases, and hospitalization duration, underscoring the urgent need for strategies to address carbapenem-resistant and multidrug-resistant A. baumannii infections.