Determining the Risk Factors for Nosocomial Multidrug-Resistant Acinetobacter Infections in Patients in Intensive Care Units and Genotyping of Isolates

Objective: This study aimed to identify the risk factors for hospital-acquired Acinetobacter baumannii infections in an intensive care unit (ICU), delineate the antibiotic resistance profiles of isolates, and elucidate the clonal relationships among strains through genotypic analysis. Materials and Methods: This prospective case-control study was conducted between April 2011 and March 2012 and included 213 patients. The antibiotic susceptibility of Acinetobacter strains was evaluated using the Kirby–Bauer disk diffusion method. The DiversiLab system was used to determine the clonal relationships among A. baumannii strains. Results: The key independent risk factors for hospital-acquired A. baumannii infections included age, mechanical ventilator use, tracheotomy, percutaneous endoscopic gastrostomy (PEG), carbapenem administration, and nonuse of cephalosporins. High multi-antibiotic resistance was observed in 94% of the isolates. Furthermore, a substantial clonal closeness with an 86% clustering rate was observed among the isolates, with the largest cluster (P5) comprising 24 isolates persisting for approximately 14 months in the hospital setting. Conclusions: The findings indicate the need for targeted preventive measures against specific risk factors for A. baumannii infections in ICUs. The genotypic analysis revealed significant clonal spread, necessitating enhanced infection control strategies.