Objective: Acinetobacter baumannii is an important nosocomial pathogen that can survive for months even in inanimate environments. In recent years, many virulence factors of A. baumannii have been described. This study was conducted to investigate various virulence factors of A. baumannii and to examine their clinical importance.

Methods: The study was carried out with A. baumannii isolates of various clinical samples and the ones in the bacteriology archive. Antibiotic susceptibility tests of bacteria were done by disk-diffusion method in accordance with EUCAST standards. Then, cvaC, iutA, csgA, cnf1 genes of these isolates were assessed with real time PCR.

Results: A total of 121 isolates were included in the study. Isolates were mostly obtained from endotracheal aspirates (n=54, 44.6%) and wound swabs (n=42, 34.7%). The most effective antibiotic was found to be colistin while colistin resistance was found in four isolates (3.3%). At least one virulence gene was detected in all isolates, while all virulence genes were detected together in one isolate. The iutA gene was found in at most 110 isolates (90.9%) and the cnf1 gene was found in at least four isolates (3.3%). The csgA and cvaC genes were also detected in 15 isolates (12.4%) and 81 (66.9%) isolates, respectively.

Conclusion: Although siderophore and bacteriocin genes were isolated in most of the isolates, genes responsible for colonization and direct cellular cytotoxicity were found to be less common.