Background/objectives: The genus Acinetobacter demonstrates resistance to antibiotics and has been shown to spread in the hospital environment causing epidemic outbreaks among hospitalized patients. The objectives of the present study was to investigate the antibiotic resistance, biofilm formation, and clonality among Acinetobacter baumannii strains.
Materials and methods: The study involved 6 (I Outbreak) and 3 (II Outbreak) A. baumannii strains isolated from patients hospitalized in vascular surgery unit.
Results: All tested A. baumannii strains were extensively drug resistant (XDR) and all the isolates were carbapenem-resistant and among them, all carried the blaOXA-51 gene, the blaOXA-24 gene, as well as the blaOXA-23 gene. All of the investigated strains had the ability to form a biofilm, but all of them produced less biofilm than the reference strain. Multi-locus sequence typing (MLST) showed that all strains belonged to the ST2 clone. Pulsed-field gel electrophoresis (PFGE) divided the tested outbreak strains into two clones (A and B).
Conclusion: This study shows a nosocomial spread of XDR A. baumannii ST2 having the blaOXA-51 gene, the blaOXA-24 gene, as well as the blaOXA-23 gene, low biofilm formers, that was prevalent in the vascular surgery unit. To identify the current situation of vascular surgery departments targeted epidemiological investigation was needed. Effective implementation of infection control prevented the spread of the epidemic outbreaks.
Keywords: Acinetobacter baumannii; OXA-23; ST2 clone; epidemiological investigation; extensive drug resistance; hospital outbreak.