Resistance and Virulence Features in Carbapenem-resistant Acinetobacter baumannii Community Acquired and Nosocomial Isolates in Romania
We aimed to identify the virulence and antimicrobial resistance features in Carbapenem Resistant Acinetobacter baumannii (CRAB) strains isolated from hospital settings and compare them with those isolated in the same period of time from community acquired (CA) infections in Bucharest, south of Romania. A total number of 93 A. baumannii strains were isolated in majority from hospitalized patients and from CA infections. The resistance and virulence mechanisms of the strains were characterized by phenotypic and genotypic methods. The antibiotic resistance profiles in H and CA A. baumannii isolates revealed high percentages of carbapenem-resistance in both H and CA isolates. The ciprofloxacin resistance was found very closed in both types of isolates (84%/83.33%). CRAB H and CA isolates revealed the intrinsec carbapenemase OXA-51and the acquired carbapenemases OXA-23, OXA-24, IMP,and VIM-2. The blaOXA-23 gene was identified in different plasmid types (GR2-Aci1, GR6-pACICU2). rep135040, p3S18 and Aci6 in H A. baumannii isolates. The most frequently expressed virulence factor was lipase and DN-ase. OXA-51-like alleles corresponding to the two main sequence groups were identified as blaOXA66 (63.63% of the isolates) and respectively, blaOXA-69 (38.39%) and revealed the corresponding type of ompAand csuE sequence grouping. AphA6 (24%/16.6%), AphA1 (16%/16.6%) and aadB (9.3%/5.5%) genes were responsible for aminoglycosides resistance. Our survey revealed a high drug resistance in A. baumannii isolates. Different plasmid groups containing CRAB isolates may facilitate the blaOXA23 dissemination.