A total of 113 Acinetobacter spp isolates were identified by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Antimicrobial susceptibility testing was carried out, and minimum inhibitory concentrations (MICs) were determined by the dilution method on Mueller-Hinton agar for ¦Â-lactams, aminoglycosides, fluoroquinolones, and colistin. The characterization of ¦Â-lactamases was investigated by phenotypic tests for the detection of metallo-¦Â-lactamases and oxacillinases. Resistance genes were screened for by quantitative PCR and sequenced when positive.
Among the 113 isolates, 80 (70.8 % ) were found to be resistant to imipenem with MICs ranging from 64 to 512 ¦Ìg/ml. The blaOXA?23?like gene was detected in 50 % (40/80) of the isolates and the blaOXA?24?like gene was detected in 21.2 % (17/80) of the isolates. In addition, the metallo-¦Â-lactamase blaNDM-1?like was detected in five isolates (6.2 % ).
This study represents the first description of autochthonous Acinetobacter spp producing metallo-¦Â-lactamase blaNDM-1?like and oxacillinases blaOXA?23?like and blaOXA?24?like in western Algeria.