Identification of carbapenem-resistant Acinetobacter baumannii clones using infrared spectroscopy.

In this work we assessed the discriminatory ability of Fourier-transform Infrared Spectroscopy (FTIR) in 22 representative isolates from a collection of 318 carbapenem-hydrolyzing class D β -lactamases (CHDL)-producing Acinetobacter spp. (5 hospitals; 2001-2008) previously characterized by DNA-based typing methods. FTIR spectra were acquired with a Bruker spectrometer and analyzed with support of several chemometric tools. The results showed that FTIR spectroscopy was able to distinguish the main CHDL-producing Acinetobacter baumannii lineages causing infection in Portugal, the ST103 carrying blaOXA-58 , ST98 carrying blaOXA-24/40 and ST92 carrying blaOXA-23 . Moreover, this study revealed distinctive phenotypic features of A. baumannii lineages causing infections that might justify different epidemic potential. Spectroscopy may arise as a low cost and easily to perform alternative for typing A. baumannii isolates.