title: Discrimination of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex species by Fourier transform infrared spectroscopy.
abstract: The main goal of this work was to assess the ability of Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) to discriminate between the species of the Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) complex, i.e. A. baumannii, A. nosocomialis, A. pittii, A. calcoaceticus, genomic species "Between 1 and 3" and genomic species "Close to 13TU". A total of 122 clinical isolates of the Acb complex previously identified by rpoB sequencing were studied. FTIR-ATR spectra was analysed by partial least squares discriminant analysis (PLSDA) and the model scores were presented in a dendrogram form. This spectroscopic technique proved to be effective in the discrimination of the Acb complex species, with sensitivities from 90 to 100%. Moreover, a flowchart aiming to help with species identification was developed and tested with 100% correct predictions for A. baumannii, A. nosocomialis and A. pittii test isolates. This rapid, low cost and environmentally friendly technique proved to be a reliable alternative for the identification of these closely related Acinetobacter species that share many clinical and epidemiological characteristics and are often difficult to distinguish. Its validation towards application on a routine basis could revolutionise high-throughput bacterial identification.
authors.affiliation: REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
authors.forename: C
authors.initials: C
authors.lastname: Sousa
authors.forename: L
authors.initials: L
authors.lastname: Silva
authors.forename: F
authors.initials: F
authors.lastname: Grosso
authors.forename: A
authors.initials: A
authors.lastname: Nemec
authors.forename: J
authors.initials: J
authors.lastname: Lopes
authors.forename: L
authors.initials: L
authors.lastname: Peixe
mesh_terms: D000151:Acinetobacter Infections / Q000175:diagnosis* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000737:chemistry* / Q000302:isolation & purification; D016954:Acinetobacter calcoaceticus / Q000737:chemistry* / Q000302:isolation & purification; D003937:Diagnosis, Differential; D016002:Discriminant Analysis; D006801:Humans; D016018:Least-Squares Analysis; D012680:Sensitivity and Specificity; D017550:Spectroscopy, Fourier Transform Infrared