Discrimination of the Acinetobacter calcoaceticusAcinetobacter baumannii complex species by Fourier transform infrared spectroscopy

  • C. Sousa
  • L. Silva
  • F. Grosso
  • A. Nemec
  • J. Lopes
  • L. Peixe


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 calcoaceticusAcinetobacter 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.


Attenuate Total Reflectance Partial Little Square Discriminant Analysis Acinetobacter Baumannii Multivariate Data Analysis Test Isolate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Liliana Silva was supported by a doctoral grant from Fundação para a Ciência e a Tecnologia (SFRH/BD/88028/2012) and Clara Sousa was supported by a post-doctoral grant from Fundação para a Ciência e a Tecnologia (SFRH/BPD/70548/2010). Alexandr Nemec was supported by grant 13-26693S from the Czech Science Foundation.

We thank Lenie Dijkshoorn (Leiden) for the kind provision of several strains used in this study.

Conflict of interest

The authors declare that they have no conflict of interest.


  1. 1.
    Dijkshoorn L, Nemec A, Seifert H (2007) An increasing threat in hospitals: multidrug-resistant Acinetobacter baumannii. Nat Rev Microbiol 5(12):939–951PubMedCrossRefGoogle Scholar
  2. 2.
    Nemec A, Krizova L, Maixnerova M, van der Reijden TJ, Deschaght P, Passet V, Vaneechoutte M, Brisse S, Dijkshoorn L (2011) Genotypic and phenotypic characterization of the Acinetobacter calcoaceticusAcinetobacter baumannii complex with the proposal of Acinetobacter pittii sp. nov. (formerly Acinetobacter genomic species 3) and Acinetobacter nosocomialis sp. nov. (formerly Acinetobacter genomic species 13TU). Res Microbiol 162(4):393–404PubMedCrossRefGoogle Scholar
  3. 3.
    Grosso F, Quinteira S, Peixe L (2011) Understanding the dynamics of imipenem-resistant Acinetobacter baumannii lineages within Portugal. Clin Microbiol Infect 17(8):1275–1279PubMedCrossRefGoogle Scholar
  4. 4.
    Lai CC, Hsu HL, Tan CK, Tsai HY, Cheng A, Liu CY, Huang YT, Liao CH, Sheng WH, Hsueh PR (2012) Recurrent bacteremia caused by the Acinetobacter calcoaceticusAcinetobacter baumannii complex. J Clin Microbiol 50(9):2982–2986PubMedCentralPubMedCrossRefGoogle Scholar
  5. 5.
    Wisplinghoff H, Paulus T, Lugenheim M, Stefanik D, Higgins PG, Edmond MB, Wenzel RP, Seifert H (2012) Nosocomial bloodstream infections due to Acinetobacter baumannii, Acinetobacter pittii and Acinetobacter nosocomialis in the United States. J Infect 64(3):282–290PubMedCrossRefGoogle Scholar
  6. 6.
    Turton JF, Woodford N, Glover J, Yarde S, Kaufmann ME, Pitt TL (2006) Identification of Acinetobacter baumannii by detection of the bla OXA-51-like carbapenemase gene intrinsic to this species. J Clin Microbiol 44(8):2974–2976PubMedCentralPubMedCrossRefGoogle Scholar
  7. 7.
    Gundi VA, Dijkshoorn L, Burignat S, Raoult D, La Scola B (2009) Validation of partial rpoB gene sequence analysis for the identification of clinically important and emerging Acinetobacter species. Microbiology 155:2333–2341PubMedCrossRefGoogle Scholar
  8. 8.
    Šedo O, Nemec A, Křížová L, Kačalová M, Zdráhal Z (2013) Improvement of MALDI-TOF MS profiling for the differentiation of species within the Acinetobacter calcoaceticusAcinetobacter baumannii complex. Syst Appl Microbiol 36(8):572–578PubMedCrossRefGoogle Scholar
  9. 9.
    Preisner O, Guiomar R, Machado J, Menezes JC, Lopes JA (2010) Application of Fourier transform infrared spectroscopy and chemometrics for differentiation of Salmonella enterica serovar Enteritidis phage types. Appl Environ Microbiol 76(11):3538–3544PubMedCentralPubMedCrossRefGoogle Scholar
  10. 10.
    Sousa C, Grosso F, Meirinhos-Soares L, Peixe L, Lopes J (2012) Identification of carbapenem-resistant Acinetobacter baumannii clones using infrared spectroscopy. J Biophotonics. doi: 10.1002/jbio.201200075 PubMedGoogle Scholar
  11. 11.
    Naumann D, Helm D, Labischinski H (1991) Microbiological characterizations by FT-IR spectroscopy. Nature 351:81–82PubMedCrossRefGoogle Scholar
  12. 12.
    Maquelin K, Kirschner C, Choo-Smith LP, van den Braak N, Endtz HP, Naumann D, Puppels GJ (2002) Identification of medically relevant microorganisms by vibrational spectroscopy. J Microbiol Methods 51:255–271PubMedCrossRefGoogle Scholar
  13. 13.
    Krizova L, Bonnin RA, Nordmann P, Nemec A, Poirel L (2012) Characterization of a multidrug-resistant Acinetobacter baumannii strain carrying the bla NDM-1 and bla OXA-23 carbapenemase genes from the Czech Republic. J Antimicrob Chemother 67(6):1550–1552PubMedCrossRefGoogle Scholar
  14. 14.
    Nemec A, Janda L, Melter O, Dijkshoorn L (1999) Genotypic and phenotypic similarity of multiresistant Acinetobacter baumannii isolates in the Czech Republic. J Med Microbiol 48(3):287–296PubMedCrossRefGoogle Scholar
  15. 15.
    Nemec A, Dolzani L, Brisse S, van den Broek P, Dijkshoorn L (2004) Diversity of aminoglycoside-resistance genes and their association with class 1 integrons among strains of pan-European Acinetobacter baumannii clones. J Med Microbiol 53:1233–1240PubMedCrossRefGoogle Scholar
  16. 16.
    Tjernberg I, Ursing J (1989) Clinical strains of Acinetobacter classified by DNA–DNA hybridization. APMIS 97(7):595–605PubMedCrossRefGoogle Scholar
  17. 17.
    Gerner-Smidt P, Tjernberg I (1993) Acinetobacter in Denmark: II. Molecular studies of the Acinetobacter calcoaceticusAcinetobacter baumannii complex. APMIS 101(11):826–832PubMedCrossRefGoogle Scholar
  18. 18.
    Næs T, Isaksson T, Fearn T, Davis T (2002) A user-friendly guide to multivariate calibration and classification. NIR Publications, Chichester, UKGoogle Scholar
  19. 19.
    Savitzky A, Golay MJE (1964) Smoothing and differentiation of data by simplified least squares procedures. Anal Chem 36(8):1627–1639CrossRefGoogle Scholar
  20. 20.
    Barker M, Rayens W (2003) Partial least squares for discrimination. J Chemom 17(3):166–173CrossRefGoogle Scholar
  21. 21.
    Winder CL, Carr E, Goodacre R, Seviour R (2004) The rapid identification of Acinetobacter species using Fourier transform infrared spectroscopy. J Appl Microbiol 96(2):328–339PubMedCrossRefGoogle Scholar
  22. 22.
    Bosch A, Miñán A, Vescina C, Degrossi J, Gatti B, Montanaro P, Messina M, Franco M, Vay C, Schmitt J, Naumann D, Yantorno O (2008) Fourier transform infrared spectroscopy for rapid identification of nonfermenting gram-negative bacteria isolated from sputum samples from cystic fibrosis patients. J Clin Microbiol 46(8):2535–2546PubMedCentralPubMedCrossRefGoogle Scholar
  23. 23.
    Vaz M, Meirinhos-Soares L, Sousa CC, Ramirez M, Melo-Cristino J, Lopes JA (2013) Serotype discrimination of encapsulated Streptococcus pneumoniae strains by Fourier-transform infrared spectroscopy and chemometrics. J Microbiol Methods 93:102–107PubMedCrossRefGoogle Scholar
  24. 24.
    Sahl JW, Gillece JD, Schupp JM, Waddell VG, Driebe EM, Engelthaler DM, Keim P (2013) Evolution of a pathogen: a comparative genomics analysis identifies a genetic pathway to pathogenesis in Acinetobacter. PLoS One 8(1):e54287PubMedCentralPubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • C. Sousa
    • 1
  • L. Silva
    • 1
  • F. Grosso
    • 1
  • A. Nemec
    • 2
  • J. Lopes
    • 3
  • L. Peixe
    • 1
  1. 1.REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de FarmáciaUniversidade do PortoPortoPortugal
  2. 2.Laboratory of Bacterial GeneticsNational Institute of Public HealthPragueCzech Republic
  3. 3.REQUIMTE, Laboratório de Química Aplicada, Departamento de Ciências Químicas, Faculdade de FarmáciaUniversidade do PortoPortoPortugal

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