Discrimination and classification of Enterococci by Fourier transform infrared (FT-IR) spectroscopy

FT-IR spectroscopy and multivariate analysis have been used to investigate four closely related species of an important bacteria genus: Enterococcus. Since some species belonging to this genus are highly pathogen, and some others present technological interest in food industry, their differentiation is an essential task. The aim of this work was to discriminate Enterococcus strains (9 E. faecalis, 12 E. faecium, 4 E. durans and I E. hirae) at the species and strain level, using FT-IR spectroscopy. Experiments were performed in two different laboratories with a good reproducibility, and were checked against a molecular biology technique, ribotyping. Discrimination at the species level was correct with both methods. Regarding the strain level, more than half the E. faecalis and E. faecium strains were differentiated by FT-IR spectroscopy, which confirms to be a rapid and promising method in microbiology. (C) 2003 Elsevier B.V. All rights reserved.