Classification of Foodborne Pathogens by Fourier Transform Infrared Spectroscopy and Pattern Recognition Techniques

Fourier transform infrared (FT‐IR) spectroscopy was used to classify various foodborne pathogens (Bacillus cereus, Salmonella enterica, Escherichia coli and Listeria spp.) at the genus and strain level by pattern recognition techniques. Spectra were obtained on bacterial suspensions in 0.9% NaCl on Anodisc (aluminum oxide) filters (105–106 cfu/mm2) (Whatman Inc., Clifton, NJ). Species and strain‐specific FT‐IR vibrational combination bands were present at wave numbers between 1700 and 700 cm−1. Clear segregations between different genera, species and strains of bacteria were observed by principal component analysis. Results of soft independent modeling of class analogy demonstrated that the tested foodborne bacterial strains could be correctly classified (>94%), confirming that FT‐IR can detect biochemical differences between bacterial cells. FT‐IR is a promising technique for the identification of foodborne pathogens and could provide rapid identification and classification of bacteria.