Analysis of Pathogenic Bacterial and Yeast Biofilms Using the Combination of Synchrotron ATR-FTIR Microspectroscopy and Chemometric Approaches

• Main Authors: Samuel Cheeseman, Z. L. Shaw, Jitraporn Vongsvivut, Russell J. Crawford, Madeleine F. Dupont, Kylie J. Boyce, Sheeana Gangadoo, Saffron J. Bryant, Gary Bryant, Daniel Cozzolino, James Chapman, Aaron Elbourne, Vi Khanh Truong
• Format: Article
• Language: English
• Published: MDPI AG 2021-06-01
• Series: Molecules
• Subjects: biofilms; synchrotron; infrared; chemometrics; ATR; spatial heterogeneity
• Online Access: https://www.mdpi.com/1420-3049/26/13/3890

Biofilms are assemblages of microbial cells, extracellular polymeric substances (EPS), and other components extracted from the environment in which they develop. Within biofilms, the spatial distribution of these components can vary. Here we present a fundamental characterization study to show differences between biofilms formed by Gram-positive methicillin-resistant <i>Staphylococcus aureus</i> (MRSA), Gram-negative <i>Pseudomonas aeruginosa</i>, and the yeast-type <i>Candida albicans</i> using synchrotron macro attenuated total reflectance-Fourier transform infrared (ATR-FTIR) microspectroscopy. We were able to characterise the pathogenic biofilms’ heterogeneous distribution, which is challenging to do using traditional techniques. Multivariate analyses revealed that the polysaccharides area (1200–950 cm⁻¹) accounted for the most significant variance between biofilm samples, and other spectral regions corresponding to amides, lipids, and polysaccharides all contributed to sample variation. In general, this study will advance our understanding of microbial biofilms and serve as a model for future research on how to use synchrotron source ATR-FTIR microspectroscopy to analyse their variations and spatial arrangements.