NMR Metabolomics and DNA Sequencing of Escherichia coli and Staphylococcus aureus Cultures Treated with Hydrolyzable Tannins

Abstract

<p><i>Escherichia coli and Staphylococcus aureus</i> are globally among the most prominent bacterial strains associated with antibacterial resistance-caused deaths. Naturally occurring polyphenols, such as hydrolyzable tannins, have been shown to potently inhibit E. coli and S. aureus. The current study investigated the metabolome changes of <i>E. coli and S. aureus</i> cultures after treatments with different hydrolyzable tannins using an NMR metabolomics approach. Additionally, the effect of these tannin treatments influencing a more complex bacterial system was studied in a biomimetic setting with fecal samples inoculated into the growth medium. Metabolite concentration changes were observed in all three scenarios: <i>E. coli, S. aureus</i>, and fecal batch culture. The metabolome of <i>E. coli</i> was more altered by the tannin treatments than <i>S. aureus</i> when compared to control cultures. A dimeric hydrolyzable tannin, rugosin D, was found to be the most effective of the studied compounds in influencing bacterial metabolome changes and in inhibiting <i>E. coli and S. aureus</i> growth. It was also observed that the tannin structure should have both hydrophobic and hydrophilic regions to efficiently influence <i>E. coli and S. aureus</i> growth.<br></p>