Deciphering the role of monosaccharides during phage infection of Staphylococcus aureus

As phages are extensively investigated as novel therapy tools but also as transfer agents for antibiotic resistance genes, thorough understanding of phage—host interactions becomes crucial. Prerequisite for phage infection is its adhesion to the host surface. Herein, we used atomic force microscopy-based single-particle force spectroscopy with phage-decorated tips to decipher the adhesion of phage 187 on living Staphylococcus aureus cells. We found that addition of free N -acetyl- D -glucosamine was able to decrease phage adhesion, suggesting that this monosaccharide plays major role in phage 187 infection of S. aureus . Moreover, phage 187 adhesion on monosaccharide-coated model surfaces combined with plaque forming unit counts suggested that a direct link can be established between the propensity to bind to a saccharide and the capability of the latter to inhibit phage infection. On a nanoscale level, single-particle force spectroscopy was successfully used to identify a major receptor required for phage 187 infection of S. aureus but also evidenced that this receptor was responsible for phage adhesion on host-cells. Our work demonstrates that single-particle force spectroscopy is a powerful platform to screen and predict the molecular target of phages on their host surfaces.