Structural and Topological Differences between a Glycopeptide-Intermediate Clinical Strain and Glycopeptide-Susceptible Strains of Staphylococcus aureus Revealed by Atomic Force Microscopy

Novel cell surface topography was revealed on cocci from a glycopeptide-intermediate Staphylococcus aureus (GISA) clinical strain by using atomic force microscopy. The GISA isolate and its revertant had two parallel circumferential surface rings. One equatorial surface ring was observed in control strains. In vancomycin-susceptible strains, additional rings were formed in the presence of vancomycin. Ring depth measurements also revealed striking differences between the GISA strain and susceptible strains grown with or without vancomycin.