Genome sequencing of Staphylococcus aureus isolates with different profiles of resistance to vancomycin.. Staphylococcus aureus

Low level resistance to vancomycin in Staphylococcus aureus (VISA) is a clinical hindrance because patients infected with such strains may fail antimicrobial therapy. Phenotypically, VISA strains present a thickening of the cell wall which may be the result of different sets of point mutations on different bacterial genes, usually accumulated during vancomycin therapy, leading to resistance. The high plasticity of bacterial genomes within a species makes it hard to determine which mutations are correlated to the resistance phenotype. We thus sought out to sequence several isolates presenting profiles of susceptibility (VSSA), heterogeneous resistance (hVISA) and homogeneous resistance (VISA) which were either clinically isolated with these phenotypes or induced to these phenotypes by serial passage in vitro.