High prevalence of heteroresistance in Staphylococcus aureus is caused by a multitude of mutations in core genes

Heteroresistance is a phenotype where, in a population of susceptible cells, small subpopulations of resistant and often unstable cells exist. This study shows that in the human pathogen Staphylococcus aureus, heteroresistance is widespread and caused by common point mutations in core genes. Examination of 40 isolates reveals that up to 2/3 of all isolates might be heteroresistant to a specific antibiotic, with the potential to cause treatment failure.