Staphylococcus haemolyticus diversity within a cell population

Staphylococcus haemolyticus is one of the most important nosocomial human pathogens frequently isolated in bloodstream and medical devices related infections. This species is notorious for its multidrug resistance and genome plasticity. However, the mechanisms of evolution and adaptation of S. haemolyticus are still poorly explored. In this study we aimed to characterize the strategies of genetic and phenotypic diversity in S. haemolyticus. Overall, our results suggest that S. haemolyticus populations, when grown in non-restrictive conditions, are composed of subpopulations of genetic and phenotypic variants that might be affected in antibiotic and stress resistance, specific metabolic processes and virulence. The maintenance of subpopulations in different physiological states might be a strategy to adapt rapidly to a stress situation imposed by the host particularly in the hospital environment.