Left ventricular assist device-associated endocarditis involving multiple clones of Staphylococcus aureus with distinct antimicrobial susceptibility patterns.

The case of a patient with left ventricular assist device (LVAD)-associated endocarditis involving multiple clones of Staphylococcus aureus is presented. Different clones with distinct colony morphology were identified from blood cultures collected on the same day and showed diverse antimicrobial resistance patterns. In addition, a difference in antimicrobial susceptibility was observed even within an identical clone recovered 400 days apart due to the loss of SCCmec for methicillin and modification of the 23S rRNA target site for linezolid during a long-term treatment course.