Bacteremia due to clonally derived methicillin-resistant, gentamicin-susceptible isolates and methicillin-susceptible, gentamicin-resistant isolates of Staphylococcus aureus.

We report recurrent bacteremia due to mixed infection with two clonally derived isolates of Staphylococcus aureus in a patient with Sezary syndrome. The two isolates, one gentamicin resistant and methicillin susceptible and the other gentamicin susceptible and methicillin resistant, developed by the deletion of the mecA, ant(4')Ia, and aacA-aphD genes from a common gentamicin-resistant and methicillin-susceptible ancestor.