MAS1 and Sepsis: To better understand how regulatory mutations that affect biofilm formation also impact the pathogenesis of diverse clinical isolates of S. aureus in a murine sepsis model, we generated isogenic mutants of the USA200 strain UAMS-1 in sarA, agr, codY, fur, sigB, rot, and mgrA. This strain was chosen because we carried out the same study previously with the USA300 strain LAC, and while LAC and UAMS-1 are both clinical isolates, they are very different by comparison to each other as detailed above.