Based on the impact of Aur and ScpA on multifactorial phenotypes associated with the pathogenesis of osteomyelitis and previous work demonstrating that eliminating the ability to produce Aur and ScpA was both necessary and sufficient for hypervirulence in LAC (10, 11), we first used our murine osteomyelitis model to assess the relative virulence of LAC and its protease, aur/scpA, sarA, protease/sarA, and aur/scpA/sarA mutants. This evidence concerns the gene LCT and osteomyelitis.