Identification and analysis of Staphylococcus aureus components expressed by a model system of growth in serum

A model system mimicking Staphylococcus aureus bacteremia was developed by growth in serum under microaerobic conditions. Eight genes induced by growt h in serum were identified, including an antimicrobial peptide biosynthesis locus, amino acid biosynthetic loci, and genes encoding putative surface p roteins. Nine independent insertions were found in the major lysine biosynt hesis operon, which encodes eight genes, is repressed by lysine in vitro, a nd is expressed in vivo.