SAG and bacterial infectious disease with sepsis: To evaluate if the SAB-0485 and SAB-0495 strains exhibited increased persistence in vivo, we utilized an experimental model of bacteremia in transgenic mice that express the human MHC-II molecule human leukocyte antigen (HLA)-DR4 (herein referred to as DR4-B6 mice) and are sensitive to SAg function (13, 18).