Detection of CP5 and CP8 immune responses in mice challenged with S. aureus isolates.

CP8 antibody titers in mice challenged with CP8 S. aureus isolates. A panel of seven different CP8 isolates representing different combinatins of in vitro and in vivo CP8 expression were used to challenge mice; five CC12 isolates (PFESA1194 (in vitro +, in vivo +), PFESA1305 (–, +), PFESA1405 (–, +), PFESA2455 (–, +), PFESA1502 (–,–)) and two CC188 isolates (PFESA2089 (+, not tested in vivo), PFESA2058 (–, +)). CD1 mice (7–9 weeks of age, 10 per group) were administered three IP injections of ~ 2x106 CFU/animal in 0.5 mL at 0, 4 and 12 weeks and bled at week 27. CP8 antibody responses were measured using a CP8 specific cLIA assay. CP8 antibody responses were detected in mice infected with all isolates except the CC12-t160 isolate (PFESA1502) that didn’t express capsule in the IFA murine model.