FIG. 2.

Protective efficacies of pilus subunits in mice. The protective efficacies against TIGR4 challenge of either active vaccination with the indicated immunogens (active immunization) or passive transfer of the indicated antisera (passive immunization) are shown. Eight mice were used for each group, with the exception of the control groups in the “Freund's adjuvant” and “passive immunization” panels, in which 16 mice were used, and the RrgA-RrgB-RrgC (A+B+C) group in the “high-dose challenge” panel, in which 5 mice were used. (A) Bacteremia at 24 h postchallenge. Circles indicate numbers of CFU per ml of blood for single animals; horizontal bars indicate the geometric mean for each group; the dashed line indicates the detection limit (i.e., no CFU were detected in blood samples at levels below the dashed line). (B) Mortality course. Diamonds indicate survival times in days for single animals; horizontal bars indicate the median survival time for each group; the dashed line indicates the endpoint of observation (i.e., animals with survival times above the dashed line survived at the endpoint); ctrl indicates mice receiving only the corresponding adjuvant plus saline; * and ** indicate P values of <0.05 and <0.01, respectively (one-tailed Mann-Whitney U test), for comparison with the corresponding control groups.