Figure 3. Passive immunization with SAvac-pcAb correlates with reduced bacterial burden and decreased pathology.

(A,B) Bacterial loads in the blood, spleens, and kidneys of mice intravenously immunized with SAvac-pcAb, negative control pcAb and PBS were determined 1 (A) and 3 days (B) after infection with 5 × 10⁸ CFU of MRSA252. Each group includeed 5 mice. Data were presented as box plots, with the median and interquartile ranges as indicated. The differences between vaccinated and control mice were indicated as p-value. (C) Gross pathology of different organs from mice immunized with SAvac-pcAb and PBS with representative figures from 5 mice per group were shown. Arrows indicate typical staphylococcal abscesses in the organs. (D,E) Hematoxylin-eosin-stained kidneys (D) and lung (E) from mice immunized with SAvac-pcAb and PBS. 3 days after infection and immunization, kidneys and lungs were harvested and stained. Representative histopathological sections from 5 mice per group were shown (magnification = 100 X). Arrows indicated inflammatory cell infiltration.