FIG. 3.

Guinea pigs infected with B. anthracis strain Ames generate EsxB, EsxP, and EsxW IgG-specific antibodies. Spores, suspended in 0.1 ml of sterile water, were injected subcutaneously into the loose subdermal tissue of the hind leg of animals. At 48-h postinfection animals were treated with antibiotics to prevent the development of an acute disease. Serum was collected 14 days postinfection and analyzed for the presence of EsxB-, EsxP-, EsxW-, and PA-reactive antibodies; IgG titers were determined in triplicate by ELISA and are reported as absorbance values at 405 nm.