Figure 11: IgG binding from human leptospirosis immune serum to L. interrogans. Bacteria were coated onto microtiter plates (25 × 106 leptospires/well) and IgG was bound by incubating bacteria 50% nonimmune human sera (NHS) or confirmed paired leptospirosis patients sera: MAT negative (MAT−) or MAT positive (MAT+). Bacteria were treated with PBS, 40 μg/mL PLG (PLG), 5 μg/mL uPA (uPA), or PLG + uPA (Pla). Presence of human IgG deposited on leptospires was determined by ELISA using Fc-specific anti-human IgG antibodies. Bars represent the mean absorbance values at 492 nm ± the standard deviation of three replicates for each experimental group and are representative of two independent experiments.