Fig 3.

Bacterial and toxin levels postchallenge. (A) Quantitative bacteremia, A 100-μl volume of whole blood was plated in triplicate on TSA. In addition, 10-fold serial dilutions were performed by transferring 100 μl of whole blood or the previous dilution into 900 μl of PBS. A 100-μl volume of each dilution prepared was plated in triplicate on TSA. Plates were incubated at 37°C for 16 to 24 h, bacterial colonies were enumerated, and the corresponding concentration (CFU/ml) was calculated. (B) PA levels measured by ELISA. Plates were read, and the data were analyzed by using a 4PL model to fit the eight-point calibration curve. The PA concentrations in samples were determined by computer interpolation from the plot of the reference standard curve data.