FIG. 5.

Levels of T. cruzi antibodies elicited in mice inoculated with either L16 clone or CL Brenner WT T. cruzi. Dispersion diagrams of antibody levels in control (untreated) animals and those inoculated with 10³ CRF of the L16 clone or the WT strain. Serum samples were taken at 6 (A) and 12 (B) months postinoculation. The results are expressed as the ratio of the absorbance of each serum sample at a 490-nm optical density (OD) to the cutoff value. Dotted lines indicate the cutoff adopted for positivity, calculated as the mean of the values determined for the controls (Cont.) plus three times the standard deviation. Each symbol represents a mouse. Neg, negative serum standard; Pos, positive serum standard. L16-inoculated mice showed significantly reduced antibody titers compared to those of mice inoculated with WT strain. (P values of L16 versus WT mice were 0.0031 [A] and 0.004 [B]).