FIG 5.

Serological immune responses in A. nancymaae. Animals (9 to 10/group) were immunized i.d. with 129 μg chimera with or without 1 μg LT(R192G) or PBS on days 0, 14, 28, and 84 (arrows below x axis) and challenged on day 98 with 4.95 × 10¹¹ CFU of ETEC strain H10407 (vertical dashed line). (A) Anti-CfaE IgG antibody titers; (B) anti-CfaE IgA antibody titers; (C) anti-LTB IgG antibody titers; (D) anti-LTB IgA antibody titers. ELISA results (panels A to D) are shown as mean log₁₀ titers ± SD. (E) Hemagglutination inhibition titers with CFA/I⁺ ETEC strain H10407 (median ± interquartile ranges). Horizontal dotted lines denote the limit of detection for each assay (see Materials and Methods). Statistical comparisons were performed by one-way ANOVA and Tukey’s post hoc test on data collected from day 42 and 98 sera. #, P < 0.05, and ###, P < 0.001 for comparisons between chimera and PBS groups; §, P < 0.05, and §§§, P < 0.001 for comparisons between chimera with LT(R192G) and PBS groups; *, P < 0.05; **, P < 0.01; and ***, P < 0.001 for comparisons between chimera and chimera with LT(R192G) groups.