Table 1.
Escherichia coli strains.
Fig 1.
Fold change in IgG antibody titers when compared to control serum (from non-vaccinated rabbits) for various CFAs in rabbit serum.
Serum samples of each rabbit intramuscularly (triangles) or intradermally (circles) vaccinated with CFA/I/II/IV MEFA protein, with dmLT adjuvant, were titrated in ELISAs with CFA/I, CS1, CS2, CS3, CS4, CS5 adhesin, CS6 CssA recombinant protein, or CT (for LTB) as coating antigens. Rabbits were immunized twice, with a period of two weeks between doses. Mean and standard deviations are shown in black, individual fold changes in gray.
Fig 2.
Colonization of naïve rabbits with ETEC strains, showing location of the small intestine sampled (distal: blue, proximal: red).
Shown are plate counts for each rabbit (single points), with boxplots overlayed displaying the median and interquartile range in black. The strain of ETEC used for the challenge is listed at the bottom. ****: p < = 0.0001 when Student’s T-test performed with B7A.
Fig 3.
Mean CFU/g of ETEC strain B7A after naïve challenge, challenge followed by rechallenge, and vaccination followed by challenge.
The challenge and rechallenge dose were 1011 CFU of strain B7A. Mean CFU/g for each rabbit is plotted as circles, with the geometric mean of the treatment group displayed as a triangle. P values shown are the result of Student’s T-tests comparing mean CFU/g of all rabbits in each treatment group.
Fig 4.
Rabbit serum IgG titers for control and vaccinated animals.
Rabbit serum IgG titers (log10) to CFA/I, CS1, CS2, CS3, CS4, CS5, or CS6 adhesin and toxin CT (LTB) are shown in grey symbols. Serum samples of each rabbit IM vaccinated with CFA/I/II/IV MEFA protein, with dmLT adjuvant, were titrated in ELISAs with CFA/I, CS1, CS2, CS3, CS4, CS5 adhesin, CS6 CssA recombinant protein, or CT (for LTB) as coating antigens. Black symbols and bars in each group represent the means and standard deviations of IgG titers. Control serum is from non-vaccinated, non-challenged rabbits.
Fig 5.
Rabbit serum antibody adherence inhibition activity against ETEC CS6 (2423 ETP98066) or B7A strains.
CS6 and B7A bacteria adherent to Caco-2 cells (CFUs, in %) after incubation with rabbit serum samples from the control group (□) or the group IM vaccinated with CFA/I/II/IV MEFA protein (■). Boxes and bars represented means and standard deviations, *** indicates a p value of < 0.001.