Kinetics of fluid accumulation and pathology in V. parahaemolyticus-infected infant rabbits.
(A) Concentration (cfu g−1) of V. parahaemolyticus recovered in distal small intestine homogenates at different times after inoculation. Data points represent individual rabbits; bars represent geometric means. Open boxes represent the limit of detection for samples from which no cfu were isolated. Groups were compared using one-way ANOVA with Boneffoni's multiple comparison post-test (*** P<0.001). (B) Fluid accumulation ratio (mean ± SEM) in the distal small intestine of rabbits at various times PI. Data were compared to uninfected rabbits using one-way ANOVA with Boneffoni's multiple comparison post-test (*** P<0.001). (C–D and F–G) Representative H&E-stained sections from the distal small intestine of infected rabbits at 18 hr (C), 28 hr (D, F) and 38 hr PI (G) showing the frequency and size of attached bacterial clusters as well as histological changes. Arrowheads in C and D point to bacterial microcolonies and long arrows indicate luminal heterophils; in F, arrowheads point to extruding epithelial cells with V. parahaemolyticus at their base, and in G, arrowheads point to extruding cells and long arrows point to cytoplasmic fragments. Scale bars are 100 µm and 20 µm in C–D and F–G, respectively. (E) Small intestinal tissue sections from rabbits infected with V. parahaemolyticus expressing GFP (green) counterstained with phalloidin (red) and DAPI (blue) to detect F-actin and nuclei acid, respectively.
