Fig. 7
Clinical and histopathological aspects of E. coli strains’ administration. Mice (n = 8) were administered either sterile PBS, CEC15 (1010 CFU/mice/day) or EcN (1010 CFU/mice/day) for 12 days with administration of 5-FU (300 mg/kg) or PBS on the day 10. The results above show the weight variation (day 10-13) (A) and the morphological characteristics, such as intestinal permeability (B) and tissue neutrophilic infiltration (C). The structural damage caused by the 5-FU administration and the partial protection promoted by CEC15, as well as the unmodified morphology on the control groups and of the EcN treatment after mucositis induction can be observed on the slides (D), dyed with hematoxylin and eosin (Magnification of 20X). The histopathologic inflammatory scoring based on villous atrophy, rupture of the surface enterocyte borders, depletion of calyceal cells, loss of crypt architecture, destruction of crypt cells, abscess formation in the crypts, infiltration of lymphocytes and polymorphonuclear cells, dilation of capillaries and lymphatic vessels, and thickening with edema formation in the submucosa and external muscle layers. Histological features were scored on a scale of 0 (average) to 3 (max damage), and points were summed for each animal accordingly (E), villus height (F), and the depth of the crypts (G) were measured from these slides. Statistical analyses were performed by One-way ANOVA with Tukey’s post-test on GraphPad Prism 7.0. * p<0.05; ** p<0.01; *** p<0.001; **** p<0.0001. NC: negative control; CEC15: healthy CEC15-treated; EcN: healthy EcN-treated; MUC: mucositis control; CEC15/MUC: mucositis CEC15-treated; EcN/MUC: mucositis EcN-treated