Anatomical and histological characterization of ileal and jejunal Peyer's patch in lesser mouse deer (Tragulus javanicus)

Enterohemorrhagic Escherichia coli pathogenesis: role of Long polar fimbriae in Peyer's patches interactions

Enterohemorrhagic Escherichia coli (EHEC) are major food-borne pathogens whose survival and virulence in the human digestive tract remain unclear owing to paucity of relevant models. EHEC interact with the follicle-associated epithelium of Peyer’s patches of the distal ileum and translocate across the intestinal epithelium via M-cells, but the underlying molecular mechanisms are still unknown. Here, we investigated the involvement of Long polar fimbriae (Lpf) in EHEC pathogenesis. Of the 236 strains tested, a significant association was observed between the presence of lpf operons and pathogenicity. In sophisticated in vitro models of the human gastro-intestinal tract, lpf expression was induced during transit through the simulated stomach and small intestine, but not in the colonic compartment. To investigate the involvement of Lpf in EHEC pathogenesis, lpf isogenic mutants and their relative trans-complemented strains were generated. Translocation across M-cells, interactions with murine ileal biopsies containing Peyer’s patches and the number of hemorrhagic lesions were significantly reduced with the lpf mutants compared to the wild-type strain. Complementation of lpf mutants fully restored the wild-type phenotypes. Our results indicate that (i) EHEC might colonize the terminal ileum at the early stages of infection, (ii) Lpf are an important player in the interactions with Peyer’s patches and M-cells, and could contribute to intestinal colonization.

Ileal and jejunal Peyer's patches in buffalo calves: Histomorphological comparison

Aim:

The present study was aimed to elucidate the histomorphology of ileal and jejunal Peyer’s patches in the small intestine of buffalo calves and their structural comparison.

Materials and Methods:

The study was conducted on neonatal (n=10) and pre-pubertal (n=10) buffalo calves. The age of the postnatal buffalo calves was estimated by their temporary and permanent dentition.

Results:

The study revealed that several layers of oval to elongate elliptical lymphoid follicles were observed in submucosa on the anti-mesenteric side in the ileum of early neonatal calves. However, the follicles at this age, in jejunum were of all shapes present within one layer. The interfollicular space was occupied by the interfollicular tissue, which was diffuse and wider around jejunal lymphoid follicles as compared to ileal lymphoid follicles. However, toward the pubertal stage, the number of layers of lymphoid follicles was reduced in ileum due to involution while it remained similar in number in jejunum at this stage.

Conclusion:

The ileal Peyer’s patches were found to have started involution more or less around reaching puberty, whereas the jejunal Peyer’s patches appear to be functional throughout the lifespan of the animal.