chapter  19
12 Pages

The Role of Negatively Charged Surface Polysaccharide in Adherence of Escherichia Coli Strain Rdec-1 to Gut Epithelial Cells in the Rabbit

WithJ. Robert Cantey, Lindsey R. Inman

A striking feature of the disease is the manner in which the bacterium adheres to mucosal epithelial cells. Ruthenium red will stain negatively charged polysaccharides for visualization by electron microscopy, but it will not prevent collapse of the polysaccharide during the dehydration process. The polysaccharides or glycocalyx, consisting of O antigen and the negatively charged polysaccharide were partially purified and electrophoresed against ruthenium red. Tissues of rabbits with Rabbit Model of Escherichia coli diarrhea, stained with ruthenium red, confirmed the specificity of ruthenium red for microvillar glycocalyx of mucosal epithelial cells and bacterial negatively charged surface polysaccharide. The bacterial glycocalyx was visualized as a dense, flocculent, or fuzzy material of amorphous structure in tissues treated with antisurface polysaccharide serum. The bacterial polysaccharides clearly fill the space between the bacterium and the microvilli and extend to two adjacent bacteria as well. This space was filled with ruthenium red in earlier micrographs.