ETIOPATHOGENESIS OF DISEASES CAUSED BY CLOSTRIDIUM DIFFICILE

Clostridium (C.) difficile is a typical representative of the genus Clostridium. After colonization of the intestinal tract, toxigenic C. difficile strains are capable to produce two exotoxins, enterotoxin (toxin A) and cytotoxin (toxin B), which cause diarrhea and colitis. Toxin A binds to specific carbohydrate receptors on the surface of intestinal cells and this is the beginning of damages in the intestinal tract which include destruction of the villi epithelium, limiting membrane, intercellular connections (zonula occludens) and surface of the mucosa. If only toxin B is injected into intestinal cells, it does not cause damage nor increased fluids secretion. Probably, the reason for this is the inability of the toxin to bind to the cell membrane receptor in the intestinal tract under normal physiological conditions. Toxigenic strains of C. difficile can be found in the intestines of healthy people, without any symptoms or clinical signs (asymptomatic colonization). However, in people with risk factors, they can cause diarrhea of varying severity and life-threatening pseudomembranous colitis. These diseases are known as C. difficile associated disease - CDAD