Blood in stool is seen in all except -

Ans. is 'a' i.e., Vibrio cholerae * Based on the depth of intestinal invasion, there are different clinical manifestations of infection with organisms causing diarrhea:1) No cell invesion (noninflammatory)# The bacteria bind to intestinal epithelial cells but do not enter the cell.# Diarrhea is caused by the release of enterotoxins.# Watery diarrhea with no fecal leukocytes and no systemic symptoms (e.g. fever) occurs.# Organisms are1. V. cholerae4. Clostridium perfringens7. Cryptosporidia10. Adenovirus2. ETEC5. B. cereus8. Microsporidia 3. Staph, aureus6. Giardia9. Rotavirus 2) Invasion of the intestinal epithelial cells (Inflammatory)# The organisms have virulence factors that allow binding and invasion into cells.# Toxins may be then released that destroy the cell.# The cell penetration results in a systemic immune response with fecal leukocytes as well as fever.# The cell death results in RBC leakage into the stool (dysentery).# Organisms are:-1. Shigella4. EHEC&EIEC7. C. difficale2. Salmonella Sp.5. Vibrio parahemolyticus8. E. histolytica3. Campylobactorjejuni6. Yersinia enterocolitica 3) Invasion of lymph nodes and blood stream (Penetrating)# Along with abdominal pain and diarrhea containing WBCs and RBCs, this deeper invasion results in systemic symptoms of fever, headache and leukocytosis.# Examples are - 1. Salmonella typhi, 2. Yersinia enterocolitica, and 3. Campylobacter jejuni.