Evidence That the Human Disease Arising from Shiga Toxin Production

Evidence that the human disease arising from Shiga toxin production may be co-incidental comes from the observation that:

A) Shiga toxin production stimulates iron uptake by host cells
B) Shiga toxin production increases the survival of E.coli which would be consumed by Tetrahymena protozoa
C) Shiga toxin is not expressed in bovine animals
D) Shiga toxin only affects amaoeboid organisms found in air conditioning units
E) Shiga toxin is bacteriophage-encoded.