Final answer:
Salmonella typhi does not produce exotoxins; it is known for endotoxins, while the other listed organisms produce various exotoxins.
Step-by-step explanation:
The organism that does NOT produce exotoxins among the options provided is Salmonella typhi. Salmonella typhi is known for producing endotoxins rather than exotoxins, which are typically associated with genera like Clostridium and Staphylococcus. Clostridium botulinum produces botulinum neurotoxin, Corynebacterium diphtheriae produces the diphtheria toxin, Clostridium tetani produces tetanus neurotoxin, and Staphylococcus aureus is known for its superantigens, including the toxic shock syndrome toxin.