Which of the following toxins is not produced by a bacterium as a result of lysogenic conversion?

• A. Diphtheria toxin
• B. Prion protein
• C. Cholera toxin
• D. Shiga toxin

Answer: (B)

Verified step by step guidance

1. Understand the concept of lysogenic conversion: it occurs when a bacterium acquires new genetic traits, including toxin production, through the integration of a bacteriophage (a virus that infects bacteria) into its genome.
2. Identify which toxins are known to be produced by bacteria as a result of lysogenic conversion. For example, diphtheria toxin, cholera toxin, and shiga toxin are all encoded by genes carried on bacteriophages integrated into their respective bacterial hosts.
3. Recognize that prion proteins are not toxins produced by bacteria but are misfolded proteins associated with certain neurodegenerative diseases in animals and humans, and they are not related to bacterial lysogenic conversion.
4. Compare each toxin listed with the known mechanisms of production: confirm that diphtheria toxin, cholera toxin, and shiga toxin are all linked to lysogenic bacteriophages, whereas prion protein is not produced by bacteria at all.
5. Conclude that the toxin not produced by bacteria as a result of lysogenic conversion is the prion protein, since it is not a bacterial toxin but a protein associated with prion diseases.