Question

The causative agent of Creudzfeldt-Jakob disease is

• A. Cronobacter sakazakii
• B. Cryptosporidium
• C. Citrobacter freundii
• D. Prion

Hint:

Prion Diseases (TSEs):
Humans = Creutzfeldt-Jakob Disease (CJD vCJD) & Kuru.
Cattle = Bovine Spongiform Encephalopathy (BSE Mad Cow Disease).
Sheep = Scrapie.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Transmissible Spongiform Encephalopathies (TSEs): Creutzfeldt-Jakob disease (vCJD in humans) and Bovine Spongiform Encephalopathy (BSE Mad Cow Disease in cattle) are caused by infectious, misfolded, proteinaceous particles termed prions ($ ext{PrP}^{ ext{Sc}}$).
Key Formula or Approach:
\[ \text{Prion Protein: Cellular } \alpha\text{-helical PrP}^\text{C} \xrightarrow{\text{Misfolding}} \text{Infectious } \beta\text{-sheet Rich } \mathbf{PrP}^{\mathbf{Sc}} \implies \text{Neurodegeneration (vCJD/BSE)} \]

Step 2: Detailed Explanation:
In neuropathology, veterinary public health, and zoonotic diseases:
- Creutzfeldt-Jakob Disease (CJD variant CJD) in humans, alongside Bovine Spongiform Encephalopathy (BSE 'Mad Cow Disease') in dairy and beef cattle, belongs to the family of fatal Transmissible Spongiform Encephalopathies (TSEs).
- The causative infectious agent is a Prion (D) (Proteinaceous Infectious Particle, discovered by Stanley Prusiner, 1982).
- Prions lack nucleic acid (no DNA or RNA) and consist entirely of an abnormally folded, $\beta$-sheet-rich isoform ($\text{PrP}^{\text{Sc}}$) of the host glycoprotein $\text{PrP}^{\text{C}}$ that is extremely resistant to heat, proteases, formalin, and standard pasteurization/sterilization autoclaving temperatures.

Step 3: Final Answer:
Therefore, the causative agent is Prion, matching option (D).