Which of the following is TRUE about prion diseases?

Prion diseases are a unique class of pathological conditions characterized by the presence of prions, which are misfolded proteins that induce abnormal folding of normal cellular proteins. This misfolding leads to a cascade of events that ultimately results in neurodegeneration. The infectious nature of prions means that they can be transmitted between individuals or species, often through contaminated tissues or fluids.

The neurodegenerative aspect of prion diseases is due to the accumulation of these abnormal proteins in the brain, which leads to severe damage and dysfunction of neural tissue, manifesting in a variety of symptoms such as cognitive decline and motor difficulties. Therefore, the statement about prion diseases being infectious and causing neurodegeneration accurately reflects the core characteristics of these diseases, highlighting both their transmissibility and their impact on the nervous system.

Other choices misrepresent prion diseases, as they are not caused by bacteria, cannot be treated with antibiotics, and do not primarily affect the immune system. In fact, prion diseases often have a minimal initial impact on immune function compared to their drastic effects on the nervous system.