What term is used for infectious agents composed of protein that can lead to neurodegenerative diseases?

The term refers to prions, which are unique infectious agents made entirely of protein. Unlike bacteria, viruses, or protozoa, prions lack nucleic acids (DNA or RNA) and are misfolded protein molecules that can induce abnormal folding of more normal cellular proteins. This misfolding leads to the accumulation of dysfunctional proteins in the brain, ultimately resulting in neurodegenerative diseases such as Creutzfeldt-Jakob disease and Bovine Spongiform Encephalopathy (commonly known as "mad cow disease"). Prions are notoriously resistant to standard methods of sterilization and can persist in the environment, contributing to their infectious capacity. Understanding prions is crucial in microbiology because they challenge traditional concepts of infection and disease transmission, emphasizing the importance of protein conformation in biological processes.