Prions

Prions are infectious proteins that can cause disease by transforming normal proteins in the brain into abnormal, misfolded versions. Unlike bacteria or viruses, prions contain no genetic material—no DNA or RNA. When prions accumulate, they form stubborn, damaging structures that kill nerve cells, leading to neurological diseases like mad cow disease and Creutzfeldt-Jakob disease in humans. These diseases are often progressive and currently have no cure. Prions are notable for their resistance to standard sterilization methods, making them particularly challenging to eradicate once they contaminate environments or biological tissues.