Micro 56: Prion Diseases

This episode concludes the virology section with an agent that defies traditional classification: the prion. Drawing from Murray’s Chapter 56, it explores infectious disease caused not by bacteria or viruses, but by misfolded protein.Prions lack nucleic acid. Instead, a normal cellular protein (PrPᶜ) undergoes conformational change into a pathogenic isoform (PrPˢᶜ). This altered structure induces further misfolding in neighbouring proteins, creating a cascade of abnormal accumulation.The result is spongiform degeneration of neural tissue, leading to rapidly progressive neurodegenerative disease. Conditions include:* Creutzfeldt–Jakob disease (sporadic, familial, variant)* Kuru* Gerstmann–Sträussler–Scheinker syndrome* Fatal familial insomniaPrions are uniquely resistant to conventional sterilisation methods, requiring specialised decontamination protocols.Conceptually, prion disease challenges central assumptions of microbiology - infection without genome, replication without nucleic acid synthesis. Clinically, diagnosis is difficult and treatment remains supportive.Key Takeaways* Prions are misfolded infectious proteins* No nucleic acid is involved* Disease involves progressive neurodegeneration* Transmission may be sporadic, inherited, or acquired* Standard sterilisation methods are insufficient This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit drmanaankarray.substack.com/subscribe