Virology Flashcards
2 Replication Enzymes Viruses may have to carry
RNA-dependent RNA pol
RNA-dependent DNA pol (reverse transcriptase)
Defective Virus
Doesn’t have a complete genome for replication/full coat synthesis so needs complementation of helper virus
2 Virus Morphologies
Cubic icosahedral
Helical
4 Differences between Naked Capsid and Pathologies
Environmentally stable vs. labile
Spread by cell lysis vs. budding
Spread easily on fomites/small droplets vs. large droplets or transfusions/transplants
Ab response vs. mainly cell mediated, which causes the damage in enveloped
4.3 Kinds of Infections
Inapparent
Acute - localized, generalized, congenital
Persistent
Transformation
Localized vs. Generalized Infections (3)
Localized just gets into portal of entry and replicates/spreads/sheds
Generalized can move through bloodstream or (less common) nerves to target organs and shedding site
Rabies
Generalized infection spreads through nerves to CNS, but takes a year so vaccine works after exposure
3 Kinds of Persistent Infections
Latent
Chronic
Slow
3 Differences b/w Latent, Chronic, and Slow Diseases (Primary Acute Infection, state of persistent virus, subsequent disease)
Yes - Noninfectious - Recurrent disease w/ reactivated virus
Yes - Usually infectious - chronic or recurrent
No - Infectious - Progressive
Prions
Just proteins that are resistant to everything and cause brain/dementia diseases
Prion Disease Formation
PrP mutates to scrapie form PrPsc, which can convert normal PrPs to PrPsc. Many PrPsc can seed polymerization into beta amyloid deposits
3 Kinds of CJD Cases
Sporadic, inherited, infectious
Stages of Prion Disease
Infection, LONG latency period, short prodrome period (just before major symptoms), short dementia period to death
5 Prion Disease and What they Target
CJD - cerebral cortex
Kuru - cerebellum
Grestmann-Straussler-Schneinker - cerebellum
Fatal Familial Insomnia - thalamus
Bovine Spongiform Encephalopathy - brain stem
