What virus does not have to be uncoated in the host cell?
What virus can replicate in an all ready replicating cell?
Where does viral DNA and RNA replication take place in a host cell?
- DNA = nucleus
- RNA = cytoplasm
7 viral methods of transmission? ADIF VIT
- Direct contact
What are the two virion nucleic acid packaging methods?
- Extended (loose) NA form: Influenza
- Condensed (tight) NA form: Adenovirus
4 biological properties of viruses?
- Host range
- Tissue tropism
What 5 diseases are strong viral risk factors for cancer?
- EBV (burkitt's lymphoma)
- Hep B & C
- Herpes type 8
- T-cell lymphotropic type 1
What is a non-lytic virus-host interaction?
Prophage that is living off of the host but not killing it
What is bacteriophage lysogeny?
The viral DNA is replicated every time the bacterial DNA is replicated
What is another term for lysogeny?
What happens with lysogeny w/ cAMP high and cAMP low?
- High = Lysogeny
- Low = Lytic cycle
What is another term for Lysogeny termination? How does it work?
- ***Prophage induction
- - If cell is dying or low on resources, the virus enter the lytic cycle to kill the cell and leave to find another host
Which drug is a strong prophage inducer?
What is special about persistent infections?
Long, active life in host but different from lysogeny, although not fully understood
Three types of persistent infection?
- 1) Latent: virus gone once disease is over
- 2) Chronic: virus still around after disease, Hep B
- 3) Transforming:virus turns cancer, HPV
3 viral modifications, CPE, in host
- 1) Inclusion body: replication in one small area, RABIES
- 2) Syncytia formation:giant cell formation, evade immune system
- 3) Nuclear alterations: ring structure, PLASMID
Three main methods to help ID a virus?
- 1) Direct examination: microscope, CPE, ab, antigens, etc...
- 2) Culture: egg, plaque, whole animal
- 3) Pt serum:ab test
Most popular method of viral culturing?
Pock formation in eggs
What method is used to culture prions?
Death/pathology of organism
What Ab is present during viral infections and how high should it be?
IgM, 4xs higher
Four methods of controlling viral spread?
- Vaccination: MMR, etc...
- Passive immunization: Abs for disease
- Antiviral agent (toxic)
What is different about a prion?
- Higher proteins
- No genome
- easily spread
Name three common Prion diseases
- Mad Cow
- Scrapie in sheep
Replication pattern diff b/t viruses and prions?
- Viruses = assembly line
- Prions = chain rxns