Virology 2 Flashcards
What is the replication strategy of ssDNA viruses (e.g., parvoviruses)?
Uses host RNA polymerase to generate viral mRNA and which is then translated into proteins
In order to replicate genome uses host DNA polymerase
What is the replication strategy of dsDNA viruses?
Uses host RNA polymerase to generate mRNA and then proteins
In order to replicate genome can use either host or viral DNA polymerase
What is the replication strategy of ssRNA (+)?
already in positive mRNA form just uses host ribosomes to translate into proteins
in order to replicate genome uses viral RNA dependent RNA polymerase
*occurs in the cytoplasm bc no splicing necessary*
What is the replication strategy ssRNA (-)
*host ribosomes don’t recognize (-) RNA*
-Must bring into host along with it, viral RNA polymerase, to make mRNA
In ordert to replicate genome, again uses viral RNA polymerase
What is the replication strategy of dsRNA?
*rotavirus*
essentially the same mechanism as ssRNA(-) bc uses viral RNA polymerase to synthesize protein and replicate genome
What is viral reverse transcriptase
RNA dependent, DNA polymerase
What is the replication strategy for rertroviruses?
Uses viral reverse transcriptase to make dsDNA then gets integrated into the nucleus of the host cell (provirus). After this occurs the “host” polymerase is used to transcribe the dsDNA into mRNA –>proteins
In order to replicate genome uses same process^
How does an enveloped virus exit a cell vs a naked virus?
Budding from membranes
vs
cell rupture
What are the 4 types of infections?
subclinical- most common with no apparent disease
acute localized
acute generalized
persistent
In acute generalized infections, what is primary and secondary viremia?
Primary- spreads virus to central focus- virus then replicates at central focus; virus spreads to blood stream from central focus
Secondary- Spread to the Target organ => this is when disease occurs
*symptoms experienced before disease known as prodrome
Acute infection
Rhinovirus
rotavirus
influenza virus
*days to weeks
Persistent infection
HIV type 1
forever
always detectable
*high rate of replication until treatment
Latent infection
Herpes simplex virus
reactivating infection
only detectable when reactivated
Slow virus infection
Measles virus SSPE
HIV w/treatment
What are the acute infections w/late complications?
Measles => subacute sclerosing panencephalitis
Rubella => progressive rubella pancephalitis
