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16 Cards in this Set
- Front
- Back
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Influenza A virus
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enveloped, minus strand RNA, multi segmented
Orthomyxovirus (minus need own RNA poly) replicates in nucleus uses 5' host mRNA as template/ primer for mRna synth (endonuclease) alternative splicing- 8 genes and 10 proteins |
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Influenza A Life cycle
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Hemaglutinnin bind sialic acid- endocytose
pH decrease, viral acid fuse with endosome membrane fuse with nucleus, replicate and translate fusion with outer membrane and budding via neuramindase |
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Membrane fusion
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pH dependent due to decrease in pH
virus becomes acidified using M2 ion channel (block with amanatidine, rimantadine. |
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Hemoglutinin changes
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Cleaved by protease for maturation
decrease in pH causes conformation change that allow for fusion with endosomal membrane/ nucleus - exposes the hydrophobic regions |
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Viral genetics
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Increase in Rna polymerase error
multi-segmetned genes can reassort (need multi) antigenic drift vs. shift |
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Antigenic Drift
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pt mutations that cause subtle/significant changes in virus DNA. changes the strain and will require new vaccine. how strain changes from season to season
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Antigenic Shift
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wholesale changes in viral DNA
caused by reassortment of genes (need segmented) little or no pre-existing immunity can lead to pandemic occur in animal reservoir |
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Tropism
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Virus and host having necessary factors that can complement one another to create a pathogenic disease/ response
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Influenza virus vaccine
neutralizing antibodies or cell mediated immunity |
live attenuated virus, purified proteins- Flumist-, passage/ growth at low temperatures
inactivated vaccine- dead whole virus- trivalent Na and HA want to vaccinate against |
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Respiratory Syncytial Virus
(RSV) paramyxovirus (affect everyone by age 2) |
`enveloped, negative mRNA, single gene
Subgenomic DNA- uses -RNA to make mRNA with own polymerase- create multiple proteins based on start and stop sites Replication- genome to anti to genome Direct entry- pH dependent |
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Rhinovirus
picornaviruses |
non enveloped, single strand, mRNA positive
3 species, 100 serotypes Receptor mediated endocytosis, escape from vesicle, in cytosol use host ribosomes via IRES drivien to form polyprotein (break with encoded proteases) Viral rep/ packaing |
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Adenovirus
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non enveloped, double stranded pos, linear DNA genome
50 types, cause ocular or GI infection ( not resp) replicates in nucleus |
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Corona virus
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enveloped, large + genome
uses polyproteins and subgenome think Sars |
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Replication in nucleus
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Influenzae A(-, nucleus host cell RNA) , adeno virus (+, double stranded) , RSV (enveloped single strand, subgenomic)
rhinovirus (single + host cell), coronavirus (double +) |
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Non enveloped
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Non enveloped
Rhinovirus Adenovirus |
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Positive
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Rhinovirus, adenovirus, coronavirus
PRAC |
