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32 Cards in this Set
- Front
- Back
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What are the genera of influenza?
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Influenza A, B, and C (Family: orthomyxoviridae)
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What is the capsid symmetry of influenza?
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helical
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What is significant about the genome of influenza?
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It's segmented.
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What are some critical viral proteins of influenza?
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HA, NA, M2
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What does hemaglutinin do?
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Causes agglutination of red blood cells
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Why do influenza infections manifest themselves in the lungs?
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HA binds to α-2,6 linkages of a type of sialic acid present in the upper respiratory tract after it's precursor is cleaved by trypsin.
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Where do avian strains of HA bind?
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α-2,3 linkages of sialic acid (in humans these are in lower respiratory tracts)
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What is the function of the M2 protein?
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It acts in the endosome as a protein pump which acidifies the vesicle and causes uncoating of the capsid. (Prior to this it causes a conformational change in HA that leads to the fusion of the endosome and the target cell membrane.)
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What is the function of NA?
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NA (neuraminidase) cleaves sialic acid as the virion leaves the host cell, allowing it to bleb off
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Why does antigenic drift occur in influenza?
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it occurs due to the lack of proofreading capability of RNA pol
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Why does antigenic shift occur in influenza?
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segmented genes get reassorted in a mixing vessle such as a swine (a mixture of human and avian segments)
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What is the classification of influenza genomic material?
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ss -RNA
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How is influenza typically assayed?
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ELISA
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What are the viral properties of paramyxoviridae?
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helical capsid, ss -RNA, unsegmented, enveloped
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What type of infections does the parainfluenza virus cause?
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respiratory disease, bronchitis, bronchopneumonia, and croup
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What is a common CPE of a paramyxo virus?
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syncytia formation with giant nucleated cells
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What is the TIV?
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the trivalent inactivate vaccine (composed of two components of influenza A and one of B)
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What is RSV?
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a paramyxovirus that causes respiratory infections primarily in children in the winter months; respiratory syncytial virus
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What are the viral properties of the coronavirus?
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helical capsid, ss +RNA, unsegmented, enveloped (petal shaped projections resembling a solar corona)
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What are some commone illnesses associated with coronavirus?
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common cold & SARS!
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What is the CPE of SARS?
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multinucleated syncytial giant cells
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What are the viral properties of adenoviridae?
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icosohedral capsid (with fiber protein), DS DNA, linear, non-enveloped
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What are some of the viral infections associated with adenoviridae?
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acute respiratory infections and acute respiratory disease
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What is significant about the fibers of adenoviridae?
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There are a number of serotypes that cause different diseases including epidemic keratoconjuntivitis.
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What is unique about rhinovirus?
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It belongs to the picornaviridae family, but actually causes the common cold (rather than a GI infection).
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Whater are the viral properties of picornaviridae?
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icosahedral capsid, ss + RNA, non-enveloped, VPg
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What type of infections can enteroviruses cause?
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all different kinds (polio is actually an enterovirus)
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What is significant about norovirus?
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it has a hearty capsid, low infectious dose, and survives freezing and tempratures of 60 C, often associated with mass infection on cruise ship due to a food preparer carrier
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What are the viral properties of rotavirus?
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it has a double icosahedral capsid!, dS RNA!, segmented, and is non-enveloped
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What types of infections does rotavirus cause?
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diarrhea in infants (rotavirus A) due to a capsid protein that has cholera like acitivities (95% of infants get infected)
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What are some laboratory diagnoses of rotavirus?
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fast test
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What are the some vaccines for rotoavirus?
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RotaTeq and RotaRix
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