Tiwari – Microbiology – Flashcards
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| Why is HPV heterogenous? |
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| some cause cancer, some don't |
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| gardisil is made from? |
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| HPV capsid protein L1 |
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| HPV causes cancer how? |
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| E6, E7 hijack p53 |
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| pleconaril |
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| binds hydrophobic pocket of vp1 capsid of rhino virus |
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| examples of helical viruses |
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| influenza, rabies, tobacco mosaic, no DNA viruses are helical |
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| icosahedral |
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| 20 triangle capsomers |
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| corona virus |
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| largest genome of any rna virus, 2nd leading cause of common cold |
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| herpes virus |
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| polyhedral |
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| naked icosahedral |
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| adenovirus, polio |
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| naked helical |
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| tobacco mosaic |
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| enveloped icosahedral |
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| herpes |
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| enveloped helical |
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| ifluenza, measles |
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| enveloped complex |
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| poxvirus |
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| matrix=, tegument= |
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| capsid to envelope and proton pump so virus can release genome if endocytosed, halt host protein synth. |
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| Type I |
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| dsDNA, replicate in nucleus except for pox which does in cytoplasm and has its own stuff |
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| Type II |
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| ssDNA, + or -, reps in nucleus, involves formation of comp strand, parovirus |
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| Type III |
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| dsRNA, segmented genome, each transcribed separetely to form monicistronic mRNA, reovirus |
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| Type IV |
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| ssRNA, +, no tag-along polymerase, naked rna is infectious, rhinovirus |
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| Type V |
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| ssRNA, -, need a tag-along polymerase, paramyxovirus, orthomyxovirus |
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| Type VI |
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| ssRNA, +, retrovrius, diploid, DNA intermeidate |
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| Type VII |
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| dsDNA, with rna intermediate, hep b |
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| size range |
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| 20nm-200nm, parovirus smallest at 22nm |
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| corona virus binds? |
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| ICAM I with S protein |
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| Influenza activity mediated by? |
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| hemigglutinin-into cell, binds sialic acid neuraminadase-helps virus get out has segmented genome |
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| adenovirus specifics |
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| fiber knobs and pantone base, uses integrin and coxxecci for binding |
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| circular of linear? |
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| HPV/Hep B have circ. genome Herpes is linear and turns circ. once it infects |
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| largest DNA genomelargest RNA genomesmallest Genome? |
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| poxviradae(380kb) coronaviradae(30kb) M2 bac.phage (3kb) |
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| direct penetration |
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| dengue, polio = naked |
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| membrane fusion |
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| measles, mumps = enveloped |
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| endocytotic mechanism? |
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| adenovirus, herpes = naked or enveloped |
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| phagocytic entry |
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| herpes |
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| how to determine virus receptor |
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| receptor knockouts, compete with soluble recep, antibody blocking |
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| order of viral entry |
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| binding(ionic)-attachment-fusion-transport |
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| nature of receptors |
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| sugar, protein, Ig-like, Cell-signaling |
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| rhinovirus influenza herpes adenovirus hiv rsv polio hpv |
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| icam sialic acid heparan sulfate, nectin 1, hvem coxackie a.v. receptor cd4, ccr5 heparan sulfate cd155 integrins |
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| HIV binding attachment |
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| v3 loops of gp120 to CD4, then gp41 helps with fusion |
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| herpes binding, so forth |
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| binding: gC and gB to HS fusion: gD to HVEM, Nectin 1-2, 3-0-S HS |
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| viroids |
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| ssRNA without a coat, plant pathogens |
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| Influenza M1 and M2 |
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| M1 helps with budding M2 causes fusion and release of virus from endosome through proton pumping |
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| amantadine |
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| influenza A uncoating |
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| Acylovir |
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| viral thymidine kinase activates it and thus only targets virus infected cells, herpes |
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| DNA Virus w/ > 100 serotypes DNA Virus w/ 1 serotype RNA Virus w/ > 100 serotypes |
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| HPV small pox rhinovirus |
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| Lysosomal function inhibitor |
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| ineffective against HIV and other viruses that don't need low pH for release from endosome/lysosome |
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| protease inhibitor |
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| inhibits protease from cleaving the polyproteins gag and pol so functional HIV viral particles cannot be assembled |
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| do rotaviruses need to b epartially digested by proteases to get into the cell? |
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| yes! |
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| only ssDNA virus? |
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| parvovirus |
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| Most DNA viruses use host RNA pol, which don't? |
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| poxvirus and hep b, but all have a viral encoded DNA polymerse |
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| some viruses use host cell DNA pol, and depend on cell for everything, which are they? |
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| parvovirus B19 and HPV, that's why they stick around |
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| Order of events for Herpes? |
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| Tegument proteins shut down host cell protein synthesis, DNA released into nucleus and gets transcribed to alpha mRNA that gets translated into alpha proteins, alpha reg proteins for back and initiate transcription again generating Beta mRNA and proteins, which then carry on |
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| Rolling Circle Model Bidirectional Displacement Synth Hairpin Mechanism |
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| HSV-1 SV40 virus adenovirus parvovirus |
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| Late events in Herpes rep? |
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| B proteins replicate viral genome by rolling circle model, gamma mRNA is turned into the gamma structural proteins, viral particles packaged in golgi and released |
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| SV-40 virus bidirectional replication? |
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| early and late transcription, early product includes T-antigen which unzips DNA in both directions |
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| Which RNA viruses have their own RNA to RNA polymerase? |
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| Polio, Influenza, respiratory syncytical virus, rabies, rubella, measles, hep a and c, ebola |
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| viruses using host RNA pol? |
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| HIV, Human T-cell leukemia virus |
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| RNA replication occurs in the cytoplasm of all RNA viruses except? |
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| Retroviruses, influenza, hep d |
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| + ssRNA Viruses? |
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| genome transcribed, get a polyprotein that is cleaved into its active parts, one of which is RDRP that makes a - strand that then gets turned into a bunch of + strand |
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| ssRNA - , and dsRNA +- viruses need? |
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| tag along RDRP |
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| Retrovirus genes? |
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| Gag=structural proteins Pol=protease, integrase, RT Env=envelop proteins Tat/Rev=regulatory proteins |
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| what is the human version of RT? |
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| telomerase |
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| HIV replication stages? |
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| RT makes DNA from one (of 2)strands of RNA, then RNaseH with ribonuclease activity removes RNA, then host cell DNA pol makes comp DNA strand, then it's integrated into host DNA by integrase. Proteases cleave the poly protein that is subsequnetly created |
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| viral exit? |
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| budding (enveloped) or lysis(naked) |
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| SV40 characteristics? |
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| monkeys, tumors |
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| red cheeks=eryhtema infectiosum, feline panleukopenia, fifth disease, depends on actively dividing cell? |
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| parvovirus |
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| HIV antibodies? |
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| against p24 capsid protein |
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| partial circular dsDNA genome? |
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| HBV |
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| only virus that produce genomic DNA by using RT with mRNA as template? |
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| hep b |
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| which virus needs a helper virus to donate its envelope proteins? |
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| hep d |
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| herpes virus that causes congenital abnormalities? |
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| Cytomegalovirus |
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| herpes virus ass. with Burkitts lymphoma, hairy leukopenia without giant cell formation? |
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| EBV |
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| Sites of LatencyHSV-1 HSV-2 VZV EBV CMV HHV-8 |
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| cranial sensory ganglia lunbar and sacral sensory ganglia cranial or thoracic sensory ganglia b cells circulating lymphoid or epithelial cells not known |
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| corona virus envelope derived from? |
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| ER |
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| what virus can be visualized with a light microscope? |
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| poxvirus |
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| cytopathic effect? |
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| visible changes from viral infection |
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| Visual changes in herpes infected cell? |
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| actin becomes disorganized |
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| Which viruses form syncytium and what is it? |
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| when an infected cell fuses with neighboring cells, murine leukemia virus and Respiratory Syncytial virus, leading cause of pneumonia in infants |
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| leading cause of corneal blindness? |
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| herpes sv 1 |
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| Tzanck Test? |
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| For herpes and vericella zoster (c. pox) |
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| If virus does not cause a cytopathic effect, what can you notice? |
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| Hemadsorption=attachment of RBCs to virus infected cell (influenza, parainfluenza) Interference=coinfect a cell that is infected with CPE causing Cozackieviurs with Rubella and mute effect pH indicator defensive identification: inclusion bodies--- rabies=negri bod. CMV=Owls Eye, Pap Smear=HPV, plaque formation=psuedo rabies, HSV |
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| Plaque Forming Units= |
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| Number of plaques/(dilution fac.Xvolume of diluted virus) |
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| Amplify viral genome for detection? |
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| if rna, use RT then PCR DNA product, otherwise just PCR |
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| QPCR= |
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| Real time pcr, extremely accurate |
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| How can engineering a virus tell u whether someone is infected, called Reporter virus detection? |
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| add gene for an enzyme (eg. B galac.) that converts something to a colored product |
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| Light microscopy for pox only. What about other stuff? |
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| Flourescent tags for flourescene microscopy |
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| What is virus neutralization? |
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| add antibodies to a virus to a culture, if virus in question is non-infective, then you got the right one |
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| Hemagglutination Inhibition? |
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| same as virus neutralization |
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| what is complement fixation? |
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| if antibodies present (ie + for virus), complement is fixed and no lysis is noted |
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| which viruses won't grow in cell culture? |
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| hep b, parovirus, papillomavirus, diarrheal viruses |
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| what are the fingerprints of CPE? |
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| cell rounding/detachment, synctia, loss of mitochondrial function, swelling of nuclei, DNA fragmentation |
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| What is the significance of F protein of RSV? |
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| F, fusion protein, causes RSV infected cells to form multinuclceated giant cells, or syncytia |
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| What is DEAFF test for? |
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| CMV flouresence detection of CMV early protein pp65 |
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| DFA for? |
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| herpes |
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| What transcript is expressed in HSV-1 latent phase? |
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| LAT is an unusual 2kb intron, detectable with in situ hybridization |
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| most commonly used reporter gene? |
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| GFP |
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| Types of inclusion bodies observed in viral infections? |
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| Negri bodies=rabies Owl eyes=cmv guarnieri bodies=small pox cowdry bodies= HSV and VZV |
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| what type of infection has prominent inclusion bodies? |
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| herpes simplex encephalitis |
