Viruses/DNA viruses Flashcards
Reassortment
Viruses w segmented genomes exchange segments
- “high frequency recombination”
e. g. Influenza –> worldwise pandemics
Complementation
When 1 of 2 viruses that infects a cell has a mutation such that it makes a non-fxnal protein
-the Non-mutated virus will make a fxnal version and they can share it.
Phenotypic mixing
- 2 viruses infect cell at same time
- Genome of virus A gets partially/totally coated by virus B surface proteins
- Type B coat determins tropism/infectivity of hybrid virus
- -> Infxn –> Progen will then have type A coat bc it’s encoded in type A genetic material
Killed
Rabies
Influenza (IM)
Salk Polio (IM)
Hepatitis A
Live vaccines
Smallpox Yellow Fever Chickenpox/VZV Sabin's Polio (oral) MMR Influenza (NASAL)
recombinant vaccines
Hepatitis B (HBsAg) HPV (6, 11, 16, 18)
DNA viruses that are linear
All but Papilloma-, Polyoma-, Hepadnaviruses
CIRCULAR
DNA viruses that are double stranded
All but PARVOVIRUS
Positive stranded RNA viruses
I went to a RETRO (retrovirus) TOGA (togavirus) party where I drank FLAVored (Flavivirus) CORONA (Coronavirus) and ate HIPPY (hepevirus) CALIfornia (calicivirus) PICkles (picornavirus)
RNA viruses that are single stranded
All but REOVIRUS
double the naked, ds RNA trouble in REO Nevada!
Naked viral genome infectivity
- Infective: dsDNA (except Poxviruses and HBV) and +strand ssRNA
- Require polymerases in virion: -strand ssRNA and dsRNA
DNA viruses: replicate in the_____
Nucleus, all but Poxvirus
viruses that are Haploid
All of them (1 copy of DNA or RNA) except RETROVIRUSES (2 idential ssRNA=diploid)
Naked viruses
Give PAPP smears and CPR to a naked Heppy
Papillomavirus - DNA Adenovirus - DNA Parvovirus - ssDNA Polyomavirus - DNA Calcivirus - RNA Picornavirus - RNA Reovirus - RNA Hepevirus - RNA
RNA viruses: replicate in the ___
Cytoplasma, (excpet influenza and retroviruses)
Enveloped viruses acqure envelop from….
the Plasma membrane!
except HERPES which gets its envelope from the NUCLEAR membrane.
DNA viruses that are Icosahedral
All but POXvirus
DNA viruses (names)
DNA viruses are HHAPPPPy Hepadna Herpes Adeno Pox Parvo Papilloma Polyoma
Hepadnavirus
partail dds DNA, circular
Enveloped
e.g. HEPATITIS B (not a Retrovirus, but has reverse transcriptase activity)
-replication of HBV: double stranded DNA –> Template + RNA –> Double stranded DNA
(HEPadna for HEPatitis B)
DNA viruses that replicate in the nucleus
All but POXvirus (has it’s on DNA-dependent-RNA-polymerase
Adenovirus
dsDNA, linear, NAKED
- -> Febrile pharyngitis (sore throat, nasal congestion, enlarged cervical nodes)
- ->Pneumonia
- ->Conjunctivitis-PINK EYE (which you get from rubbing up against NAKED people)
Herepesvirus
dsDNA, linear, Enveloped
Papillomavirus
dsDNA, CIRCULAR, NAKED
=HPV –> warts (1,2,6,11), CIN, cervical cancer (16,18)
Parvovirus
ssDNA, linear NEG, NAKED. the smallest*
=B19 virus
–>aplastic crisis in sickle cell
–>”slap cheek” in children (5th ds),
–>Maternal –> Fetal: RBC destruction (hydrops fetalis), pure RBC aplasia
–> Adults: Rheumatoid arthritis that resolves spontaneously in few weeks (affects knees, ankles, metacarpal, PIPs - just like RA)
-attaches to rbcs by P antigen. Immature rbcs are more vulnerable, hence targets are: adult bone marrow and fetal liver
-viral replication –> cell death
Poxvirus
dsDNA, linear, Enveloped. Largest DNA virus*
=Smallpox
=Vaccinia –> Cowpox (“milkmaid’s blisters”)
=Molluscum contagiosum* (so large you could squeeze them out!)
Polyomavirus
dsDNA, CIRCULAR, NAKED
=JC virus–> progressive multifocal leukoenceophalopathy (PML) in HIV. causes demyelination by infxn of oligodendrocytes (faster >MS)
=BK virus –> transplant pts, targets Kidneys
JC: Junky Cerebrum. BK: Bad Kidney
Jesus Christ and Brian Kay are POLYamourous and don’t wear their wedding rings (naked dsDNA, circular)
HSV-2
dsDNA, linear, enveloped
- Sexual contact, perinatal
- -> Herpes genitalis, neonatal herpes (ulcerating vesicles), can cause Meningitis
- Dormant in the SACRAL ganglia
HSV-1
dsDNA, linear, enveloped
- secreted by respiratory secretions, saliva
- Primary infxn –> Gingiovostomatis/GINGIVAL ULCERS, Keratoconjunctivitis (cornea-itis and conjunctivitis), Temporal Lobe encephalitis*, Herpes Labialis (grouped, confluent vesciles, erythematous rim)
- Reactivation –> Cold Sores
- latent in TRIGEMINAL ganglia (mostly affects the mouth, eyes, lips, temples!…orallobe)
- Kids w gingival ulcers, cervical lymphadenopathy, swollen gums**
VZV (HHV-3)
ds DNA, linear, enveloped
- spread by respiratory secretions
- -> Chicken pox (rash on trunk –> periphery) and shingles, encephalitis, pneumonia
- Latent in DORSAL ROOT or TRIGEMINAL ganglia
CMV (HHV-5)
dsDNA, linear, enveloped
- spread: congenital, transfusion, sex, saliva, urine, transplant
- ->Congenital, “MONO” (neg monspot)
- Reactivation –> pneumonia, retinits (in AIDS, cotton-wool spots)*
- “owl eye” inclusions
- Latent in MONONUCLEAR cells
- binds to CELLULAR INTEGRINS
EBV (HHV-4)
dsDNA, linear, enveloped
- spread by respiratory, saliva
- ->Mono, Burkitt’s/Hodgkins, Nasopharyngeal Carcinoma
- latent in B cells (in 90% of us)
- Reactivation in Immunosuppresed(HIV**) –> NHL/DLBCL/Burkitts
Roseola (HHV-6)
dsDNA, linear, enveloped
–>Roseola: high fevers for days (can cause seizure) –> diffuse macular rash on trunk –> periphery
HSV indentification
- PCR (gold standard)
- TZANCK test: smear opened skin vesicle (HSV1/2/3). Look for multinucleated giant cells w intranuclear inclusions
- Infected cells: COWDRY A INCLUSIONS
- Cutaneous HSV: grouped vesicles on an erythematous base.
HHV-8
dsDNA, linear, enveloped
- -> Kaposi’s sarcoma in HIV pts
- spready by Sex
EBV –> MONO
- sxs: fever, hepatosplenomegaly, pharyngitis, lymphadenopathy post cervical**
- 15-20 yrs
- infects B cells (CD21)
- atypical lymphs on periph smear: CD8+
- Pos. monospot test: Heterophile ab’s –> agglutinate sheet/horse rbcs
