Rna Viruses Ii:

Front 1

What are the different viruses covered in this lecture?

Back 1

1.) positive RNA: picornaviridae (non-enveloped and icosahedral)
2.) positive RNA: coronaviridae (helical and enveloped)
3.) positive RNA (non enveloped and icosahedral: caliciviriadae
4.) double stranded; non-enveloped: icosahedral: reoviridae

Front 2

Why is there no need to make mRNA: for the positive sense RNA viruses?

Back 2

positive sense RNA genomes can go directly to proteins

Front 3

positive stranded RNA viruses: 4 general important points:

Back 3

1.) genome serves as mRNA and is infectious
2.) they are all non-segmented (note that the reovirus ds dna is segmented)
3.) virions do NOT contain any enzymes
4.) structure: enveloped or naked/ icosahedral or helical

Front 4

What are the two main groups of picornaviruses and the subgroups of each of these groups?

Back 4

1.) rhinoviruses (103 serotypes)

2.) enteroviruses:
PECU:
poliovirus, echovirus, coxsackie viruses A and B, unknown enteroviruses

Front 5

Describe the viral entry and receptor specificity for the picornaviruses? What are the surface cell receptors, in particular, that enterovirus binds to. (Hint: it is different for poliovirus vs. coxsackie virus and rhinovirus)

Back 5

-coxsackie virus and most rhinoviruses bind to ICAM-1
-poliovirus: binds to cell surface glycoprotein called CD155 (the poliovirus receptor)

Front 6

What are four key points for enteroviruses?

Back 6

1.) major portal of entry is the mouth via ingestion of contaminated food or water; transmitted by the fecal-oral route
2.) stable at a low pH of the stomach; replicate in the GI tract and excreted in the stool
3.) stable at room temperature
4.) immunity is type-specific

Front 7

Describe the pathogenesis of the enterovirus infection: The target tissue infected by the enterovirus determines the predominant disease caused by the virus.

Back 7

SKIN, MUSCLE, BRAIN, MENINGES:
enterovirus --> viral replication in oropharynx and intestine --> viral replication in lymphoid tissues --> viremia:
SKIN: coxsackie virus A: hand food and mouth disease and herpangia
MUSCLE: echovirus: coxsackieviruses A and B: --> Heart (myocarditis) and thorax (pleurodynia)

BRAIN: poliovirus, coxsackieviruses A and B --> Paralytic disease and encephalitis

MENINGES: echovirus, poliovirus, coxsackieviruses A and B --> meningitis

Front 8

What are these pictures of?

Back 8

coxsackie A hand foot and mouth disease

Front 9

What are these pictures of?

Back 9

herpangina; coxsackie A

Front 10

Describe pathogenesis of poliovirus:

Back 10

-major portal of entry is the mouth via ingestion of contaminated food or water; transmitted by the fecal-oral route
-multiples in throat and intestinal tract and enters bloodstream AND spreads to the brain and the spinal cor
-most infections are asymptomatic

Front 11

What virus do these pictures relate to?

Back 11

poliovirus

Front 12

What are the two types of poliovaccines and list pros and cons to each!

Back 12

sabin: induces humoral
-risk of paralytic disease in recipients especially the immunocompromised


Salk:
+induces humoral immunity, no risk of disease in recipients, no shedding of virus, so no risk to contacts, no interference from wild-type non-polio enteroviruses
-: no significant GI immunity and requires booster does AND more expensive

Front 13

CORONAVIRUSES: (5 features)

Back 13

-enveloped and have a helical nucleocapsid
-largest positive strand RNA virus
-second most common cause of the common cold
-club shaped and petal shaped projections on the surface that form a corona or crown around the virus

Front 14

VIRUS STRUCTURE: draw a sample virus structure of a coronavirus how many glycoproteins are there? and list them

Back 14

spike glycoprotein,
hemagluttinin-acetylesterase glycoprotein,
membrane glycoprotein,
small envelope glycoprotein

Front 15

Calciviridae: features:

Back 15

-icosahedral and contain no envelope
-2 genera that contain human viruses: norovirus (norwalk) and sapovirus
-viruses are resistant to environmental pressure, detergents, drying, and acid
-transmission: via fecal-oral route
-common cause of non-bacterial gastroenteritis (major cause of epidemics: 30-40%)

Front 16

REOVIRUSES: What do they stand for and describe them:

Back 16

REO: respiratory, enteric, orphan

-double stranded RNA genome in 10-12 segments;
-nonenveloped with double layered protein capsids each with icosahedral symmetry

-

Front 17

What does reovirus (rotovirus) cause and what are preventative measures?

Back 17

-most common cause of severe dehydrating diarrhea in infants and kids less than 3 years old
-control: consists of rigorous hygienic measures such as careful handwashing and adequate disposal of enteric excretions

Front 18

What is the pathogenesis of the rheovirus:

Back 18