Picornavirus Flashcards
enterovirus: acid stable or labile?
stable
describe antigenic neutralizing sites on poliovirus type 1
viral binding site is a canyon that surrounds the 5-fold axis; antigenic neutralizing sites surround the canyon; hydrophobic pocket at the base of the canyon
how the polio vaccine works
the antibody binds to the canyon of the virus and blocks the cell receptor from binding to the virus
polio virus receptor
PVR
coxsackieviruses group B receptors
hCAR, DAF
major human rhinovirus receptor
ICAM-1
organization of the picornavirus RNA genome
positive sense RNA, single stranded, 5’ NTR, poly A tail, protein coding region, 3’ NTR
the protein coding region for picornavirus genome
P1: viral capsid coding region
P2/P3: nonstructural protein coding region
the 5’ NTR of the enteroviruses comprises what percent of their genome?
10%
what causes attenuation of the polio virus?
single nucleotide change that causes a loop in the translation protein
the polio virus makes 2Apro protein in order to inhibit..
the eIF-4G complex that helps initiate translation
the polio virus makes 3Cpro protein in order to inhibit..
PABP from binding to the polyA tail
the poliovirus inhibits the host cell’s machinery in order to..
only make copies of itself, not the host’s proteins
transmission of enterovirus
fecal-oral, respiratory, shedding, incubation period is variable
modes of vertical transmission of enterovirus/what this causes in the newborn
congenital (transplacental), peripartum; cause neonatal sepsis
a congenital condition which would cause susceptibility to contracting enterovirus from the mother during 3rd trimester or during birth
x-linked agammaglobulinemia (B cell deficiency)
enterovirus elimination by the body involves..
humoral (B cell) immunity, not T cells
vaccine strains of poliovirus are called.
Sabin strains
*primary sites of distribution of lesions due to poliomyelitis
grey matter anterior horns of spinal cord//motor nuclei of pons and medulla (affects motor and autonomic neurons)
most common clinical presentation of polio
minor illness (90-95%)
abortive poliomyelitis symptoms
fever, headache, stiffness of neck, back hamstrings, hyperesthesias, paresthesias
CSF changes are consistent with aseptic meningitis in
abortive poliomyelitis
how can you differentiate paralytic poliomyelitis from Guillian-Barre syndrome?
paralysis is ASYMMETRIC and flaccid in polio, SYMMETRIC in Guillain-Barre syndrome
*describe Sabin vaccines for polio
live attenuated, induces systemic AND gut immunity to polio
entervirus is responsible for more than 85% of cases of..
aseptic meningitis in the US
which produces more neurologic findings: encephalitis or meningitis?
encephalitis since its infection of the brain itself
enterovirus that’s responsible for most acute sporadic myocarditis
group B coxsackievirus
what enterovirus causes hand foot and mouth disease?
coxsackie virus A-16
where you would find vesicles in a patient with herpangina (from coxsackievirus)
tonsils, uvula, tongue, palate, posterior pharynx, anterior pillars of the fauces
what enterovirus causes pleurodynia (epidemic myalgia, Bornholm disease)?
coxsackievirus group B (devil’s grip chest pain)
*most severe form of sepsis for babies
neonatal enterovirus sepsis syndrome
neonatal enterovirus sepsis syndrome causes..
hepatitis, myocarditis, meningo-encephalitis
*clinical findings of children with chronic enteroviral meningoencephalitis in agammaglobulinemia (CEMA)
Chronic meningitis
dementia
hepatitis
dermatomyositis
rituximab targets..
CD20 (anti-B cell)
*cell culture for detection of enterovirus has been replaced by..
RT-PCR (rapid diagnosis test of choice)
