Gastro-Adeno-Papilloma- Exam IV Flashcards
- inflammation of stomach or intestines
- important disease of infants and children
- leading cause of childhood death in developing countries
viral gastroenteritis
The naming of viral gastroenteritis is named based on:
tissue tropism; not viral structure
viral gastroenteritis is an important disease of ___ & ___
infants and children
The leading cause of childhood death in developing countries:
viral gastroenteritis
Etiological agents of viral gastroenteritis in humans include: (6)
- rotavirus (Groups A,B & C)
- Norovirus
- Sapovirus
- Enteric adenovirus
- Astrovirus
- Aichi virus
Describe the genomic structure of groups A, B, and C rotaviruses:
segmented double stranded RNA
Describe the genomic structures of Norovirus, Sapovirus, Astrovirus and Aichi virus:
positive sense single stranded RNA
Describe the genomic structure of enteric adenovirus:
linear double stranded DNA
Major cause of diarrhea in children 6-24 months:
Group A rotavirus
Major cause of diarrhea outbreaks in children and adults:
Norovirus
~50% of diarrhea cases still have:
unknown etiology (meaning we likely still have yet to discover many pathogens)
first virus identified from stool samples by electron microscopic examination in 1972:
Norwalk
What family of viruses does Rotaviruses belong too?
Reovirus family
What does Reovirus stand for:
Respiratory Enteric Orphan virus
Describe the characteristic structure of rotaviruses:
- nonenveloped
- inner and outer capsids
How do rotaviruses enter host cells?
endocytosis
What happens once rotaviruses have been endocytosed into the host cell?
exit the phagosome
What allows for the ds-RNA genome of the rotavirus to be copied inside the host cell?
RNA dependent RNA polymerase
What does the viral protein produced by the mRNA of rotavirus assemble into?
capsid structures
Where does the viral replication of rotavirus complete?
inside capsid structures
How rotavirus acquire an envelope? (recall it is originally unenveloped upon entering host cell)
by budding into ER
Following acquiring the viral envelope via the ER, when does rotavirus shed the envelope?
Sheds envelope as the second capsid layer is build and the virus is released
What does the release of the rotavirus envelope involve?
Lysis of infected cells
What is responsible for the tissue damage associated with Rotaviruses?
lysis of infected cells
What is responsible for the fatality of infection rotaviruses?
dehydration
Discuss the transmission mode of rotavirus?
fecal-oral transmission
What is responsible for the acid stability seen in rotavirus?
double capsid structure
During an active infection of rotavirus, how many particles can be shed per ml of stool?
10^12 viral particles
How many viral particles are necessary to initiate infection of rotavirus?
as few as 10
What is the characteristic symptoms of infection with rotavirus?
watery-diarrhea
Rotavirus produces a ___.
enterotoxin
The enterotoxin produced by rotavirus binds ____, resulting in ___.
integrins, signaling that causes secretion of chloride and water
The enterotoxin produced by rotavirus ultimately results in:
secretion of chloride and water
During rotavirus infection, what happens to infected gut epithelial cells?
these cells are destroyed and replaced by immature epithelial cells
During a rotavirus infection, what is the significance of the infected gut epithelial cells being replaced with immature epithelial cells:
- reduced uptake of ions
- reduced water uptake
- less absorption of food molecules (carbs)
What is the most common type of rotavirus in the U.S?
Group A
Is there a vaccine for rotavirus?
Yes- for infants and greater than 75% effective
Describe the genomic structure of Noroviruses:
- positive single stranded RNA genome
- ~7,500 bases in lengths
~ Naked Capside virions
Describe the virions produced by Noroviruses:
naked capside virions
The replication of Noroviruses are similar to ____ except for ____.
picornavirus (polioviruses); except for 2nd phase of translation
How does the 2nd phase of translation of Noroviruses differ from the replication of picornaviruses (poliovirus)?
The second phase of translation involves subgenomic RNAs
The second phase of translation of noroviruses involve subgenomic RNAs being produce. What other virus is this similar to?
coronaviruses
Similar to picornaviruses, Noroviruses have a ____ on the RNA.
5’ VPg protein
Since the Noroviruses is a naked capsid virus, infection will result in:
tissue damage
Virus that is a characteristically a positive agent of infection in big group confined settings such as cruise ships:
Noroviruses