Gastro-Adeno-Papilloma (EXAM IV)

Question 1

-inflammation of stomach or intestines
-important disease of infants and children
-leading cause of childhood death in developing countries

Answer 1

Viral gastroenteritis

Question 2

The naming of viral gastroenteritis is named base on:

Answer 2

Tissue tropism; not viral structure

Question 3

Viral gastroenteritis is an important disease of ____ & ____

Answer 3

Infants & children

Question 4

The leading cause of childhood death in developing countries:

Answer 4

Viral gastroenteritis

Question 5

Viral gastroenteritis causes inflammation of:

Answer 5

Intestines & stomach

Question 6

Etiological agents of viral gastroenteritis in humans include: (6)

Answer 6

1. Rotavirus (groups A, B, C)
2. Norovirus
3. Sapovirus
4. Enteric adenovirus
5. Astrovirus
6. Aichi virus

Question 7

Describe the genomic structure of groups A, B & C rotaviruses:

Answer 7

Segmented double stranded RNA

Question 8

Describe the genomic structure of Norovirus, Sapovirus, Astrovirus, & Aichi virus:

Answer 8

+ Sense single stranded RNA

Question 9

Describe the genomic structure of enteric adenovirus:

Answer 9

Linear double stranded DNA

Question 10

A major cause of diarrhea in children 6-24 months:

Answer 10

Group A rotavirus

Question 11

A major cause of diarrhea outbreaks in children & adults:

Answer 11

Norovirus

Question 12

~50% of diarrhea cases still have:

Answer 12

Unknown etiology

(meaning we likely still have yet to discover many pathogens)

Question 13

First virus identified from stool samples by electron microscopic examination in 1972:

Answer 13

Norwalk virus

Question 14

What family of viruses are rotaviruses members of?

Answer 14

Reovirus family

Question 15

What does reovirus stand for?

Answer 15

Respiratory Enteric Orphan viruses

Question 16

Describe the characteristic structure of Rotaviruses:

Answer 16

-nonenveloped
-inner & outer capsule

Question 17

How do rotaviruses enter most cells?

Answer 17

Endocytosis

Question 18

What happens once the rotavirus has been endocytosed into the host cell?

Answer 18

Exit the phagosome

Question 19

What allows for the DS-RNA genome of the rotavirus to be copied once inside host cell?

Answer 19

They use an RNA-dependent RNA polymerase

(part of viral structure)

Question 20

What does the viral protein produced by the mRNA of rotavirus assemble into?

Answer 20

Capsid structures

Question 21

Where does the viral replication of rotavirus complete?

Answer 21

Inside capsid structures

Question 22

How does rotavirus acquire an envelope?

(Recall: originally this virus is unenveloped upon entering host cell)

Answer 22

By budding into endoplasmic reticulum

Question 23

Following acquiring its viral envelope from the ER, when does rotavirus shed its envelope:

Answer 23

Sheds envelope as the second capsid layer is build & the virus is released

Question 24

What does the release of rotavirus involve?

Answer 24

Lysis of infected cell

Question 25

What is responsible for the tissue damage associated with rotavirus?

Answer 25

Lysis of infected cells (virus release)

Question 26

What is responsible for fatality of infection by rotaviruses?

Answer 26

Dehydration

Question 27

Discuss the transmission of rotavirus:

Answer 27

Fecal-oral

Question 28

What is responsible for the acid-stability seen in rotavirus?

Answer 28

Double capsid structure

Question 29

During active infection of rotavirus how many particles can be shed per ml of stool?

Answer 29

10^12 viral particles

Question 30

How many viral particles are necessary to initiate infection with rotavirus?

Answer 30

As few as 10

Question 31

What is the characteristic symptom of infection with rotavirus?

Answer 31

Watery-diarrhea

Question 32

Rotaviruses produces a ______

Answer 32

Enterotoxin

Question 33

The enterotoxin produced by rotavirus binds _____ resulting in ____

Answer 33

Integrins; signaling that causes secretion of chloride & water

Question 34

The enterotoxin produced by rotavirus ultimately results in:

Answer 34

Secretion of chloride & water

Question 35

During rotavirus infection, what happens to infected gut epithelial cells?

Answer 35

These cells are destroyed & replaced by immature epithelial cells

Question 36

During a rotavirus infection, what is the significance of the infected gut epithelial cells being replace with immature epithelial cells?

Answer 36

1. Reduced uptake of ions
2. Reduced water uptake
3. Less absorption of food molecules (carbs)

Question 37

Most common type of rotavirus in the United States:

Answer 37

Group A

Question 38

Is there a vaccine for rotavirus?

Answer 38

Yes- for infants & greater than 75% effective

Question 39

Describe the genomic structure of Noroviruses:

Answer 39

• positive single stranded RNA genome
• around 7500 bases in length
• naked capsule virions

Question 40

Describe the virions of noroviruses:

Answer 40

Naked capsid viruses

Question 41

The replication of noroviruses are similar to ______

Where do they differ?

Answer 41

Picornaviruses (poliovirus); differ in the second phase of translation

Question 42

How does the second phase of translation of noroviruses differ from the replication of picornaviruses (poliovirus)?

Answer 42

The second phase of translation involves subgenomic RNAs

Question 43

The second phase of translation of noroviruses involve subgenomic RNAs being produce, what other virus is this similar to?

Answer 43

Coronaviruses

Question 44

Similar to picornaviruses, noroviruses have a _____ on the RNA

Answer 44

5’ VPg protein

Question 45

Because the norovirus is a naked capsid virus, infection will result in:

Answer 45

Tissue damage

Question 46

Virus that is characteristically a causative agent of infection in big group, confined setting such as cruise ships:

Answer 46

Norovirus