Adenoviruses

Question 1

what is the structure of adenovirus

Answer 1

• icosahedral with capsids
  -contain fibers from each of 12 vertices or penton pases
  -linear dsDNA with GC content

Question 2

what is the function of the penton base and the fibers

Answer 2

• it carries toxin like activity causing rapid appearnce of cytopathic affects and deatachment of cells from the surface
• the fibers contain type specfic antigen for serotyping

Question 3

Adenovirus replication steps?

Answer 3

1- adenoV only replicate in cells with epithelial origin
2- the virus attach via the fiber structure to CAR receptor
3- adsoprtion and internalization into endosomes triggered by acidic pH in endosome
4- uncoating starts in cytoplasm and completes in neucleus

Question 4

Early events of adenovirus replication

Answer 4

• induce cell to enter S phase
  -make E early transcripts

Question 5

function of early protiens

Answer 5

• E1A is expressed for other early regions to be made and modulate cell cycle
  -E1B encodes protien blocking apoptosis because of E1A

Question 6

Pathogensis of adenovirus

Answer 6

it infects the epithelial cells of RT, eye, GIT and UT
- it mostly replicate in intestinal epihtelium after ingestion but produce subclincal infections with exception of serotype 40 and 41.

Question 7

Respiratory disease of Adenovirus

Answer 7

• mostly in infants and children and involve group C virus (1,2,5 for children, 3,4,7 for adults)
• it leads to pneumonia
• it is epidemic in military under stress and fatique

Question 8

Eye infection of adenoV

Answer 8

-Phayngoconjunctival fever specially in summer camps by swimming pool conjuctivits (type 3 and 7).
the duration stays for 1-2 weeks
- Epidemic keratoconjunctivitis by 8, 9 and 37 mainly in adults and leaves subepithelial opacities in cornea for up to 2 years.

Question 9

GI disease of adenovirus

Answer 9

-infantile gastroenteritis by type 40 and 41

Question 10

Labratory diagnosis of adenovirus

Answer 10

1- hemagglutination inhibiton and neutrilzation tests measures type specific antigen
2-shell vial tecnique which is fast
3-cultures incubated for 1 to 2 days
4-PCR assay in respriatory viraldetection panels

Question 11

Serology of adnenovirus

Answer 11

• infection of adneovirus causes rise in complmeent fixing antibodies to andeovirus and it detected by complment fixation test