Virology

Question 1

name four ways to classify viruses

Answer 1

1. nucleic acid type
2. capsid type
3. syndrome
4. envelope

Question 2

what are the 5 phases of viral growth

Answer 2

1. attachment
2. penetration
3. uncoating
4. synthetic period
5. maturation and release

Question 3

describe the distinguishing features of DNA viruses

Answer 3

use cellular enzymes for replication

Question 4

describe the distinguishing features of ssRNA

Answer 4

if it is negative sense: first needs to be made as a template for positive sense, to do this it uses RNA dependent RNA polymerase which is from the virus itself
if it is positive sense: it can be translated directly into DNA

Question 5

describe the distinguishing features of dsRNA

Answer 5

replicates in both directions at once, these virus contribute RNA dependent RNA polymerase for the - sense strand to be transcribed into + sense.

Question 6

describe the dis

Answer 6

genome is a ssRNA, uses cells own reverse transcriptase in order to make DNA, this actually incorporate into the hosts genome

Question 7

hepadnaviruses

Answer 7

DNA viruses that cause hepatitis

Question 8

latent viral pathogenesis

Answer 8

acute primary infection, then remains dormant, followed by periods of viral replication during immune compromise. (e.g. HSV)

Question 9

acute viral infection

Answer 9

acute infection (e.g. influenza)

Question 10

slow/persistant viral infection

Answer 10

acute primary infection then period of viral replication at low levels, may be subclinical

Question 11

carrier state

Answer 11

viral rep. present, but not showing symptoms, able to transmit virus to others

Question 12

chronic viral infection

Answer 12

e.g. HIV

Question 13

describe cell death from viral infection

Answer 13

primarily apoptosis, which releases viral products into environment, secondary cell has been hijacked from virus and is only producing viral genome

Question 14

transformation of viral infection

Answer 14

virus takes over host genome to turn on an oncogene and turn off a tumor supressor gene and causes uncontrolled cell growth and division

Question 15

cell fusion of viral infection

Answer 15

causes large multinucleated cells (e.g herpes)

Question 16

cytopathic effect of viral infection

Answer 16

visible changes in a cell that has be affected by a virus

Question 17

Epsetin-Barr virus pathogenesis

Answer 17

acute mononucleosis, part of herpes family, transmitted by oral secretions or blood, affects B cells of oropharynx

Question 18

Epstein-Barr virus Tx

Answer 18

no Tx

Question 19

HSV Tx

Answer 19

acycloir, valycyclovir

Question 20

diagnostic work-up of viruses

Answer 20

PCR, serology (IgM vs IgG), histopathology

Question 21

herpes simplex virus pathogenicity

Answer 21

dsDNA, skin and mucous membranes transmission, is a latent infection