virology

Question 1

difference of bacteria infection and all cells infected rate

Answer 1

Bacteria spread in a steady rate

while other spread in a burst rate

Question 2

definition of a virus

Answer 2

infectious, obligate intracellular parasite containing genetic material

so if it don’t have a nucleic acid, its not virus

Question 3

what particles that forms into a virus

Answer 3

genome (RNA/DNA)

Capsid

envelop

Question 4

what type of cell do virus infect?

Answer 4

they have the ability to infect all type, but they have preferences

Question 5

what is a basic virus structure consist of?

Answer 5

• nucleic acid
• capsid
• glycoprotein
• matrix protein
• envelope

Question 6

what are the virus replication cycle

Answer 6

• attachment
• prenetration
• uncoating
• biosynthesis
• assembly
• release

Question 7

what are the 3 internalisations stage?

Answer 7

• fusion –> they uncoated at the cellular external plasma membrane and allow the viral genetic material to go into the cytoplasm
• endocytosis –> the whole virus goes in surrounded by endosomes and uncoating within the cytoplasm
• intensive trafficking –> where the whole virus goes in through the endosome and releases viral RNA at the nuclear membrane

Question 8

how many groups are in the Baltimore classification

Answer 8

7

Question 9

what are the group in the Baltimore classification

Answer 9

group 1 - Double-stranded DNA
group 2 - Single-stranded DNA
group 3 - Double-stranded RNA
group 4 - Single-stranded RNA (+)
group 5 - Single-stranded RNA ( - )
group 6 - single-stranded RNA viruses with reverse transcriptase
group 7 - Double-stranded DNA viruses with reverse transcriptase

Question 10

why viral genomes are the fastest evolving entities in biology?

Answer 10

• short replication time
• large numbers of progeny released per cell infected
• virus genomes display a higher mutation rate than cellular organisms
• their polymerases typically have a higher mutation rate than cellular polymerases
• High mutation rate often produces more deficient than infectious genomes
• rapid evolution through natural selection

Question 11

what are the viral exit currently have for virsus

Answer 11

Budding-enveloped viruses take some cell membrane on their way out

cell lysis - viruses burst out of the cell

triggering apoptosis

exocytosis

Question 12

how do viruses damage host cells

Answer 12

lysis

multinucleated syncytium (where cells are cluster up together)

transformation

Question 13

What is a cytopathic effect (CPE)

Answer 13

Structural changes in the host cell because of viral infection

Question 14

when will CPE occurs

Answer 14

when the cells dies without lysis because of its ability to reproduce

Question 15

what kind of transmission can we get infected?

Answer 15

abrasion
respiratory tract
gastrointestinal tract
Conjunctiva (loose connective tissue that covers the surface of the eyeball)
genital tract

Question 16

what is a viraemia

Answer 16

a medical condition where viruses enter the blood stream and be able to access to the rest of the body

Question 17

example of viraemia

Answer 17

viraemia in plasma - polio

persistent viraemia

• Epstein Barr virus (EBV) in B-lymphocytes
• Huma immunodeficiency virus (HIV) in T-lymphocytes

Question 18

what are the features in the acute infection

Answer 18

• recover by eliminating the virus

- recovery is followed by partial or complete immunity

Question 19

examples of acute infection

Answer 19

• rhinovirus
• rotavirus
• influenza virus

Question 20

features in persistent infection

Answer 20

evasion of the immune system
the ability of immunosuppression –> cause disease
latent so it can stay in the body for a long time
^ must be able to receive e.g. stress/trauma

Question 21

what requirement does virus need to be able to spread in the host

Answer 21

• invade the host
• establish a local stronghold
• overcome local defences
• be able to spread from the site of entry to other areas
• be able to replicate in local area
• have a exit pathway to go and affect other area

Question 22

why there is fewer antiviral drugs than antibiotics?

Answer 22

the drug used in targeting viruses tended to attack normal host cells as well

selective toxicity - harder to find a point of attack when constantly used

lack of rapid diagnostics

no broad-spectrum antivirals

viruses replicate intracellular, so drug need to penetrate cell to inhibit here

they must be very effective to prevent for resistance

Question 23

where is the good way to inhibit viral infections?

Answer 23

inhibit the nucleic acid synthesis

protease inhibitors

inhibit penetration

immunomodulators

Question 24

what is varicella zoster virus (VZV)

Answer 24

primary infection that causes chicken pox

Question 25

what is MMR

Answer 25

Measles-mumps-rubella

Question 26

what is the general principles of the spread of the virus?

Answer 26

horizontal spread - e.g. air, water, food, contact

vertical spread - e.g. sexual contact, contaminated breast feeding