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Flashcards in Supplementary Lectures Deck (22)
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1
Q

what is genomic drift

A

where the haemagglutinin of the virus changes slightly but is still recognisable

2
Q

What are the steps of a haemagglutination inhibition assay

A
  1. Virus binds to RBCs 2. Specific antibodies prevent shield forming 3. Virus cannot cross link with RBC when antibody bound 4. RBC fall to the bottom of the well- button
3
Q

What are the steps of a haemagglutination assay

A
  1. Virus binds to RBCs 2. Cells fall to the bottom of the wells due to gravity 3. Sialic acids bound to by virus, forming a shield at the well bottom 4. Perform serial dilution 5. The last well with a shield means you can calculate the virus titre
4
Q

Explain the stages of viral replication

A
  1. virus adheres to cell surface 2. virus enters cell by pinocytosis 3. virus sheds coat 4. replication of viral nucleic acids 5. synthesis of viral protein of capsid 6. assembly of new virions 7. release of virus
5
Q

What is a plaque assay

A

used to purify a clonal population of virus or to determine viral titer

6
Q

What is the end-point of the assay

A

1/512

7
Q

What is would a positive result of a haemagglutination inhibition assay show

A

button

8
Q

What is the baltimore classification system

A

How viruses nucleic acids make mRNA

9
Q

Would genomic drift or shift be more likely to cause a pandemic

A

Shift

10
Q

What can viruses be classified based on

A

• Size, shape (helical, icosahedral, complex) • Type of nucleic acid in the genome (No strands/Sense) • How they produce mRNA

11
Q

What strain of influenza is Patient ‘JB’ was infected by

A

H1 strain of influenza

12
Q

What does neuraminidase facilitate

A

the release of the virus from infected host cells

13
Q

What do viruses contain

A

• A Nucleic acid – RNA or DNA • Viral proteins on their surface • Nucleocapsid- forms shape • Lipid envelope- usually originates from host cell

14
Q

True or false: Viruses are visible under a light microscope

A

False

15
Q

Why can sense RNA viruses not act as an RNA template

A

risk of mutation

16
Q

What is genomic shift

A

when the haemagglutinin of the virus changes completely

17
Q

Explain the steps of a plaque assay

A

10-fold dilutions of a virus stock are prepared, and 0.1 ml aliquots are inoculated onto susceptible cell monolayers. Monolayers are covered with a nutrient medium containing agar original infected cells release viral progeny. each infectious particle produces a circular zone of infected cells called a plaque. Eventually the plaque becomes large enough to be visible to the naked eye.

18
Q

How many groups are there in the baltimore classification system

A

7

19
Q

What can be used to subtype viruses

A

neuraminidases

20
Q

what is qt-PCR

A

the RNA in the virus is converted to CDNA which then gets amplified. It monitors the amplification in real-time

21
Q

What does haemagglutinin facilitate?

A

entry of the virus into host cells (binds to sialic acid)

22
Q

What is would a positive result of a haemagglutination assay show

A

a shield