Test 2: Dx, Tx, and Prevention Flashcards
What does PCR stand for?
Polymerase Chain Reaction
What is PCR used for?
PCR is used to make
multiple copies of a segment of DNA
What is it called when you take one segment of DNA and make multiple copies of it?
Amplification
The following steps describe this process of diagnosing viral infections:
- Amplify DNA
- Subject DNA to electrophoresis in agarose gels
- Stain with ethidium bromide
PCR
In PCR, what temperature is used to denature (or separate) the strands of DNA?
94 - 96C
In PCR, what temperature is used to **anneal **the primers to the ends of both strands of denatured DNA
68C
for annealing
T/F:
In the annealing step of PCR,
the forward primer (+) binds to the forward DNA strand (+)
FALSE!!!
the forward primer (+)
binds to the
reverse DNA strand (-)
In PCR, what temperature is used to
elongate each strand of DNA after they have been annealed to their primers?
72C
The **elongation **step in PCR uses
______ polymerase to create a new DNA segment that is
complementary to the original DNA strand
TAQ polymerase
What is the result of the **elongation **step of PCR?
2 new DNA molecules
each with
1 **NEW **strand
and
1 OLD strand
Repeating the process of PCR for 30 - 40 cycles
yields how many exact copies of the original DNA segment?
1 billion!!!
While PCR is used to make multiple copies of DNA,
what is QPCR used for?
Quantitative PCR
is used for the
- monitoring and quantification*
- of PCR products and nucleic acid load*
Why is QPCR useful?
QPCR is used to monitor the
viral load in a patient
What 3 target-specific probes are used in the **QPCR **process?
- 5’ TaqMan probe
- Molecular Beacon probe
- FRET hybridization probe
“Taqman frets when he can’t find bacon, so he probes for it!”
Intercalating dyes, like SYBR green are used in what diagnosis technique?
QPCR
What is a flurophore?
(SYBR green for example)
Flurophore is a probe or a dye that emits fluorescence
What is the most widely used method of
Genome Sequencing?
Sanger Dideoxy Method
What does NGS stand for?
New Generation Sequencing
Illumina (Solexa) sequencing is an example of this type of genome sequencing
NGS
new generation sequencing
Which method of genome sequencing is
cheaper
quicker
more accurate and reliable
and
Needs LESS DNA?
Illumina (Solexa) new generation sequencing
The study of microbial populations in a sample by
analyzing the sample’s entire nucleotide sequence
is called?
Metagenomics
What is metagenomics used for?
The random detection of existing and new pathogens
NGS platforms are being used for the formation of
___________ databases
metagenomics
Genome sequencing is crucial in
_______ studies for pathogen detection using metagenomics
surveillance
The use of virus genome sequence data to study
evolution and genetic relationships of viruses
is called
phylogenetic analysis
Phylogenetic analysis has been used to related
porcine rotavirus to human rotavirus.
Which lineage is the porcine one and which is the human one?
Lineage 1 is porcine (RU172/G12)
Lineage 2 is human (RVA/G12)
both are related to the VP7/G12 genotype
T/F:
QPCR is the same thing as RTPCR
TRUE!
Quantitative PCR is the same as Real Time PCR
Which process of viral detection can screen hundreds of pathogens simultaneously and uses only 1 silicon chip?
Microarrays
In a microarray
**probe DNA **and sample DNA interaction
is called
hybridization
What does a positive reaction in a microarray test for pathogens look like?
Fluorescence on the chip where the probe was
is indicative of a (+) reaction
What are the 4 ways of treating viral diseases?
- Antivirals
- Immune system stimulation
- Antibody synthesis
- Antibody administration (natural antiserum)
This class of proteins with antiviral effects is used to stimulate the immune system in the treatment of viral diseases
interferons
T/F:
You can use an antibiotic to treat a viral infection
FALSE!!
Antibiotics should be known as “antibacterials” because they only treat BACTERIAL infections
Compared to antibiotics, only a few antivirals are effective. Why is this?
Agents that kill viruses will also kill the host cell
(because viruses depend on the host cell for replication)
Antiviral chemotherapeutics are NOT common in vet med. Why not?
The cost is too high
It’s hard to find effective ones that are not cytotoxic
There are no rapid diagnosis tests so acute-onset viral infections cannot use them anyway
What are the 6 steps in the Virus life cycle?
- Receptor binding
- Cell entry
- Uncoating
- Nucleic acid synthesis
- Assembly
- Release
What are **receptor analogs (antiviral drug) **used to target?
Receptor analogs target
*attachment *of the virion to the cell receptor
What Rimantadine (antiviral drug) used to target?
Rimantidine targets
uncoating
What are transcriptase inhibitors (antiviral drug) used to target?
Transcriptase inhibitors target
primary transcription from viral genome
What antiviral drug targets
reverse transcription?
Zidovudine (AZT)
targets viral reverse transcription
**Lentivirus TAT inhibitors **are antiviral drugs used to target what?
Lentiviral TAT inhibitors
target
regulation of transcription
What is Ribavirin (antiviral drug) used to target?
Ribavirin
targets the
processing of RNA transcripts
Interferons, when used as antiviral drugs, target
translation of viral RNA into proteins
is the target of Interferons