C6 Flashcards
1
Q
Application of molecular detection
A
- Bacteria
- Virus
- Fungi
2
Q
Explain respiratory tract pathogens
A
- Easily transmitted by contact with infected person
- Lab detection lack sensitivity & time consuming
3
Q
Explain M.tuberculosis
A
- Diagnosis took long time (spread the disease)
- Diagnose by mycobacteria smear & culture
4
Q
Example of MTB methods
A
- Amplified M.tuberculosis Direct Test
- AMPLICOR M.tuberculosis PCR Test
5
Q
Explain amplified M.tuberculosis direct test
A
- Use transcription mediated amplification to amplify 16S rRNA
- Amplified rRNA detect using same DNA probe in DNA probe assay & measure chemiluminescence of rRNA - DNA
- Performed in 3.5 hours in single tube with 100% specificity
6
Q
Explain AMPLICOR MTB Test
A
- Use to detect M,tuberculosis directly
- Cell are lyse in the sample releasing mycobacteria DNA
- DNA denature & primer complementary to 584 bp region of 16S rRNA
- DNA polymerase make copy of target DNA
- Product detection using DNA probe specific
7
Q
Time and sensitivity of Amplified & AMPLICOR
A
Ampified
- 3.5 hours
- Positive: 100%
- Negative: 83%
AMPLICOR
- 6.5-8 hours
- Positive: 94.7%
- Negative: 55.3%
8
Q
Explain detection of virus
A
- Detect by testing antibodies, measure presence or absence of viral antigen, detect growth
- Viral antigen detect by enzyme immunoassay or direct immunofluorescent assay
9
Q
Explain molecular diagnostic in virus
A
- Use PCR, RTPCR, qPCR, TMA & bDNA to diagnose viral infections
- HIV, HCV & HPV use molecular based test
10
Q
Example of nucleic acid test for virus
A
- HIV: PCR, RT-PCR, bDNA
- HPV: PCR, qPCR
- Corona & Influenza: RT-PCR
11
Q
Test performance features for viral load measurements
A
- Sensitivity: lowest level detect at 95% of the time
- Accuracy: closeness measure value to standard
- Specificity: negative & positive result true
12
Q
Detection of resistance & virulence
A
- Microbe develop defence to antimicrobial agent
- Resistant arise from alerted target binding, active extrusion
- Single nucleotide variant in drug target or transport result in resistance
13
Q
Mechanism of resistance
A
- Destruction of agent: Beta lactamase
- Elimination of agent: Multidrug efflux system
- Alter cell wall structure
14
Q
4 reason for using molecular based method to detect resistance
A
- Potential effectiveness of agent
- Gene involve in resistance can be detected directly
- Monitoring spread of resistance gene
- Gold standard for validation of new phenotypic assay
15
Q
Explain molecular epidemiology
A
- Epidemiology include collection & analysis of env, microbiological & clinical data
- Study of causative genetic & environmental factors at molecular level
- Diseases: determine genetic similarities & differences among microbiological isolate
- Lab: identify & typing infectious agents
16
Q
Epidemiology typing methods
A
Phenotypic
- Serotyping
- Biotyping
Genotypic
- Ribotyping
- Plasmid analysis
