CMB1003/L10 Treatment of Bacterial Infections Flashcards
Describe late agglutination/ bead equivalent.
Exploiting antibody-antigen interactions for rapid diagnostics
Confirm identity of isolates
Identify known pathogen-associated antigens in specimens when isolation fails
What is serology? (3)
Relies on diagnostic identification of antibodies in the serum
E.g., latex agglutination tests
Only relevant antigens will be bound by specific antibody
What is serotyping? (2)
Determines the subtype of the organism
Allows effective treatment
Give 3 advantages to molecular diagnosis of infections.
Bacterial genomes are unique
Genetic material can be extracted from infected specimens
DNA is easy to detect and quantify
Extremely sensitive 1-10 CFU
Give 3 disadvantages of molecular diagnosis of infections.
Technology is still being developed
Some tests require bacteria to be isolated first
Some tests are too sensitive
Standardisation from lab to lab can be problematic
How can PCR be modified to detect DNA sequences? (2)
Add fluorescent DNA intercalating agent to finished reaction or other fluorescent DNA binding dyes
Add dyes to PCR without inhibiting it and detect PCR product in real-time
Give a successful example of RT-PCR.
Meningitis - pre-emptive treatment before CSF specimen collection
Whooping cough - RT-PCR diagnosis within hours rather than 3-12 days
Give an example of a bactericidal drug.
Penicillin
Give an example of a bacteriostatic drug.
Chloramphenicol
Give 3 antibiotic targets.
Cell wall
DNA/RNA synthesis
Folate synthesis
Cell membrane
Protein synthesis
How can bacteria become resistant to cell wall-targeting antibiotics?
Producing pumps to cause efflux of the antibiotic
How can bacteria become resistant to DNA/RNA synthesis-targeting antibiotics?
Producing inactivating enzymes
Describe the mechanism by which chloroamphenicol, macrolides and lincosamides work. (3)
Bind to 50S ribosomal subunit
Prevent peptide bond formation
Stop protein synthesis
Describe the mechanism by which aminoglycosides work. (2)
Bind to 30S ribosomal subunit
Impair proofreading, resulting in production of faulty proteins
Describe the mechanism by which tetracyclines work. (3)
Bind to 30S ribosomal subunit
Block binding of tRNAs
Inhibit protein synthesis
Define minimum inhibitory concentration (MIC).
The minimum concentration of antibiotic needed to inhibit growth
How can current approaches be modified for treating infections? (3)
Limiting antibiotic use
Last resort antibiotics
Combination therapy
Phage therapy
Faecal transplant
What information is required when an outbreak occurs? (4)
Reported by whom and where
Type of outbreak suspected
Who is affected
Population at risk
Why is global monitoring required? (4)
Health education and protection can limit spread
Monitoring outbreaks can prevent an epidemic
In field diagnostics now available
Transient population and air travel mean no infection barriers
What is Q-POC Platform?
A rapid multiplex PCR testing system that delivers results in approximately 30 minutes at the point of need
What is Q-POC SARS-CoV-2 Assay?
A quality rapid COVID-19 PCR assay that provides results with the simplicity and hands on time of a lateral flow test
