Anti-Microbial drugs Flashcards
1
Q
What are microbes?
A
- Fungi
- Protista
- Bacteria
2
Q
What are some common anti-microbials?
A
- Silver
- UV light
- Strong radiation
3
Q
What is penicillin?
A
- Binds proteins which can break down/stop production of peptidoglycans
- Beta-lactam ring binds
- Bacteria have learnt to produce an enzyme that cleaves the antibiotic
1. Beta-lactamases–> Break beta-lactam ring first
4
Q
What is crystallography?
A
- Make a crystal from the molecule, then scatter x-rays from the crystal which get diffracted.
- Can calculate what molecule looks like from scattered/diffracted pattern
5
Q
Why/how are ribosomes targeted?
A
- Targeted by many antibacterials
- Many binding sites on both sub-units
- Tetracyclin binds to both RNA and protein sites
6
Q
What are Quinolones?
A
E.g. Ciproflaxacin
- DNA gyrase (topoisomerase II) and Topoisomerase IV inhibitors
- Broad spectrum of activity
- Some slectivity for bacterial topoisomerase
(Drugs that target DNA transcription and replication processes)
7
Q
How is drug resistance mediated?
A
- By several mechanisms
- Inc Ribosomes changing binding site so that drugs can no longer bind (2nd defence mechansim)
- (midifying enzymes?)
- Can develop protein that protects binding ste for particular dugs (competitor protein) (3rd defence mechanism)
- Efflux pumps -(4th defence mechanism)
8
Q
What are Quorum-sensing pathways?
A
- Signals sent between bacteria that let them clump together
- Form biofilm for better protection/survival
- ^–Possible target for anti-microbial treatment
9
Q
What are pore-forming peptides?
A
- Bind to membrane and make holes in them
- Potential use for anti-microbial treatment
10
Q
What are Bacteriophages?
A
- Viruses that parasitizes a bacterium by infecting it and reproducing inside it
- Can be used as anti-microbial (soviets WW2)
- Superseeded by penicillin etc
- Interest because of emergence of MRSA
11
Q
What is the summary of Anti-microbial targets?
A
Anti-microbials target processes that are essential and specific for life of microrganism
- Cell wall formation
- Protein synthesis
- DNA transcription and translation
12
Q
What is the summary of resistance mechanisms that have evolved?
(for the cell)
A
- Enzymatic modification of drug
- Limiting uptake of the drug
- Pumping drug out
- Modifying target- either by mutagenesis or special protective proteins
13
Q
What is the summary of alternative treatment strategies?
A
- Quorum sensing pathways
- Pore-forming peptides
- Bacteriophages
