ANTIMICROBIAL CHEMOTHERAPY Flashcards
1
Q
What are the four main causes of death (disease ONLY)?
A
- AIDS: viral infection
- TB: bacterial infection
- Malaria: protozoal infection
- Cancer: uncontrolled cell proliferation
2
Q
What is the aim of selective toxicity and explain how this affects treating microbes?
A
- Selective Toxicity - toxic to microbe but not to the host cell
- Bacteria - different cell structures from humans (cell walls) = easy to treat
- Protozoa are eukaryotic = similar cell structures = hard to treat
- Virus hijack cells = and become similar to humans = hardest to treat (and cancers too)
3
Q
What the causative agent of Syphilis?
A
Treponema pallidum (spirochaete bacterium)
4
Q
What happens when Syphilis is left untreated?
A
Damages brain, heart and nervous system and is eventually fatal
5
Q
What was the FIRST treatment for Syphilis and who created it?
A
- Salvarsan (modification of Atoxyl - which cause blindness)
- Paul Ehrlich
- Salvarsan was supposed to cure trypanosomiasis (sleeping sickness)
6
Q
What was the mechanism of action of Salvarsan?
A
- Salvarsan (prodrug) → oxophenarsine (oxidised slowly)
- Oxophenarsine reacts with thiol (R-S-H) groups in proteins, causing denaturation.
- thiol containing amino acids = methionine and cysteine
7
Q
Why was neosalvarsan used instead of salvarsan in the treatment of syphilis?
A
- Neosalvarsan is more water soluble and less toxic than salvarsan (but was replaced by penicillin)
8
Q
What’s the structure of Neosalvarsan (neoarsphenamine)?
A
9
Q
What did Ehrlich contribute to modern chemotherapy? (3)
A
- Screening techniques: he applied simple tests to large number of compounds
- Structure activity relationships: synthesis of chemical variants of an active compound to try to improve activity.
- Prodrugs
10
Q
What drug is used to treat MRSA and multi-resistant strep pneumoniae?
A
Vancomycin
