Antimicrobial Chemotherapy Flashcards
1
Q
Decribe Chemotherapy
A
The use of chemicals to inhibit the growth/replication of ‘invading organisms’ or cancerous cells within the body.
2
Q
What make up the bacterial cell wall?
A
Peptidoglycan strands, which are made up of:
- N-acetylglucosamine and N-acetylmuramic acid dimers
- N-acetylglucosamine has short side-chains of peptides
- The peptide side-chains are cross-linked to from a latticework, providing the cell with strength
3
Q
What are the classes of Penicillin?
A
- Penicillins G & V
- not very useful; P.V. easily breaks down in stomach since it is orally taken - B-lactamase-resistant Penicillins
- Methicillin, Oxacillin, Nafcillin, Cloxacillin, Dicloxacillin - Broad-spectrum Penicillins
- Ampicillin & Amoxicillin - Extended-spectrum Penicillins
- Carbenicillin, Ticaracillin, Azlocillin, Piperacillin
- Treats a lot of Gram negative bacteria
4
Q
Describe Cephalosporins and give examples for them
A
- Comes from Cephalosporium Acremonium
- Works like Penicillins
- Oral: Cephalexin
- Parenteral: Cefuroxime and Cefotaxime
5
Q
What are the bacterial folate antagonists?
How do they work?
A
Sulphonamides and Trimethoprim
- They inhibit the folate pathway in bacteria
- They cannot harm the human host as we do not require the use of folate system, as we get it in our diet
6
Q
Describe Aminoglycosides and give examples for them
A
- Streptomycin, Kanamycin, Neomycin, Gentamycin
- Form ionic bonds at the cell surface
- Penetrate the cell wall by a transport mechanism across the cell membrane
- Diffuse into the cytoplasm and then binds to the bacterial ribosomes at either:
a) the interface between the assembled 30S/50S subunits
b) directly to the individual 30S/50S subunits
and inhibits protein synthesis/misreading of mRNA - They are very toxic, could kill the bacteria at 5 units, and could be toxic for the human at 6 units; this toxicity could result in renal failure
