24 - Antibiotics

Question 1

Define antibiotic?

Answer 1

A drug that inhibits or kills bacteria

Question 2

Define microbial?

Answer 2

Term given to the types of drugs that target different microbes

• antivirals/bacterial/fungals/malarials

Question 3

What do antibiotics target in bacteria?

Answer 3

Cell wall - penicillin
Cell membrane - polymxin
Nucleic acid synthesis - sulphonamides
Protein synthesis - tetraglycines

Question 4

Usefulness of selective toxicity?

Answer 4

Prevents damage to eukaryotic cells

Exp: attacking protein synthesis in bacteria, the antibiotic will target enzymes involved only found in prokaryotes.

Question 5

Classes of antibiotics?

Answer 5

B-lactams
- penicillin

Glycopeptides
- vancomycin

Aminoglycosides

Tetraglycines

Chloramphenicol

Macrolides

Question 6

2 ways to determine antibiotics susceptibility?

Answer 6

Disc susceptibility

E-test

Question 7

What is the MIC?

Answer 7

The minimum inhibitory concentration

• the dilution of a drug that can still inhibit bacteria

Question 8

Define synergy, antagonism, indifferent?

Answer 8

Synergy - two antibiotics work better together

Antagonism - combined effect is less useful

Indifference - drug is not better alone or together

Question 9

Comparison of vaccines and antibacterial?

Answer 9

Vaccines last longer
Bacterial are more toxic
Bacterial are more effective
Both have high specificity

Question 10

How does resistance arise?

Answer 10

Mutation in the bacterias chromosomal genes

Can aquire foreign DNA:

• transfer plasmid strains between diff species
• mutation in genetic material