Antimicrobials

Question 1

What are the goals of successful Ab therapy?

Answer 1

1. achieve effective [Ab] at the site of infection
2. Avoid toxicity to host
3. Eradicate the organism
4. Minimize resistance
5. avoid residues in food animals

Question 2

What are some reasons to assess culture sensitivity of a bacteria?

Answer 2

1. failure of initial empirical treatment
2. serious, life threatening infection
3. possible nosocomial infection
4. relapse of infection after Ab treatment has ended
5. chronic infection

Question 3

Which method would be most accurate in determining MIC of Antibiotic for a certain bacteria?

Answer 3

E-test
-Gradual [antibiotic] increase along strip to give a specific [Ab] where growth is inhibited

(disc diffusion –> discs have fixed concentrations, doesn’t necessarily indicate this as the MIC.
Tube dilution method, MIC may actually be somewhere in between two sequential tubes where growth is in one but inhibited in the next…margin of error becomes large the higher up in two fold increase you get)