Antimicrobials- Protein Synthesis Inhibitors

Question 1

What type of antimicrobials are the following and what subunit do they bind to?

Gentamycin
Amikacin
Tobramycin

Answer 1

Aminoglycosides which bind irreversibly to the 30s subunit

Question 2

How do aminoglycosides, macrolides, lincosamides, and tetracyclines, and glycylcycline work?

Answer 2

They are protein synthesis inhibitors.

Question 3

Which drugs have a post-antibacterial effect?

Answer 3

Aminoglycosides

Question 4

What are the effects of aminoglycosides, and what dose is recommended?

Answer 4

Bactericidal. I higher concentration single dose

Question 5

How do Marcolides inhibit protein synthesis?

Answer 5

1. They prevent the translocation of tRNA (ribosome cannot move forward on the mRNA which prevents the tRNA from moving from the A-site to the P-site)
2. They block initiating complex
3. Cause misreading of the mRNA template

Question 6

What type of antimicrobials are

Erythromycin
Azithromycin
Clarithromycin

Answer 6

Marcolides

Question 7

How do macrolides and lincosamides inhibit protein synthesis?

Answer 7

1. Binding reversibly to the 50S subunit and preventing transpeptidation. The amino acid at the p-site cannot be transferred to the growing peptide chain on the A site.
2. Prevent translocation

Question 8

What are the effects of macrolides and lincosamides at normal and high concentration?

Answer 8

Bacteriostatic at normal and bacteriocidal at very high (usual)

Question 9

What is the suffix for macrolides?

Answer 9

-thromyocin

Question 10

What type of antimicrobial is clindamycin?

Answer 10

Lacosamide

Question 11

What type of drugs are

Tetracycline
Doxycycline
Minocycline

Answer 11

Tetracylines

Question 12

How do tetracyclines and glycylcyclines work?

Answer 12

They reversibly bind to the 30s subunit and prevent tRNA from accessing the A site

Question 13

What are the effects of tetracyclines and glycylcyclines?

Answer 13

Bacterial static

Question 14

How are macrolides and lincosamides similar to chloramphenicol?

Answer 14

Macrolides, lincosamides, and chloramphenicol both reversibly bind to the 50s subunit and prevent transpeptidation. The amino acid at the p-site cannot be transferred to the growing peptide chain at the A-site. Both are bacteriostatic.

Question 15

What type of drug is tigecycline and how does it work?

Answer 15

Tigecycline is a glycylcycline that reversibly binds to the 30s subunit and prevents tRNA from accessing the A site.

Question 16

How do Quinupristin and Dalfopristin work?

Answer 16

Quinupristin reversibly binds to the 50S subunit and prevents translocation. The ribosome cannot advance on the mRNA and the tRNA cannot be transferred from the A-site to the P-site. Dalfopristin enhances the binding of Quinupristin.

Question 17

What are the effects of Quinupristin and Dalfopristin

Answer 17

Bactericidal

Question 18

What is the effect of linezolid?

Answer 18

Bacteriostatic

Question 19

How does linezolid work? What subunit do they bind to?

Answer 19

Binds to the 50s submit and prevents the formation of the initiation complex

Question 20

How does Chloramphenicol work?

Answer 20

Reversibly binds to the 50S subunit and blocks the transpeptidase reaction

Question 21

What other drug is given with aminoglycosides to achieve a synergistic effect and help the aminoglycoside penetrate the cell wall?

Answer 21

Cell wall inhibitors such as penicillin, cephalosporins, carbapenems, and monobactams.