IA. General microbiology | 9. Antimicrobial drugs that inhibit the protein synthesis

Question 1

What are the 2 targets of drugs that inhibit the protein synthesis?

Answer 1

1. At 30S ribosomal subunit (aminoglycosides, tetracyclines)
2. At 50S ribosomal subunit (macrolides, chloramphenicol)

Question 2

I. Drugs that target 30S ribosomal subunit
1. What are the 2 drugs that target 30S ribosomal subunit?

Answer 2

1. Aminoglycosides
2. Tetracyclines

Question 3

I. Drugs that target 30S ribosomal subunit
2. What are the features of Aminoglycosides?

Answer 3

○ Bactericidal
○ Streptomycin: against TB
○ Amikacin, Netilmicin: severe system infections
○ Tobramycin, Gentamicin: parenteral or eye drops
○ Neomycin: eye drops
○ Often toxic – deafness or kidney failure

Question 4

I. Drugs that target 30S ribosomal subunit
3A. What are the features of Tetracyclines?

Answer 4

○ Chlortetracycline, doxycycline, oxytetracycline (Tetran)
○ Inhibits binding of aminoacyl-tRNA
○ Very wide spectrum (also for animals)

○ Active against IC bacterial
■ Chlamydia, Mycoplasma, Rickettsia
○ Side effects:
■ Liver failure (pregnancy), kidney failure
■ Accumulation in bones (teeth of children)
■ Severe diarrhoea, mucosal inflammation

Question 5

I. Drugs that target 30S ribosomal subunit
3B. What are the side effects of Tetracyclines?

Answer 5

■ Liver failure (pregnancy), kidney failure
■ Accumulation in bones (teeth of children)
■ Severe diarrhoea, mucosal inflammation

Question 6

II. Drugs that target 50S ribosomal subunit
1. List the drugs that target 50S ribosomal subunit

Answer 6

1. Chloramphenicol (important)
2. Macrolides (important)
3. Streptogramins
4. Ketolides
5. Oxazolidinone
6. Mupirocin

Question 7

II. Drugs that target 50S ribosomal subunit
2. What are the features of Chloramphenicol?

Answer 7

○ Streptomyces venezuelae (Ehrlich)
○ Wide spectrum → dysbacteriosis
○ Today mainly for: typhus abdominalis, amp Haem. influenzae
○ Cheap so found in developing countries
○ Per os, eye drops/ ointments

○ Side effects:
■ Bone marrow malfunction
■ “Grey baby syndrome” in newborns

Question 8

II. Drugs that target 50S ribosomal subunit
3A. What are the features of Macrolides?

Answer 8

○ Inhibit the elongation of peptide chain
○ Higher concentration: become bactericidal

○ Groups:
■ 14 membered ring: erythromycin, clarithromycin
■ 15 membered ring: azithromycin
■ 16 membered ring: josamycin

○ Wide spectrum – streptococci; Bordettella, STD, RTI, H. Pylori, Chlamydia
○ Non-toxic, cheap
○ High resistance

Question 9

II. Drugs that target 50S ribosomal subunit
3B. What are the groups of Macrolides?

Answer 9

○ Groups:
■ 14 membered ring: erythromycin, clarithromycin
■ 15 membered ring: azithromycin
■ 16 membered ring: josamycin

Question 10

II. Drugs that target 50S ribosomal subunit
4A. What are features and examples of Lincosamides?

Answer 10

• Examples: Clindamycin, lincomycin

Question 11

II. Drugs that target 50S ribosomal subunit
5. What are examples of Streptogramins?

Answer 11

Quinupristin, dalfopristin

Question 12

II. Drugs that target 50S ribosomal subunit
6. What are examples of Ketolides?

Answer 12

Telithromycin

Question 13

II. Drugs that target 50S ribosomal subunit
7. What are features of examples of Oxazolidinone?

Answer 13

E.g, Linezolid, tedizolid

Question 14

II. Drugs that target 50S ribosomal subunit
8. What are features and examples of Mupirocin?

Answer 14

MRSA decontamination