Antibiotics

Question 1

Gram negative vs a gram positive cell envelope

Answer 1

Gram positive have a huge peptidoglycan portion and the gram negative have a small one with an additional outer membrane above that.

Question 2

How does Vancomycin work and what do we use it on?

Answer 2

This is a giant elephant of a molecule that sterically hinders the assembly of disaccharide subunits, preventing transglycosylation. These guys are very important for the treatment of multi-resistant staph and enterococcus

Question 3

How do Beta lactam antibiotics work? Big names that fall in this category?

Answer 3

These guys bind transpeptidases to stop cell wall synthesis.

Penicillin, Monobactam, Cephalosporin, and Carbapenem all fall in this group

Question 4

Bacitracin

Answer 4

Inhibits the export of PG components across the cell membrane

Question 5

Drugs that disrupt cell membranes

Answer 5

polymyxins and daptomycin

Question 6

Linezolid and what it does to bacteria

Answer 6

This is the only clinically significant drug that inhibits formation of the 70s initiation complex for protein synthesis

It is bacteriostatic for staph and enterococci but it is bactericidal for strep

Question 7

Streptomycin

Answer 7

This guy targets the 30s ribosomal subunit by causing a misread. The 70s subunit still forms but it’s wonky and can’t make proteins, and in addition, messes with membrane proteins to make them more leaky

Question 8

How do aminoglycosides work and what do we use them with?

Answer 8

They work very similarly to streptomycin but target 30s and 40s at different proteins.

Great against pseudomonas, but not that effective against most intracellular bacteria

Question 9

Spectinomycin and what we use it for

Answer 9

This is a bacteriostatic aaminocyclitol antibiotic that also causes the formation of a wonky 70s ribosome but without the misreading.

We use it exclusively for gonorrhea caused by B-lactamase-producing gonococci or to treat gonorrhea in patients allergic to penicillins.

Question 10

What are tetracyclins and when do we use them?

Answer 10

Bacteriostatic against chlamydia and mycoplasma and ricketts.

Bacterial cells take it up and it targets 30s to inhibit binding of certain a-site tRNAs

Question 11

Clindamycin is very effective against what type of bacteria?

Answer 11

Gram negative, and it binds to the 50S ribosomal subunit.