Antimicrobials

Question 1

Beta Lactams inhibit what? and by?

Answer 1

Inhibt the synthesis of peptidoglycan by preventing the linkage of glycan sugar chains

Question 2

How do beta lactams prevent the cross linkage of glycan sugar chains

Answer 2

They do this by acting as competitive inhibitors to enzymes that help form peptide bomds between NAM molecules. These enzymes are known as PBP

Question 3

Name 2 examples of Beta-lactams

Answer 3

• Penicillins (PCNs)

- Cephalosporins

Question 4

Anitmicrobial that is the preferred option for treating bacterial infection

Answer 4

Beta-lactams such as penicillin, and etc

Question 5

Which betalactam is effective against gram postive and which one is more effective against gram negative

Answer 5

• Penicillins are more effective against gram postive
• Cephalosporins in later generation are generally less effective against gram positive but more effetive against gram negative.

Question 6

Glycopeptide is…

Answer 6

effective against gram postive only

Question 7

Glycopeptide inhibit what? by what?

Answer 7

Glycopeptides inhibit cell wall synthesis by binding to amino acid end of NAM molecules which prevents the cross linkage of adjacent of glycan chains.

Question 8

2nd choice after B-Lactams

Answer 8

Glycopeptides

Question 9

Examples of glycopeptides are..

Answer 9

• Telavancin
• Dalbavancin
• Oritavancin
• Vancomycin ( needs to be administered intravenously)

Question 10

Glycopeptide: Vancomycin

Answer 10

• It is not very absorbed the GI tract
• It does not work well against G- bacteria
• Resistance can be formed against this medication when the bacteria change the composition of their peptide side chain
• side effects : red men syndrome

Question 11

Bacitracin inhibt what? by what?

Answer 11

Bacitracin inhibits the transport of precursor molecules (NAM & NAG) used for the synthesis of peptidoglycan

Question 12

Bacitracin is used only where and why

Answer 12

Bacitracin is used only on the surface of the skin due to its toxicity

Question 13

Aminoglycosides are not effective against? why?

Answer 13

• anaerobes (enterocci and stretococci)

- b/c they enter bacterial cells by a process that requires respiratory metabolism

Question 14

How do Aminoglycosides work?

Answer 14

Aminoglycosides work by irreversibly binding to the 30S ribosomal subunit causing to distort and malfunction

Question 15

Examples of Aminoglycosides

Answer 15

• Streptomycin
• Gentamycin
• Tobramycin

Question 16

Name some side effects Aminoglycosides cause

Answer 16

• Hearing loss
• Kidney damage
• Vertigo ( dizzy )

Question 17

Aminoglycosides can be used synergistically with

Answer 17

penicillin

Question 18

Tetracyclines inihibit what?

Answer 18

inhibit bacterial protein synthesis by preventing the association of aminoacyl-tRNA with the bacterial ribosome

Question 19

Tetracyclines are effective against

Answer 19

Certain g+ and g- bacteria

Question 20

Tetracyclines…?

Answer 20

• Tetracyclines reversibly bind to the 30S ribosomal subunit and prevent the continuation of translation.
• P

Question 21

Bacteria can resist ________ by increasing the efflux of this drug from the cell.

Answer 21

they can resist tetracyclines

Question 22

What is used when tetracycline resistanceoccurs

Answer 22

Glycylclines

Question 23

Macrolides are effective against

Answer 23

Macrolides are effective against many gram+ as well as most common causes of atypical pneumonia

Question 24

Macrolides reversibly..

Answer 24

Macrolides reversibly bind to 50S ribosomes and prevent the translation from continuing.

Question 25

Macrolides are not effective against

Answer 25

members of the Enterobacteriaceae b/c they can’t penetrate the outer membrane

Question 26

Examples of Macrolides are?

Answer 26

• Erythromycin
• Clarithmythroicn
• Azithromycin

Question 27

What is the medication of choice for patients allergic to penicillins

Answer 27

Penicillins

Question 28

Fidaxomicin is

Answer 28

A new bactericidal antibiotic that interferes with transcription by binding to RNA polymerase

Question 29

Fidaxomicin passes

Answer 29

• passes through the intestinal tract without being absorbed and is particularly useful for treating C.difficile infection

Question 30

Polymyxins are effective against

Answer 30

Polymyxins are effective against gram-negative bacteria by damaging cell membranes toxicity limits their use

Question 31

Polymyxins bind to

Answer 31

the membranes of gram-negative cells

Question 32

Fluoroquinolones are effective against what?

Answer 32

Are effective against a wide variety of bacteria including both gram+ and gram- organisms

Question 33

Fluoroquinolones are?

Answer 33

Synthetic compounds that inhibit one or more of a group of enzymes called topoisomerase which maintains the supercoiling of DNA within the bacterial cell

Question 34

Examples of Fluoroquinolones

Answer 34

Ciprofloxacin
Levofloxacin
Moxifloxacin

Question 35

Rifamycins are?

Answer 35

are bactericidal effective against many Gram+ and some Gram- organisms as well as members of the genus Mycobacterium

Question 36

Rifamycins are primarily used to treat what?

Answer 36

• Tuberculosis

- Hansen’s disease (leprosy)

Question 37

Rifamycins do what?

Answer 37

are antibiotics that block bacterial RNA polymerase from initiating transcription

Question 38

Metronidazole is?

Answer 38

a synthetic compound that interferes with DNA synthesis and function.

Question 39

Tetracyclines inhibt what?

Answer 39

inhibit bacterial protein synthesis by preventing the association of aminoacyl-tRNA with the bacterial ribosome

Question 40

Macrolides inhibit what?

Answer 40

protein synthesis by binding to the 30s RNA