Fundamentals of Antimicrobial Chemotherapy

Question 1

What are the targets in antimicrobial chemotherapy?

Answer 1

Kill or inhibit microbe
Bacteria cell wall

Question 2

What is difference between Gram positive + Gram negative?

Answer 2

+ = thicker
= identified through staining

Question 3

What is gram positive + gram negative cross-linked by?

Answer 3

Chain of peptidoglycan
= gives its strength

Question 4

Describe structure of gram positive

Answer 4

Tightly cross-linked + interspersed with polysugarphosphates

Question 5

Describe structure of gram negative

Answer 5

Relatively thin
Loosely crosslinked layer = less robust = easier to get through

Question 6

What is the structure of peptidoglycan?

Answer 6

Lipopolysaccharide + lipoprotein
= prevent large hydrophilic molecules from reaching target

Question 7

What are the most important antibiotics that interfere with cell wall synthesis?

Answer 7

Glycopeptides + β-lactams

Question 8

What is bactericidal?

Answer 8

Kill bacteria

Question 9

What is bacteriostatic?

Answer 9

Inhibit growth of reproduction

Question 10

What are the different sources of antibiotics?

Answer 10

Microorganisms
Synthesis
Semisynthesis

Question 11

What is semisynthesis?

Answer 11

Produced by microorganism then chemically synthesised

Question 12

Describe penicillin
β-lactams

Answer 12

Natural + semisynthetic
Activity against gram positive + negative

Question 13

What can some bacteria produce?

Answer 13

β-lactamase which may inactivate penicillin
= open β-lactam ring

Question 14

What do all β-lactam antibiotics interfere with?

Answer 14

Final transpeptidation reaction that gives wall strength
= makes wall weak
= open to attack

Question 15

What are examples of pencillins?

Answer 15

Amoxicillin
Flucloxacillin

Question 16

Describe cephalosporins
β-lactams

Answer 16

Similar structure to penicillin
Can be modified to increase antibacterial activity
Modify to increase stability against β-lactamase

Question 17

What is an example of cephalosporins?

Answer 17

Cephalexin

Question 18

Describe clavams
β-lactams

Answer 18

Inhibits staphylococcal β-lactamase + gram negative β-lactamase
Combined with broad spectrum antibiotic

Question 19

Describe Rifamycins

Answer 19

Bactericidal
Against gram positive + negative

Question 20

What is an example of rifamycin?

Answer 20

Rifampicin

Question 21

Describe aminoglycosides

Answer 21

Inhibit bacterial protein synthesis
Range of side effects that are dose related

Question 22

What are examples of aminoglycosides?

Answer 22

Gentamicin
Tobramycin

Question 23

Describe macrolides

Answer 23

Inhibit bacterial protein synthesis
Spectrum of activity

Question 24

Why is it good that macrolides have a spectrum of activity?

Answer 24

Suitable for respiratory + soft-tissue disease

Question 25

What are examples of macrolides?

Answer 25

Erythromycin Clarithromycin

Question 26

Describe tetracyclines

Answer 26

Broad spectrum against gram positive + negative Inhibit bacterial protein synthesis

Question 27

What are the side effects of tetracyclines?

Answer 27

Chelate with Ca2+ = discolours teeth

Question 28

Describe glycopeptides

Answer 28

Active against gram positive Inhibitor of bacterial cell wall peptidoglycan synthesis Used in life-threatening infections

Question 29

What is an example of glycopeptides?

Answer 29

Vancomycin

Question 30

What are examples of gram-positive bacteria?

Answer 30

MRSA C.difficile

Question 31

Describe chloramphenicol

Answer 31

Broad spectrum bacteriostatic Inhibit bacterial protein synthesis

Question 32

Describe fusidic acid

Answer 32

Topical Against gram-positive

Question 33

Describe clindamycin

Answer 33

Against gram-positive cocci

Question 34

Describe mupirocin

Answer 34

Eradicating skin + nasal MRSA

Question 35

Describe Griseofulvin Antifungal

Answer 35

Active against dermatophytic fungi Orally Deposits in deep layers of skin

Question 36

Describe polyenes Antifungal

Answer 36

Oral thrush Mucosal membranes