Antimicrobial Chemotherapy 1 Flashcards Preview

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Flashcards in Antimicrobial Chemotherapy 1 Deck (64)
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1

What are antibiotics only active against?

Bacteria

2

What are bactericidal?

Antimicrobial that kills bacteria (penicillins)

3

What does sensitive mean?

An organism is sensitive if it is inhibited or killed by the antimicrobial available at the site of infection

4

What is minimal bactericidal concentration (MBC)?

Minimum concentration of antimicrobial needed to kill a given organism

5

What is bacteriostatic?

Antimicrobial that inhibits the growth of bacteria

6

What does resistant mean?

Organism is resistant if it is not killed or inhibited by the antimicrobial available at the site of infection

7

What is minimal inhibitory concentration (MIC)?

Minimum concentration of antimicrobial needed to inhibit the growth of a given organism

8

What are the routes of antimicrobial administration?

Topical (applied to a surface such as the skin)

Systematic (taken internally, such as orally or parentally)

Parenteral (administered intravenously or intramuscularly)

9

What is parenteral administeration?

Administered intravenously or intramuscularly

10

What can antibiotics do to bacteria?

Kill or inhibit it

11

What are the 3 areas of bacterial metabolic activity that antibiotics can act on?

Inhibition of cell wall synthesis

Inhibition of nucleic acid synthesis

Inhibition of protein synthesis

12

Why are humans not harmed by antibiotics that inhibit cell wall synthesis?

Human cells do not have cell walls

13

What bacteria inhibit cell wall synthesis?

B-lactams:

Penicillins
Cephalosporins

14

How do B-lactams stop cell wall synthesis?

Disrupting peptidoglycans synthesis by inhibiting enzymes (penillin-binding proteins, PBPs) responsible for cross linking the chains

15

What proteins do B-lactams target?

Penicillin binding proteins (PBPs)

16

What do glycopeptides act on?

Gram positive bacteria, they are unable to penetrate the wall of gram negative

17

What are examples of glycopeptides?

Vancomycin

Teicoplanin

18

How are glycopeptides given and why?

Paternally because they are not absorbed from the GI tract

19

How do glycopeptides work?

Inhibit cell wall synthesis at a stage earlier than B-lactams, inhibiting the seemble of a peptidoglycan precurser

20

What do glycopeptides inhibit?

Peptidoglycan precurser

21

What allows selective action on bacteria protein synthesis?

Differences between bacterial and mammalian ribosomes

22

What are different classes of drugs used to inhibit protein synthesis?

Aminoglycans

Macrolides

Tetraclyclines

Oxazolidinones

Cyclic lippeptide

23

What do aminoglycans act on?

Gram negative bacteria

24

How do aminoglycans work?

Insert a different amino acid into the protein

25

What do macrolides act on?

Gram positive bacteria

26

What are macrolides an alternative to?

Penicillins for people who are allergic

27

How do tetracyclines work?

Masks the codon on mRNA so the tRNA cannot bind

28

What is an example of a oxazolidinone?

Linezolid

29

How do oxazolidinones work?

Prevents the starting codon on the mRNA to be recognised by tRNA

30

What is an example of cyclic lippeptide and what does it work against?

Daptomycin which works against gram positive bacteria, MRSA in particular