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Flashcards in Antibiotics and Anti-fungals Deck (36)
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1

Important step in production of bacterial DNA synthesis

Production of tetrahydofolate

2

Important first step in production of THF

Paraaminobenzoate-> dihydropteroate

3

Enzyme for conversion of PABA to DHOp

DHOp synthase

4

Intermediate between DHOp and THF

Dihydrofolate

5

Enzyme in conversion of DHF to THF

DHF reductase

6

Important enzyme in bacterial DNA replication

DNA gyrase ( like our topoisomerase as releases tension)

7

Enzyme in bacterial synthesis

RNA polymerase- is different to ours but still does same job of producing RNA from DNA template

8

How is bacterial ribosome different to ours

Smaller

9

5 antibiotic classes for intracellular mechanisms

Sulphonamides
Trimethoprim
Fluoroquinolones
Rifamycins
Macrolides

10

MOA of sulphonamides

Targets DHOp synthase

11

MOA of trimethoprim

Targets DHF reductase

12

MOA of fluoroquinolones

Targets DNA gyrase

13

MOA of rifamycins

Targets bacterial RNA polymerase

14

MOA of macrolides

Inhibit bacterial ribosomes

15

Peptidoglycan synthesis

Pentapeptide added to NAM which associates with NAG to form PtG

16

How is PtG transported across membrane to form cell wall

bactoprenol

17

What forms links between PtG pentapeptides

Transpeptidases

18

5 drug classes targeting bacterial wall synthesis

Glycopeptides
Bacitracin
Beta-lactams
Lipoproteins
Polymyxins

19

MOA of glycopeptides

Binds to pentapeptides preventing PtG synthesis

20

MOA of bacitracin

Inhibits bactoprenol regeneration

21

MOA of beta lactams

Bind covalently to transpeptidases inhibiting PtG incorporation

22

MOA of lipopeptide

Disrupt Gram +ve cell walls

23

MOA of polymyxins

Bind to LPS and dsirupt gram -ve cell membranes

24

Causes of antibiotic resistance

Overprescription
Livestock farming
Lack of regulation in some areas in world
lack of development in antibiotic

25

5 methods of resistance

Production of destruction enzymes
Producing different target to drug that is resistant to action of drug
Altering the enzyme targeted by the drug which drug is ineffective to
Alterations in drug permeation to cell
Increase the amount of enzymes to decrease efficacy of the drug

26

Example of production of destruction enzymes

Beta-lactamase can hydrolyse the C-N bond of beta lactam ring

27

Can all penicillins fight against all bacteria

No there is variation amongst the classification in their efficacy against gram -ve and +ve

28

Example of producing different target to drug that is resistant to action of drug

Ecoli produce different DHF reductase that is resistant to trimethoprim

29

Example of altered enzyme

S aureus has mutation in ParC region of topoisomerase IV which is resistant to quinalones

30

Example of alterations in drug permeation

Reduction in aquaporins and increased efflux systems