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Flashcards in Control of Microbial Population 2 Deck (46)
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1

type of microbial drug that is effect on both protozoa and fungi

azoles

2

why are sulfonamides so important

they can be used to treat both prokaryotes and eukaryotes

3

what are aminoglycosides not effective against and why

not effective against anaerobes because of absent oxidative phosphorylation due to lack of oxygen

4

what are glycopeptides not effective against and why

gram negative bacteria because they are too large and can't penetrate through outer membrane

5

what are nitroimidazoles not effective against and why

aerobes because they require activation by flavodoxin which is found only in anaerobes

6

what are penicillins and cephalosporins not effective against and why

these things target particular structure which is the cell wall

mycoplasma because it lacks cell wall
mycobacteria because cell wall impenetrable

7

what are some challenges with fungi infections?

harder to treat, usually chronic, longer tx time, recurrence is common, eukaryotes so similar to humans

8

what was the first antifungal and are there many antifungals

azoles

not many because of challenge when it comes to treating fungi infections

9

what are some sites of target for antifungal agents

nucleic acid synthesis (flucytosine)
cell membrane
direct membrane

10

what do antifungal agents that target nucleic acids do

inhibits synthesis of DNA, RNA, and proteins

11

what antifungal targets nucleic acid and what is its mechanism?

cytosine analogue 5-fluorocytosine (uses fungal enzyme) --> 5-fluorouracil --> 5-fluorouridyllic acid --> blocks synthesis of p nucleic acids that the fungi is going to need to replicate

12

what is the difference between narrow and broad spectrum compounds

narrow - only treat one type of bacteria or fungi or virus

broad - treat several types of bacteria, fungi, or virus or even some cross over and treat both prokaryotes and eukaryotes

13

name of antifungal that targets cell membrane

polyenes e.g. amphotericin B

specifically ergosterol

14

what is the mechanism of polyenes (amphotericin B)

lipid loving compound that binds to ergosterol that create pores in the membrane causing leakage of ions out of the fungi --> cell lysis

15

which antifungal compound is fungicidal

polyenes (amphotericin B) because it actually kills the fungi

16

how does allylamines work

they are antifungals that interrupt the formation of ergosterol which is needed for cell membrane

it targets squalene epoxidase which turns squalene to lanesterol

17

example of allylamines

terbinafine

18

how do azoles work

they are antifungals that interrupt the formation of ergosterol which needed for cell membrane

it targets 14 alpha demethylase which turns lanesterol to ergosterol

19

example of azoles

fluconazole (triazole)

20

what are the two groups of azoles

imidazoles (two nitrogens)
triazoles (three nitrogens)

21

effects of azoles on fungal growth

fungistatic and fungicidal depending on species and specific compound

22

advantage of azoles

250 fold more effective against fungi sterols than against mammalian sterols

23

what antifungal targets cell wall

echinocandins eg caspofungin

24

mechanism of caspofungin

blocks (1,3) -beta-D-glucan synthetase --> prevents formation of chitin for cell wall

25

what antibiotics target metabolism

sulfonamides (inhibitors of metabolism or nucleic acid synthesis)

26

sulfonamides are derived from

prontosil

27

mechanism of sulfonamides

blocks folic acid synthesis

since bacteria synthesize their own antibiotics using PABA, sulfonamides are analogues of PABA so if taken up halts the production of folic acid

28

what two drugs synergistically inhibit the synthesis of folic acid in fungi

sulfamethoxazole and trimethoprim
TMP-SMX/SMZ

29

which antibiotics target protein synthesis in bacteria

tetracyclines, streptomycin, erythromycin, chloramphenicol

30

what antibiotics target cell wall of bacteria

beta lactams