(1/15/15) Effects of Antibiotics on Life Cycle of Bacteria (Bailey) Flashcards Preview

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Flashcards in (1/15/15) Effects of Antibiotics on Life Cycle of Bacteria (Bailey) Deck (28):
1

type of antibiotic that actually kills the bacteria

bactericidal

2

type of antibiotic that prevents bacteria from replicating but does not kill it

bacteriostatic

3

_______ antibiotics occur more rapidly than ______ ones

-bactericidal
-bacteriostatic

4

tetracycline is a ______ antibiotic

bacteriostatic

5

penicillin is a _____ antibiotic

bactericidal

6

what are the 4 requirements of an ideal antibiotic

1. broad spectrum of activity
2. would not induce resistance
3. high therapeutic index
4. selective toxicity

7

is a high or low therapeutic index better for the host?

high (bc it means that you can have a very small, nonleathal dose of antibiotic and it will not kill the host but will kill the bacteria)

8

to achieve selective toxicity, a microbe must have _____ cell walls and enzyme replication as well as ribosome structure

unique

9

what are the five ways in which an antibiotic can inhibit bacteria

1. inhibition of cell wall synthesis
2. disruption of cell membrane function
3. inhibition of protein synthesis
4. action as antimetabolites
5. inhibition of nucleic acid synthesis

10

all penicillins have _____ _____

beta-lactane rings

11

how does penicillin disrupt cell wall synthesis?

it cause competition for the substrate and also becomes toxic to bacteria in its cleaved form

12

______ ____ _____ disrupts cell membrane function by binding to phospholipids

polymyxin B sulfate

13

antibiotic that prevents formation of initiation complex in blockage of the ribosome cycle

linezolid

14

antibiotic that blocks tRNA from attaching by binding to 30s subunit in the blockage of the ribosome cycle

tetracycline

15

antibiotic that blocks elongation but not RNA binding in the blockage of the ribosome cycle

aminoglycosides

16

antibiotic that binds to 50s to inhibit chain elongation causing the ribosome to dissociate from RNA in the blockage of the ribosome cycle

macrolides chloramphenicol

17

what is the only antibiotic that can inhibit DNA replication?

metronidazole

18

sulfa-drugs are ______

bacteriostatic

19

because of the _____ _____ exerted by antibiotics, bacteria have become resistant within one human genome

selective pressure

20

what are the three steps in the action of antibiotics?

1. drug penetrates the envelope
2. transports into the cell
3. drug binds to target

21

at which step does resistance to drugs occur?

at all three

22

what are the three mechanisms of drug resistance?

1. synthesis of enzymes that inactivate the drug
2. prevention of access to the target site
3. modification of the target site

23

many antibiotics enter the cell through _____

porins

24

some bacteria develop _____ pumps to pump the antibiotics out of them

efflux (all bacteria have these, just a matter of how strong they are)

25

what are the three ways that antibiotic resistance spreads?

1. chromosome associated resistance
2. plasmid mediated resistance
3. rapid spread of resistance

26

what are the three ways to combat an antibiotic resistant pathogen?

1. synergism
2. antagonism
3. indifference

27

failure to eliminate the pathogen could likely increase the likelihood of _______

superinfection

28

what are antibiotics not effective against?

viruses