(exam 3) ch 20 Antimicrobial drugs

Question 1

what is selective toxicity?

Answer 1

selectively finding and destroying pathogens without damaging the host

Question 2

___________ is the use of chemicals to treat a disease (not just used for cancer treatment)

Answer 2

chemotherapy

Question 3

__________ is a substance produced by a microbe that in small amounts, inhibits another microbe. There are limited sources of these with human relevance.

Answer 3

Antibiotics

Question 4

__________ are synthetic substances that interfere with the growth of microbes.

Answer 4

Antimicrobial drugs

Question 5

which type of pathogen is the easiest to treat with antimicrobial drugs?

Answer 5

bacteria

Question 6

what are drugs with a narrow spectrum of microbial activity?

Answer 6

drugs that affect a limited range of microbial drugs and are usually used after the pathogen has been identified

Question 7

what are drugs with broad spectrum antibiotics?

Answer 7

affect a broad range of gram + and gram - bacteria and are often used for initial treatment to slow or kill whatever is growing

Question 8

One disadvantage to using broad-spectrum antibiotics is that they ?

Answer 8

destroy normal microbiota

Question 9

A _________ is the overgrowth of normal microbiota and overgrowth of pathogens that have developed antibiotic resistance.

Answer 9

superinfection

Question 10

A __________ is bacteria that are resistant to large numbers of antibiotics.

Answer 10

superbug

Question 11

If an antibiotic prevents bacteria from growing, then its action is termed?

Answer 11

bacteriostatic

Question 12

If an antibiotic kills microbes directly, it’s action is termed?

Answer 12

bactericidal

Question 13

Penicillin works by inhibiting ________ synthesis.

Answer 13

cell wall

Question 14

what structure in penicillin prevents the synthesis of peptidoglycan?

Answer 14

B-lactam ring

Question 15

Polypeptide antibiotics work by inhibiting ______ synthesis.

Answer 15

cell wall

Question 16

how do drugs work to inhibit protein synthesis?

Answer 16

selective toxicity which targets bacterial 70S ribosomes

Question 17

Eukaryotes have 80S ribosomes, whereas prokaryotes have ________ ribosomes.

Answer 17

70S

Question 18

The mode of action of chloramphenicol is to?

Answer 18

inhibit protein synthesis

Question 19

Aminoglycosides work by inhibiting _______ synthesis.

Answer 19

protein

Question 20

Tetracyclines work by inhibiting _______ synthesis.

Answer 20

protein

Question 21

The mode of action of lipopeptides is to?

Answer 21

injure the plasma membrane

Question 22

Antifungals which injure the plasma membrane target what?

Answer 22

sterols

Question 23

Rifamycin works by inhibiting _______ synthesis.

Answer 23

nucleic acid

Question 24

Inhibiting nucleic acid synthesis does what to the pathogen?

Answer 24

interferes with DNA replication and transcription which prevents the microbe from growing and kills it

Question 25

Sulfanilamide works by inhibiting _______ synthesis?

Answer 25

essential metabolites

Question 26

inhibiting essential metabolite synthesis does what to the pathogen?

Answer 26

stops synthesis of folic acid which is needed for nucleic acid and protein synthesis so the cell can not grow and dies

Question 27

___________ are inhibitors that block host cell receptors and block fusion of virus and cell so there is no access to the host cell.

Answer 27

entry and fusion inhibitors

Question 28

what two steps of viral replication are affected by entry and fusion inhibitors?

Answer 28

attachment and entry

Question 29

_______________ are inhibitors that prevent viral uncaring, inhibit viral DNA integration into host genome, and nucleoside analogs inhibit RNA and DNA synthesis.

Answer 29

Uncoating, genome integration and nucleic acid synthesis inhibitors

Question 30

what two steps of viral replication are affected by entry and fusion inhibitors?

Answer 30

uncoating and biosynthesis

Question 31

Nucleoside analogs affect steps in _________ because they resemble DNA or RNA but cause termination of expanding chains.

Answer 31

virus replication (biosynthesis)

Question 32

__________ are a type of assembly and exit inhibitors that block cleavage of protein precursors.

Answer 32

protease inhibitors

Question 33

__________ are a type of assembly and exit inhibitors that inhibit neuraminidase, an enzyme that is needed for some viruses to bud deem the host.

Answer 33

exit inhibitors

Question 34

which two steps of viral replication are affected by assembly and exit inhibitors ?

Answer 34

maturation and release

Question 35

__________ are produced by viral infected host cells to inhibit further spread of the infection.

Answer 35

interferons

Question 36

_________ promotes interferon production.

Answer 36

imiquimod

Question 37

in order to provide good treatment, we need to know what about pathogens?

Answer 37

pathogen sensitivities

Question 38

_________ tests the effectiveness of chemotherapeutic agents by using paper disks with a chemotherapeutic ager on a container of agar containing the organism.

Answer 38

Disk diffusion method (aka. Kirby-Bauer test)

Question 39

what do we look for to indicate the sensitivity of an organism to an antibiotic in a disk diffusion test?

Answer 39

the zone of inhibition

Question 40

what does a large zone of inhibition indicate?

Answer 40

that a pathogen is sensitive to a certain antibiotic

Question 41

_________ is a test used to determine the minimal inhibitory concentration (MIC) by using a plastic strip containing an antibiotic at varying concentrations.

Answer 41

E test (epsilometer)

Question 42

what is minimal inhibitory concentration (MIC)?

Answer 42

lowest antibiotic concentration that prevents bacterial growth

Question 43

________ is a test used to determine BOTH MIC and minimal bactericidal concentration (MBC) of an antimicrobial drug.

Answer 43

Broth dilution tests

Question 44

what is minimal bactericidal concentration (MBC) ?

Answer 44

lowest antibiotic concentration that kills bacteria

Question 45

what does the broth dilution test give valuable information about?

Answer 45

provides information that is used to prevent the overture or misuse of antibiotics by determining safe dosing

Question 46

________ reports on the susceptibility of organisms encountered clinically.

Answer 46

Antibiograms

Question 47

_________ are microbes with genetic characteristics allowing for their survival when exposed to an antibiotic; Vertical transmission of survival genes through reproduction.

Answer 47

persister cells

Question 48

how are resistance genes typically spread?

Answer 48

horizontally among bacteria on plasmids or transposons via conjugation or transduction

Question 49

_________ are bacteria that are resistant to large numbers of antibiotics (such as MRSA)

Answer 49

superbugs

Question 50

what are four mechanisms of resistance?

Answer 50

1) prevention of penetration to the target site within the microbe 2) enzymatic destruction or inactivation of the drug 3) alteration of the drug target site 4) rapid efflux (ejection) of the antibiotic before it reaches a high concentration in the cell