Module 2 Pharm-Chapter 70

Question 1

When referring to antibiotics versus antimicrobials, which includes compounds which were made by microorganisms only (does not include those made in labs)?

Answer 1

Answer: antibiotics are compounds which are made by microorganisms ONLY

Antimicrobials: include natural and synthetic compounds (so those made by microbes and within a lab are included)

Question 2

What is selective toxicity?

a) killing pathogens without harming host
b) killing only one specific bacteria
c) toxic in some patients but not in others
d) none of the above

Answer 2

answer: a

It is the ability of a drug to injure the target cell without injuring other nearby cells.

Question 3

True or false: human cells are enclosed in a cell wall?

Answer 3

False. They are not contained within a cell wall (unlike bacteria) thus they are not affected by antimicrobials designed to “hurt” the cell wall.

Question 4

Narrow-spectrum antibiotics treat _____ species.

Answer 4

a few

Question 5

Broad spectrum antibiotics treat ____ species.

Answer 5

a lot or a variety of

Question 6

Bactericidal mechanisms of action:

Answer 6

kill the bacteria

Question 7

Bacteriostatic mechanism of action:

Answer 7

slows growth of bacteria

Question 8

In terms of drug resistance, does the patient or the microbe become resistant to the antibiotic?

Answer 8

Answer: the microbe becomes resistant

Question 9

Where do most antimicrobials work/what is their site of action?

a) outside the cell
b) inside the cell
c) in the plasma
d) other site

Answer 9

answer: b)inside the cell

Question 10

NDM-1 is capable of:

a) inactivating beta-lactam antibiotics
b) activating beta-lactam
c) has genes that code for resistance determinants
d) transferring resistance to other bacteria
e) one or more of above

Answer 10

answer: a,c,d

NDM can inactivate basically all beta-lactam antibiotics. The genes it has for resistance determinants can be transferred to other bacteria.

Question 11

Spontaneous mutations typically confer resistance to _____ drug/drugs.

a) one
b) multiple
c) none

Answer 11

Answer: a)one

Spontaneous mutations are random changes in the microbe DNA which will gradually increase resistance. Additional mutations confer greater resistance.

Question 12

When DNA is transferred from one bacteria to another this is called what?

a) spontaneous mutation
b) conjugation
c) translation
d) transcription

Answer 12

b)conjugation

The donor organism must have two DNA segments (one for drug resistance and one for sexual apparatus needed for DNA transfer).

Question 13

What type of bacteria is prone to conjugation?

a) gram negative
b) gram positive

Answer 13

Answer: a) gram-negative

Question 14

Conjugation usually confers resistance to ______ drug/drugs.

a) one
b) multiple
c) none

Answer 14

answer: b)multiple

Question 15

True or false: antibiotic use promotes drug-resistance?

Answer 15

True. ALL ANTIMICROBIALS promote resistance.

Question 16

True or false: antibiotics do not directly cause drug-resistance?

Answer 16

True.

Drugs make conditions favorable for overgrowth of microbes that have acquired mechanisms needed for resistance. (Make the environment suitable for the bad bacteria to proliferate).

Question 17

While all antimicrobials promote drug resistance, which type (narrow or broad spectrum) are worse for this type of promotion?

Answer 17

Answer: broad spectrum as they kill more bacteria so they facilitate the emergence of more resistant organisms

Question 18

Superinfections are:

Answer 18

New infection which appears during treatment of primary infection

Question 19

What is a quick, simple, and versatile method to identify bacteria?

a) gram-stain
b) PCR
c) culture

Answer 19

Answer: a)gram-stain

Question 20

Which sampling method is most specific and sensitive?

a) gram-stain
b) PCR
c) culture

Answer 20

answer: b)PCR

Question 21

True or false, drug sensitivity testing is common but not always needed?

Answer 21

True. Testing is indicated when organism is one in which resistance is likely.

Question 22

Effective treatment requires antibiotic at the site of infection in concentrations (greater/less) than the MIC and preferably (______) times the MIC.

Answer 22

Answer: greater and 4-8 times greater than the minimal inhibitory concentration (MIC)

Question 23

Where are infections difficult to treat?

a) tumor
b) abscess
c) brain
d) one or more of above

Answer 23

answer a,b,c

Also note: foreign materials present near infection may cause phagocytes to react to those items (artificial heart valve) rather than to the actual bacteria

Question 24

An additive antimicrobial response results in:

a) the effect being greater than the sum of the two drugs independently
b) the effect being the sum of the two drugs independently
c) the effect being less than the sum of the two drugs independently
d) none

Answer 24

Answer: b)Combination of two drugs is equal to the sum of the two drugs alone

Question 25

An potentitive antimicrobial response results in:

a) the effect being greater than the sum of the two drugs independently
b) the effect being the sum of the two drugs independently
c) the effect being less than the sum of the two drugs independently
d) none

Answer 25

Answer: a)Effect of combo is greater than sum of the effects of the two drugs alone

Question 26

When two drugs are used together and antagonism occurs:

a) the effect being greater than the sum of the two drugs independently
b) the effect being the sum of the two drugs independently
c) the effect being less than the sum of the two drugs independently
d) none

Answer 26

Answer: c)Combination of two is less effective than one agent alone

Question 27

If a bacteriostatic agent is used with a bactericidal drug, what can occur?

a) nothing, the combination is preferred to each drug independently
b) the bacteriostatic agent can suppress growth
c) the bacteriocidal agent inhibits the bacteriostatic agent
d) none

Answer 27

Answer b)the bacteriostatic agent can suppress growth

Bactericidal drugs only work when organisms are growing.

If growth is suppressed by bacteriostatic drug, then the effects of bactericidal agent can be reduced

Question 28

Which scenario indicates a need for multiple antibiotics:

a) resistant organism
b) unknown organism
c) immune compromised
d) superinfection
e) one or more of the above

Answer 28

Answer e)one or more of the above.

Most common indication for multiple antibiotics is initial therapy of unknown organism especially in immunocompromised.

Mixed infections (more than one organism) also may merit multiple abx.

Question 29

True or false: TB is treated with multiple drugs in order to suppress the emergence of resistant bacteria.

Answer 29

True.

Question 30

In terms of fever, when should antibiotics be initiated?

a) fever of unknown origin
b)
c) fever due to viral infection
d) none of the above

Answer 30

Answer: b)fever in immune compromised patient