Module 2 Pharm-Chapter 70 Flashcards
When referring to antibiotics versus antimicrobials, which includes compounds which were made by microorganisms only (does not include those made in labs)?
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)
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: a
It is the ability of a drug to injure the target cell without injuring other nearby cells.
True or false: human cells are enclosed in a cell wall?
False. They are not contained within a cell wall (unlike bacteria) thus they are not affected by antimicrobials designed to “hurt” the cell wall.
Narrow-spectrum antibiotics treat _____ species.
a few
Broad spectrum antibiotics treat ____ species.
a lot or a variety of
Bactericidal mechanisms of action:
kill the bacteria
Bacteriostatic mechanism of action:
slows growth of bacteria
In terms of drug resistance, does the patient or the microbe become resistant to the antibiotic?
Answer: the microbe becomes resistant
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: b)inside the cell
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: a,c,d
NDM can inactivate basically all beta-lactam antibiotics. The genes it has for resistance determinants can be transferred to other bacteria.
Spontaneous mutations typically confer resistance to _____ drug/drugs.
a) one
b) multiple
c) none
Answer: a)one
Spontaneous mutations are random changes in the microbe DNA which will gradually increase resistance. Additional mutations confer greater resistance.
When DNA is transferred from one bacteria to another this is called what?
a) spontaneous mutation
b) conjugation
c) translation
d) transcription
b)conjugation
The donor organism must have two DNA segments (one for drug resistance and one for sexual apparatus needed for DNA transfer).
What type of bacteria is prone to conjugation?
a) gram negative
b) gram positive
Answer: a) gram-negative
Conjugation usually confers resistance to ______ drug/drugs.
a) one
b) multiple
c) none
answer: b)multiple
True or false: antibiotic use promotes drug-resistance?
True. ALL ANTIMICROBIALS promote resistance.
True or false: antibiotics do not directly cause drug-resistance?
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).
While all antimicrobials promote drug resistance, which type (narrow or broad spectrum) are worse for this type of promotion?
Answer: broad spectrum as they kill more bacteria so they facilitate the emergence of more resistant organisms
Superinfections are:
New infection which appears during treatment of primary infection
What is a quick, simple, and versatile method to identify bacteria?
a) gram-stain
b) PCR
c) culture
Answer: a)gram-stain
Which sampling method is most specific and sensitive?
a) gram-stain
b) PCR
c) culture
answer: b)PCR
True or false, drug sensitivity testing is common but not always needed?
True. Testing is indicated when organism is one in which resistance is likely.
Effective treatment requires antibiotic at the site of infection in concentrations (greater/less) than the MIC and preferably (______) times the MIC.
Answer: greater and 4-8 times greater than the minimal inhibitory concentration (MIC)
Where are infections difficult to treat?
a) tumor
b) abscess
c) brain
d) one or more of above
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
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: b)Combination of two drugs is equal to the sum of the two drugs alone
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: a)Effect of combo is greater than sum of the effects of the two drugs alone
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: c)Combination of two is less effective than one agent alone
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 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
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 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.
True or false: TB is treated with multiple drugs in order to suppress the emergence of resistant bacteria.
True.
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: b)fever in immune compromised patient
