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VT 199 Antimicrobial Agents Flashcards | StudBud
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VT 199 Antimicrobial Agents
Bacteriostatic
Broad-spectrum antibiotics
VT 199 Antimicrobial Agents
49 terms
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StudBud Administration
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15 plays
7/14/22
Flashcards
49 cards
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Questions
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Answers
1
Broad-spectrum antibiotics
are often used when the pathogen is known
increases risk of secondary infections
are often used when the pathogen is unknown
should always be used first before other antibiotics
2
Bacteriostatic
kills bacteria
requires host immune system to kill the bacteria
the antibiotic does most of the work clearing the infection
inhibits growth of bacteria
3
MIC is the lowest concentration that prevents growth
False
True
4
Broad-spectrum antibiotics are effective against only one species
False
True
5
Culture is
determines which abx are MOST effective against that SPECIFIC bacteria
isolation & identification of bacterial species
6
Drugs used to treat fungal infections
antibiotics
antifungals
antivirals
7
Which two are methicillin restant strains of Staphylococcus?
Methicillin-resistant S. pseudointermedius
Methicillin-resistant S. aureus
Methicillin-resistant S. epidermidis
Methicillin-resistant S. hominis
8
MRS strains are susceptible to vancomycin
False
True
9
Which of the following is true regarding the tube susceptibility test?
It is more precise than the disc susceptibility test
It is less precise than the disc susceptibility test
Shows which abx is most effective antibiotic for that specific bacteria
Shows the least amount of an abx that is effective against that bacteria
10
Semi-synthetics
Antimicrobials that are completely synthesized in a lab
Chemically altered abx, more effective than naturally occurring ones
11
Most antimicrobial agents are effective against multiple types of pathogens
False
True
12
Natural resistance
Something in the bacteria’s structure prevents an abx from being effective
A bacterial population that used to be susceptible is now resistant
13
Bactericidal
kills bacteria
requires host immune system to kill the bacteria
the antibiotic does most of the work clearing the infection
inhibits growth of bacteria
14
The functional component of ALL beta-lactam antibiotics is the beta-lactam ring
True
False
15
Acquired resistance
Something in the bacteria’s structure prevents an abx from being effective
A bacterial population that used to be susceptible is now resistant
16
Beta-lactamase
Destroys bacteria that is susceptible to beta-lactam
Destroys the beta lactam ring
Is the functional component of the beta-lactam antibiotic
Beta-lactam resistant bacteria produce this
17
Vancomycin
Have no beta-lactam ring
Target ribosomes and prevent translation on protein
Inhibition of protein synthesis kills the bacteria
Do not have selective toxicity
18
Natural antibiotics are made by a natural source
True
False
19
Methicillin
affected by beta-lactamase
NOT affected by beta-lactamase
Semi-synthetic variant of penicillin
Synthetic variant of penicillin
20
Which of the following is true regarding multiple drug resistances (MDR)?
Tend to develop in hospitals where antibiotics are commonly used
Cells that survive and grow have acquired one or more resistance mechanisms
Bacterial pathogens that are resistant to multiple antibiotics
"Superbugs" are MDR bacteria that are resistant to MANY OR ALL antibiotics
21
Antimicrobial agents are drugs that treat infections
True
False
22
Synthetics
Antimicrobials that are completely synthesized in a lab
Chemically altered abx, more effective than naturally occurring ones
23
Enzymatic destruction
drug cannot attach or binds less effectively
pump the drug out of the cell
produce an enzyme that destroys or deactivates the drug
may slow or prevent entry of the drug into the cell
24
Drugs used to treat bacterial infections
antibiotics
antivirals
antifungals
25
Drugs used to treat viral infections
antivirals
antibiotics
antifungals
26
Narrow-spectrum antibiotic
less disruption to normal flora
best used when a pathogen is unknown
should be used when susceptibility to the drug has been proven
effective against a narrow range of species
27
Most bacterial resistance is natural
True
False
28
The beta-lactam antibiotics
Effect plant and animal cells
Cause bacteria to die from osmotic lysis
inhibits bacterial enzymes that form the cross-links in peptidoglycan
Have selective toxicity
29
The MIC for each antibiotic is compared to a standardized chart
False
True
30
Prevention of penetration
produce an enzyme that destroys or deactivates the drug
drug cannot attach or binds less effectively
may slow or prevent entry of the drug into the cell
pump the drug out of the cell
31
Which of the following is true regarding the tube susceptibility test?
Determines the minimum inhibitory concentration (MIC)
Bacteria inoculated on agar for lawn growth
AKA broth dilution test
Add same amountof microorganism to tubes with increasingamount of an abx
AKA disc susceptibility test
Determines if a bacteria is susceptible or resistant to various antibiotics
32
Kirby-Bauer test requires the use of Mueller-Hinton agar only
True
False
33
Sensitivity is
determines which abx are MOST effective against that SPECIFIC bacteria
isolation & identification of bacterial species
34
Which drug classes inhibit cell wall synthesis?
Beta-lactam antibiotics
Vancomycin
Polymyxin B
Levofloxacin
35
Alteration of the drug's target site
produce an enzyme that destroys or deactivates the drug
drug cannot attach or binds less effectively
pump the drug out of the cell
may slow or prevent entry of the drug into the cell
36
The antibiotic with the lowest MIC is the antibiotic to which the bacteria is least susceptible
True
False
37
Kirby-Bauer test: diameter of zones of inhibition measured and compared to each other
False
True
38
Which of the following is true regarding acquired resistance?
Resistance usually starts as a random mutation in a single bacterial cell
bacteria have a low rate of mutation
Resisance mutation spreads through vertical and horizontal gene transfer
bacteria have a high rate of mutation
39
Administration of antibiotics puts selective pressure on the bacterial population, encouraging resistance
False
True
40
Methicillin resistant Staphylococcus strains are resistant to methicillin AND all other beta-lactam antibiotics
True
False
41
Which of the following is false regarding the development of new antibiotics?
It is difficult to develop fully synthetic antibiotics
Abx development has good financial return for pharmaceutical companies
Many microbes are difficult to culture in lab
Abx development has poor financial return for pharmaceutical companies
42
Which are the two most common mechanisms of action?
Inhibition of DNA and RNA synthesis
Disruption of plasma membrane
Inhibition of protein synthesis
Inhibition of metabolic pathways
Inhibition of cell wall synthesis
43
Vancomycin is inactivated by beta-lactamase
False
True
44
Which of the following is true regarding the Kirby-Bauer test?
AKA broth dilution test
Add same amountof microorganism to tubes with increasingamount of an abx
Bacteria inoculated on agar for lawn growth
Determines the minimum inhibitory concentration (MIC)
Determines if a bacteria is susceptible or resistant to various antibiotics
AKA disc susceptibility test
45
Rapid ejection
produce an enzyme that destroys or deactivates the drug
drug cannot attach or binds less effectively
pump the drug out of the cell
may slow or prevent entry of the drug into the cell
46
Vancomycin
is rarely used in vet med
reserved for human cases of multiple drug resistances
banned for use in food animals
has a beta-lactam ring
47
A drug that kills harmful microbes without damaging the host
Selective toxicity
Selective agent
Selective killer
Selective resistance
48
Some Staphylococcus strains became resistant tomethicillin by evolving a different shape to peptidoglycan-buildingenzyme
False
True
49
Kirby-Bauer test: If the bacteria is sensitive to more than one abx, can’t tell which abx is the MOST effective
False
True
