Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
|
Antimicrobial spectrum, whether broad or narrow, is defined by:
a) drug resistance b) gram stain c) AUC |
Antimicrobial spectrum, whether broad or narrow, is defined by:
b) gram stain |
|
|
The activity of bactericidal and bacteriostatic drugs varies depending on the organism and (blank).
|
The activity of bactericidal and bacteriostatic drugs varies depending on the organism and drug concentration.
|
|
|
Determine if each of the following sentences describes concentration-dependent killing (CDK) or tim-dependent killing (TDK).
(1) The more the drug concentration exceeds the MIC, the greater the rate of killing. (2) It is important to maximize AUC/MIC ratio. (3) Beta-lactams exhibit this type of killing. (4) It is important that the drug concentration stay above the MIC for as long as possible. (5) Aminoglycosides exhibit this type of killing. (6) Increasing the drug concentration from 4x MIC to 64x MIC is not beneficial. (7) Rate of killing is dependent on how long the drug concentration stays above the MIC. |
(1) The more the drug concentration exceeds the MIC, the greater the rate of killing = CDK
(2) It is important to maximize AUC/MIC ratio = CDK (3) Beta-lactams exhibit this type of killing = TDK (4) It is important that the drug concentration stay above the MIC for as long as possible = TDK (5) Aminoglycosides exhibit this type of killing = CDK (6) Increasing the drug concentration from 4x MIC to 64x MIC is not beneficial = TDK (7) Rate of killing is dependent on how long the drug concentration stays above the MIC = TDK |
|
|
Describe the post-antibiotic effect.
Do most antiobiotics have a PAE for Gm(+) or Gm(-) organisms? |
Post-antibiotic effect is the pharmacodynamic concept that bacteria do not immediately resume growth once the antibacterial drug concentration drops below the MIC.
Most antibiotics have a PAE for Gm(+) organisms. |
|
|
These 2 antibiotics are the only drugs that exhibit large post-antibiotic effects for Gm(-) organisms.
|
(1) fluoroquinolones
(2) aminoglycosides |
|
|
What are the 5 main mechanisms of action of chemotherapy?
|
(1) cell-wall synthesis inhibitors
(2) protein synthesis inhibitors (3) agents affecting nucleic acid metabolism (4) anti-metabolites (5) agents affecting membrane permeability |
|
|
The outer membrane of a Gm(-) organism prevents entry of antibiotics. These antibiotics, then, are limited to working on Gm(+) organisms.
This is an example of: a) intrinsic drug resistance b) acquired drug resistance |
The outer membrane of a Gm(-) organism prevents entry of antibiotics. These antibiotics, then, are limited to working on Gm(+) organisms.
This is an example of intrisic drug resistance. |
|
|
TRUE or FALSE
A large-step random mutation is a slow process that leads to increased drug resistance over time. |
FALSE
A MULTI-step random mutation is a slow process that leads to increased drug resistance over time. |
|
|
One critical mutation occurs in a bacteria over a course of 2 days. This mutation leads to total drug resistance.
This is an example of: a) multi-step mutation b) large-step mutation c) intrinsic resistance |
One critical mutation occurs in a bacteria over a course of 2 days. This mutation leads to total drug resistance.
This is an example of b) large-step mutation |
|
|
Spread of penicillinase production among members of S. aureus is an example of:
a) multi-step mutation b) transformation c) transduction |
Spread of penicilinase production via bacteriophages among members of S. aureus is an example of:
c) transduction |
|
|
S. pneumoniae and N.meningitides are the only 2 major competent pathogens capable of:
a) transduction b) transformation c) conjugation |
S. pneumoniae and N.meningitides are the only 2 major competent pathogens capable of:
b) transformation Transformation is the acquisition from the environment of genetic material, which may code for drug resistance. |
|
|
What are the 3 biochemical mechanisms of drug resistance discussed in class?
|
(1) decreased intracellular concentration of a drug due to either decreased entry or increased efflux
(2) inactivation of drug by bacterial enzymes (3) decreased affinity of a receptor or enzyme for a drug |
|
|
Describe an additive response effect of antibacterial combinations.
|
If an antibacterial combination has an additive effect, the combination of drugs is not significantly better at killing the bacteria compared to one of the drugs alone.
Adding a second drug does not enhance the killing effect of the first drug, and combining the drugs only increases the possibiity of adverse effects by exposing the patient to an additional antibacterial. |
|
|
Using tetracycline and penicillin in combination will result in a(n):
a) additive effect b) antagonistic effect c) synergistic effect |
Using tetracycline and penicillin in combination will result in an:
a) antagonistic effect Tetracycline is bacteriostatic and penicillin requires actively growing bacteria to be efficacious, therefore, tetracycline blunts penicillin's efficacy. |
|
|
The cornerstone of chemotherapy is the concept of:
|
The cornerstone of chemotherapy is the concept of:
SELECTIVE TOXICITY - injuring the invading organism without injury to the host |
|
|
In what circumstances would you prescribe a combination of antibacterials?
|
1) mixed bacterial infection and a single drug is not effective
2) to delay emergence of drug resistance (e.g. TB, HIV) 3) Enhance activity against specific pathogens (synergism) 4) therapy of severe infection of unknown etiology |
|
|
Do the following antibacterials exhibit concentration-dependent killing or time-dependent killing?
Which ones have a large PAE for Gm(-) bacteria? 1) aminoglycosides 2) fluoroquinolones 3) B-lactams |
1) aminoglycosides: CDK; large PAE for Gm(-)
2) fluoroquinolones: CDK; large PAE for Gm(-) 3) B-lactams: TDK |
|
|
What are the 3 main types of toxicity associated with chemotherapeutic agents?
|
1) direct toxicity (to hair cells of the ear, for example)
2) allergic (often associated with anti-bacterials) 3) superinfection (candidiasis, pseudomembranous colitis caused by C.diff toxin) |
|
|
When a bacteria becomes resistant to a drug by transduction, transformation or conjugation, this is an example of:
a) intrinsic resistance b) acquired drug resistance |
When a bacteria becomes resistant to a drug by transduction, transformation or conjugation, this is an example of:
b) acquired drug resistance |
|
|
Identify the following sentences as the definition of either transduction, transformation or conjugation.
1) acquisition from the environment of genetic material coding for drug resistance by competent bacteria 2) transmission of drug resistance via bacteriophage 3) sexual exchange of genetic material |
1) acquisition from the environment of genetic material coding for drug resistance by competent bacteria = TRANSFORMATION
2) transmission of drug resistance via bacteriophage = TRANSDUCTION 3) sexual exchange of genetic material = CONJUGATION |
