L21: Intro to Microbials Flashcards
____: Refers to a naturally occurring compound (something produced by one microbe to eliminate another one)
____: Refers to a man-made compound that combats infections
Antibiotic
Antimicrobial
_____: reduces bacterial load of >3 logs in 24 hrs
_____: reduces bacterial load <3 logs in 24 hrs
Bactericidal
Bacterostatic
Which of the following is needed for serious or deep infections in vital organs (e.g sepsis, meningitis, pneumonia)?
A. Bactericidal
B. Bacteriostatic
A. Bactericidal
Which of the following is needed for ear infections, UTI’s, and skin infections?
A. Bactericidal
B. Bacteriostatic
B. Bacteriostatic
True or False: Beta-lactams, aminoglycosides, and fluroquinolones are bactericidal drugs
True
Beta lactams and vancomycin act on:
A. Cell Wall
B. Cell Membrane
C. DNA Synthesis
C. Direct damage
A. Cell Wall
Polymixins and Daptomycin act on:
A. Cell Wall
B. Cell Membrane
C. DNA Synthesis
C. Direct damage
B. Cell Membrane
True or False: Gram (+) organisms rely on more peptidoglycans while Gram (-) typically have an OM as barrier to drug access and express LPS
True
Sulfonamides and Fluroquinolones inhibit ___ synthesis
A. DNA
B. RNA
Rifamycins and Fidaxomicin inhibit ___ synthesis
A. DNA
B. RNA
A. DNA
B. RNA
True or False: Metronidazole causes direct damage
True
Aminoglycosides and Tetracyclines act on the __S ribosomes
Macrolides and Clindamycin act on the __S ribosomes
30 S
50 S
_____: bacterium inherently resistant
before it ever sees drug, e.g., does not express
target
A. Intrinsic
B. Transmissible
C. Inducible
A. Intrinsic
____: bacterium acquires resistance
genes on a plasmid or from a phage and is
prepared for drug
A. Intrinsic
B. Transmissible
C. Inducible
B. Transmissible
____: bacterium alters target or activates
countermeasure in response to drug exposure
A. Intrinsic
B. Transmissible
C. Inducible
C. Inducible
How do you quantify resistance?
Minimum Inhibitory Concentration (MIC)
- Lowest dose that stops visual growth at 24h
True or False: MIC90 – for a group of bacteria, the concentration
that is above 90% of their MIC
True
____: lowest dose required to kill 99.9% of bacteria
in 24h
A. MIC
B. MBC
B. Minimum bactericidal concentration (MBC)
True or False: Large gap around disc (Kirby-Bauer test) suggests sensitivity while small/no gap suggests resistance
True
____ can be thought of as the MIC above
which a given microbe is no longer sensitive to a particular drug
Breakpoint
Selecting a drug on the basis of a known
pathogen with known susceptibility is ___
therapy
___ therapy is starting a patient on your
“best guess” drug if you don’t know all these
things
rational
empiric
True or False: Empiric therapy often involves broad spectrum drugs
True
True or False: The effects of different drugs may depend on
the exposure time, the concentration, or both
True
____: Maximize
T>MIC by dosing frequently or
by infusion
A. Time Dependent
B. Concentration Dependent
C. Both Time/Concentration Dependent
A. Time Dependent
___ ___: Maximize Cmax/MIC by giving
highest dose you can (AUC will increase too)
A. Time Dependent
B. Concentration Dependent
C. Both Time/Concentration Dependent
Which gram (+) cocci and gram (-) anaerobic rod cause pneumonia?
- S. pneumoniae
- Klebsiella pneumoniae
True or False: E. coli causes UTI
True
- Gram (-) Rod
Which gram (+) anaerobic rod causes Gastroenteritis?
C. diff
True or False: N. meningitidis is a gram (-) cocci that causes meningitis
True
True or False: S. aureus (gram + cocci) causes skin and soft tissue infections
True
True or False: Pseudomonas aeruginosa is a gram(-), generally aerobic, that is commonly resistant to many first line drugs
True
True or False: MRSA is a common nosocomial or community-acquired infections/surgical infections
True
MRSA is resistant to almost all _____ drugs
beta-lactam
Which pathogen is likely to cause an infection brought on by treating a different one (superinfection)?
C. diff
- Note: spores must be eliminated too
