Fluroquinolones Flashcards
Fluoroquinolones are a group of antibiotics that target the enzymes _ and _
Fluoroquinolones are a group of antibiotics that target the enzymes DNA gyrase and topoisomerase IV
Ciprofloxacin, norfloxacin, ofloxacin are all _ generation FQs
Ciprofloxacin, norfloxacin, ofloxacin are all second generation FQs
Levofloxacin is a _ generation FQ
Levofloxacin is a third generation FQ
Moxifloxacin is a _ generation FQ
Moxifloxacin is a fourth generation FQ
* Another fourth generation is Gatifloxacin (no longer used in US)
Which FQ would be appropriate to use for respiratory infections?
Levofloxacin and moxifloxacin
Above the diaphragm (ie respiratory infections) we want to use _ ;
Below the diaphragm we want to use _
Above the diaphragm (ie respiratory infections) we want to use levofloxacin and moxifloxacin ;
Below the diaphragm we want to use ciprofloxacin
All FQs inhibit _ and _
All FQs inhibit type II topo DNA gyrase and topoisomerase IV
* DNA gyrase is able to create negative supercoils in preparation for anticipated tension during DNA replication
* Topoisomerase IV can relax negative supercoils
Topoisomerases have a _ domain to nick the DNA strand, allowing the DNA to uncoil and relieve tension
Topoisomerases have a nuclease domain to nick the DNA strand, allowing the DNA to uncoil and relieve tension
FQs specifically target and inhibit _ domain
FQs specifically target and inhibit ligase domain of type II topoisomerase to allow the nuclease to continue nicking the DNA while removing the repair mechanism –> bacterial cell death
What are the two main ways in which resistance has been developed against FQs?
- Resistance via efflux pumps (active transport out of bacterial cells)
- Alteration of the target binding site by chromosomal mutation (may be chromosomal or via plasmids)
The most common gram-positive organism that can be resistant to FQs is _
The most common gram-positive organism that can be resistant to FQs is MRSA
The most common gram-negative organism that can be resistant to FQs is _
The most common gram-negative organism that can be resistant to FQs is Pseudomonas aeruginosa
Ciprofloxacin, norfloxacin, and ofloxacin are all Type II FQs and primarily target _
Ciprofloxacin, norfloxacin, and ofloxacin are all Type II FQs and primarily target gram-negative rods
* E.coli, H. influenzae, Moraxella catarrhalis, Klebsiella pneumoniae, Legionella, P aeruginosa, Salmonella
Of the FQs, one that is a good choice against P aeruginosa is _
Of the FQs, one that is a good choice against P aeruginosa is Ciprofloxacin
Ciprofloxacin
