Module 6 Flashcards
what is the U.S. average of antibiotic prescription/person/year
0.88
what is an antimicrobial
a selective inhibitor of microbial cells
who formulated the idea of selective toxicity and combination therapy for resistance
Paul Ehrlich
what are the ideal characteristics of antibacterial agents
- targets bacterial factor ABSENT in human cells
- minimal toxicity
- bioavailability
- bactericidal
- bacteriostatic
what term refers to killing of bacteria
bactericidal
what term refers to inhibiting growth of bacteria
bacteriostatic
what are antibiotics
antimicrobials produced by live organisms and is usually a secondary metabolite
what do antimicrobials rely on
selective cellular inhibition
what are the 3 major targets of antimicrobials
- inhibition of bacterial cell wall synthesis
- inhibition of protein synthesis
- inhibition of nucleic acid synthesis
what antibiotic type acts on the bacteria cell wall
beta-lactams
what are examples of beta-lactams
- penicillin
- cephicillins
- carbapenems
what antibiotic types acts on the bacterial ribosomes
- macrolides
- tetracyclines
- aminoglycosides
- lincosamides
what antibiotic type acts on the bacterial DNA
quinolones
what is the #1 used antibiotic in dentistry
beta - lactams
what is the #2 used antibiotic in dentistry
erythromycin or azithromycin
what is the #3 used antibiotic in dentistry
clindamycin
what is a risk of beta - lactam
allergy
what is a risk of clindamycin
bone infection in the elderly population
what drug is good for the treatment of anaerobes in periodontitis
metronidazole
what do beta - lactams target
peptidoglycan
what are the steps of how beta - lactams function
- D-ala transpeptidation BLOCKED
- binds to PBP
- makes wall WEAKER, but only if bacteria is growing
what type of beta - lactam has a broader Gram - spectrum
penams - pencillin
what is the oral version of penicillin
penicillin V
what type of penicillin is injected and used mainly on Gram + bacteria
penicillin G
which of these is among the main reason the community acquired resistant bacterial infections are increasing?
a - use in farming, and unregulated disposal of excess drugs
b - higher use of antibiotics in hospital ICUs
c - climate change
d - patient compliance issues
a - use in farming and unregulated disposal of excess
only because community acquried
what are antibiotics as found in nature
a - all of these
b - bacterial signal molecules
c - bacterial secondary metabolites
d - produced by fungi and soil bacteria
a - all of these
what is clavulanic acid
the inhibitor of the resistance mechanism most commonly encountered for beta lactams. It is half of the ‘Augmentin’ combination. IT is another decoy - a competitive inhibitor of these bacterial secreted enzymes that can cut beta -lactam rings
vancomycin is from __ inhibitors of cell wall synthesis
glycopeptide
what is the mechanism of action of vancomycin
the individual NAM-NAG-(ala-ala) precursors are BOUND preventing crosslinks not a ‘decoy’ to penicillin binding protein like beta - lactam
which protein synthesis inhibitor is injection only
aminoglycosides
what inhibits peptidyl transfer by interfering with the A site bound aa-tRNA
chloramphenicol
what inhibits peptidyl transfer by blocking peptidyl transferase site
tetracycline
what binds to the 30S subunit, causes misreading and blocks initiation
streptomycin (aminoglycoside)
what binds to the 23S rRNA of the 50S subunit, inhibits chain translocation like clindamycin and azithromycin
erythromycin (macrolide)
what do nucleic acid synthesis inhibitors target
bacterial RNA polymerases
what do nucleic acid synthesis inhibitors bind to
beta or catalytic subunit of the RNA polymerase
what are nucleic acid synthesis inhibitors derived from
streptomyces bacteria
what does quinolone inhibit
DNA gyrase & topoisomerase IV
what are the mechanisms of quinolone resistance
- point mutations of topoisomerase targets
- permeability changes and efflux pumps
what is the suffix for quinolones
- floxacin
what is the key therapy in aggressive periodontitis
metronidazole
what is metronidazole
small nitro-imidazole compound activated only by reduction in anaerobic bacteria and protozoans
T/F sulfa drugs are typically given with one or more folic acid/ nucleic acid synthesis inhibitor
true
