Antibiotics and their Targets Flashcards
What is the U.S. average antibiotic prescription per year?
0.88
(almost once a year)
What would be an ideal antibacterial drug?
- target would be a factor absent in human cells/tissues
- minimal toxicity
- bactericidal (kills bacteria)
- bacteriostatic (inhibits growth of bacteria)
- narrow spectrum to stop specific things
What are antimicrobials produced by?
live organisms and usually secondary metabolites
What is the role of antibiotics?
not completely sure- some signal molecules, some secondary metabolites that work as an inhibitor when purified
Which antibiotics inhibit cell wall?
B-lactams (rings)
- penicillins, cephicillins, cephalosporins, and carbapenems
What antibiotics inhibit ribosome?
macrolides (erythromycin, azithromycin)
tetracyclines
ahminoglycosides (streptomycin)
lincosamide (clindamycin and lincosamide)
What antibiotic inhibits DNA?
quinolones (F-substituted floxacins)
When are B-lactams used?
indication of infection
- associated with gram +
How do B-lactams work?
- cell wall inhibitor
- target the peptidoglycan
- resembles alanine so it crosslinks to PBP What is found in gram - but not in gram + and changes D-ala–D-ala side chains and breaks them
- 5 or 6 membered ring
What is another inhibitor of cell wall synthesis. (other than B-lactams)?
Vancomycin which from a glycopeptide
- doesn’t mimic alanine but still prevents crsslinking
What do rifampicin inhibit?
inhibit RNA polymerase and therefor, prevents initiation of RNA synthesis
- also TB tx because bacteria is non-growing and this antibiotic is good against non-growing
What do quinolones inhibit?
inhibit DNA gyrase
What drug is key therapy in aggressive periodontitis?
Metronidazole
(non specific and not much drug resistance)
What is the main reason community acquired resistant bacterial infections are increasing?
use in farming and unregulated disposal of excess drugs
T/F: more antibiotics, less resistance cases.
False!
more antibiotics, more resistance cases
