Antibiotics Flashcards
beta-lactams mechanism of action
- inhibit transpeptidation step in PG synthesis
- bind penicillin-binding proteins
- stimulate autolysins
beta-lactams resistance mechanisms
- gram-negative outer membrane (intrinsic)
- Porin Mutations
- beta-lactamases
- modify target
Examples of beta-lactams
- Penicillin
- Ampicillin
- Cefobid
- Augmentin
Glycopeptides mechanism of action
- inhibit transglycosylation and transpeptidation steps in PG synthesis by binding D-Ala to D-Ala
Glycopeptides Resistance Mechanisms
- Gram negative outer membrane
- modify target (ex substitute D-Ala-D-lactate for D-Ala-D-Ala)
beta-Lactams spectrum of activity
- gram positive and depending on the agent gram negative
Glycopeptides Spectrum of Activity
- mainly just Gram Positive
Examples of Glycopeptides
- Vancomycin
- Teichoplanin
- Daptomycin
Aminoglycosides Mechanism of Action
- bind 16S rRNA in 30S subunit of the bacterial ribosome
Aminoglycosides Resistance Mechanisms
- Inactivation of antibiotic by adding groups
Aminoglycosides Spectrum of Activity
- Broadly Bactericidal
Examples of Aminoglycosides
- Kanamycin
- Gentamicin
- Streptomycin
Tetracyclines Mechanism of Action
- bind 16S rRNA in 30S subunit of bacterial ribosome
- disrupt bacterial membrane
Tetracyclines Resistance Mechanism
- inactivation of antibiotic
- ribosome protection
- efflux system
Tetracyclines Spectrum of Activity
- Broadly bacteriostatic
- some protozoa
Examples of Tetracyclines
- Tetracycline
- Doxycycline
Macrolides/Lincosamides Mechanism of Action
- bind 23S rRNA in 50S subunit of bacterial ribosome
Macrolides/Lincosamides Resistance Mechanism
- methylation of target
- efflux
Macrolides/Linosamides Spectrum of Activity
- Bacteriostatic for most
- bactericidal of some gram-positive bacteria
Examples of Macrolides/Linosamides
- Erythromycin (macrolide)
- Lincomycin (lincosamide)
- Clindamycin (lincosamide)
Steptogramins Mechanism of Action
- bind 23S rRNA in 50S subunit of bacterial ribosome
Streptogramins Resistance Mechanism
- inactivation of antibiotic by removing groups
Streptogramins Spectrum of Activity
- bacteriostatic individually
- bactericidal in combination (used of multi drug-resistance enterococcal infections)
Examples of Streptogramins
- Synercid
Fluoroquinolones Mechanism of Action
- bind DNA gyrase
Fluoroquinolones Resistance Mechanisms
- efflux
- reduced uptake
- mutation in DNA gyrase
Fluoroquinolones Spectrum of Activity
- broadly Bactericidal
- can enter phagocytes to kill intracellular bacteria
Examples of Fluoroquinolones
- Ciprofloxacin
- Norfloxacin
Rifampin Mechanism of Action
- binds beta subunit of bacterial RNAP
Rifampin Resistance Mechanisms
- mutation in RNAP
Rifampin Spectrum of Activity
- broadly antibacterial
- effective against mycobacteria
Examples of Rifampin
- Rifampin
- Rifadin
Trimethoprim/Sulfonamides Mechanism of Action
- inhibit enzymes responsible of tetrahydrofolate production
Trimethoprim/Sulfonamides Resistance Mechanism
- mutations alter affinity of target enzymes
Trimethoprim/Sulfonamides Spectrum of Activity
- broadly antibacterial
- some fungi and protozoa
Examples of Trimethoprim/Sulfonamides
- Bactrim
- Septra
Metronidazole Mechanism of Action
- nicks bacterial DNA and interferes with DNA replication
Metronidazole Resistance Mechanism
- decreased production of flavodoxin gene
Metronidazole Spectrum of Activity
- antibacterial (mainly anaerobes)
- antiprotozoal
Examples of Metronidaole
- Flagyl
Oxazolidinones Mechanism of Action
- bind 50S ribosomal subunit
Oxazolidiones Resistance Mechanism
- mutation in 23S rRNA genes
Oxazolidinones Spectrum of Activity
- bacteriostatic
- broad spectrum against gram-positive and mycobacteria
Examples of Oxazolidinones
- Zyvox
