What are the two main ways antibiotics work?
- Cell wall synthesis inhibition
- Protein synthesis inhibition
The antibiotic __?__ interferes with our ribosomes.
Ideal antibiotic should affect __?__.
Antibiotic compounds are classified by __?__ and __?__.
- Spectrum of activity
The two spectrums of activity are __?__ and __?__.
- Broad: effective against many species
- Narrow: effective against few species
The two types of antibiotics are __?__.
- Bacteriocidal: kill target organism
- Bacteriostatic: prevent growth of organism
Bacteriocidal drugs typically only work on __?__ cells by __?__. An example of a bacteriocidal drug is __?__.
- inhibiting cell wall synthesis
- Penicillin + derivatives
How do bacteriostatic drugs aid in fighting infection?
Slowing down growth so the immune system can eliminate it.
Minimal inhibitory concentration is __?__. MLC is __?__.
- MIC: the lowest concentration of a drug needed that prevents growth
- MLC: minimum lethal concentration - sterile
Multiple drug coated disks put on a culture plate tests for __?__ and is known as __?__.
- drug susceptibility
__?__ are the five mechanisms of antibiotic action.
- Inhibit nucleic acid synthesis
- Inhibit folate synthesis
- Depolarization of membrane
- Inhibit protein synthesis
- Inhibit cell wall synthesis
Penicillin and Cephalosporin are antibiotics that work through what mechanism?
Inhibit cell wall synthesis by acting a competitive inhibitor of transpeptidase. Beta lactam ring
__?__ is the structure of the beta lactam ring.
Ampicilin and amoxicillin are derivatives of __?__ and are resistant to __?__.
- Acid hydrolysis (why they can be taken orally)
Amp and amo are __?__ spectrum and work on __?__ bacteria.
Oxacillin, dicloxacillin, and methicillin are resistant to __?__ because of __?__ but are not effective against __?__ bacteria.
- bulky side chain (always determines characteristics of cell wall inhibitors aka penicillin and derivatives)
- G (-)
What are the mechanisms of protein inhibtion synthesis? (3)
- Block transf of peptides by binding large ribosomal subunit - (Macrolides, chloramphenicols, lincosamides)(Erythromycin, azithromycin)
- Prevent 30 and 50s subunits from binding eachother - (Aminoglycosides)(Streptomycin)
- Bind small subunit and block aminoacyl-tRNA (Tetracyclines)
__?__ are the four bacterial resistance mechanisms and their mechanisms?
- Destroy antibiotic Beta lactamase
- Modifiying the antibiotic Acetylation, adenylation, phosphorylation via cellular enzymesAltering the Target Changing target site for antibiotic on target enzyme Most common in streptomycin resistance
- Eflux Removes drug from cell
__?__ are the two ways bacteria aquire resistance to antibiotics.
- Mutation (alteration of target site) occurs naturally and is selected for
- Horizontal gene transfer