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43 Cards in this Set
- Front
- Back
what are the origins of antibiotics? |
Antibiotics are common metabolic products of aerobic bacteria and fungi |
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Drugs should be ______ ______they kill or inhibit microbial cells without damaging host tissues |
selectively toxic |
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what does the spectrum of an antibiotic mean? |
Range of different bacteria affected by Ab |
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describe: |
BROAD SPECTRUM: kill/inhibit wide range of gram+/-NARROW SPECTRUM: kill/inhibit mainly gram+ or gram-LIMITED SPECTRUM: effective against single species |
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what are the 5 fundamental mechanism of antibiotic action? |
Inhibition of cell wall synthesis |
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What is the anagram for the 5 fundamental mechs of antibiotic actioN? |
Pro (protein synthesis) |
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name two antibiotic classes that react to disrupt cell wall synthesis. How? |
penicillins and cephalosporins |
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what is a "r"-lactam? |
penicillins and cephalosporins - Named for their four membered ring structure |
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"r"-lactams cause _____ _____ ______ |
cell wall destruction |
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what is the spectrum of "r"-lactams? |
Some: against gram+/-, others: against either/or |
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how does vancomycin work? |
Natural product. Blocks NAM cross-linking. Effective against Gram +. Made by a class of M.O. know as Actinobacteria (make some of our most useful antibiotics) |
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what drug could you use against TB? Why? |
Isoniazid |
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Why does Vancomycin primarily target Gram +? |
because it is such a huge molecule, Gram - outer membrane prohibit it from entering. |
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what does Bacitracin do? |
Block peptidoglycan synthesis at early stages |
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what are the drugs that target the cell wall? |
"r"-lactams |
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give an example of a class of drugs that target nucleic acid synthesis. Do they have a broad, narrow, or limited spectrum? |
fluoroquinolones |
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how do drugs disrupt nucleic acid synthesis |
Block synthesis of nucleotides |
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Give an example of a drug that disrupts nucleic acid synthesis. What would you use it for treating? |
ciprofloxacin |
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what nucleic acid targeting drug would you use to treat anaerobes which are resistant to many Ab's |
metronidazole - blocks passage of DNA polymerases, must be activated by flavodoxin, which is not found in eukarotic cells, onlin in anaerobes. |
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what are some micro-orgs that you would use metronidazole to treat? |
helicobacter pylori |
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what two classes of drugs target folic acid synthesis? |
sulfonamides and trimethoprim |
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describe sulfonamides and what they're good for |
Sulfa drugs |
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describe trimethoprim and what it's good for |
Inhibits the enzymatic step immediately following the step inhibited by solfonamides in the synthesis of folic acid |
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how do drugs that inhibit protein synthesis work? |
Inhibit translation by reacting with the ribosome-mRNA complex |
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what is a class of drugs that target protein synthesis? |
Aminoglycoside Drugs (Streptomycin |
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what could you use streptomycin for? |
Streptomycin: Bubonic plague and tularemia and good antituberculosis agent |
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How does streptomycin work? |
interferes with protein synthesis |
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how do aminoglycoside drugs work? |
cause mRNA to misread, protein is incorrect |
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how do tetracycline drugs work? |
bind to ribosomes and block tRNA and protein synthesis |
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how do chloroamphenical drugs work? |
Blocks peptide bond formation and protein synthesis |
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how does erythromycin work? |
Blocks protein synthesis by attaching to the 50s ribosome prevents it from moving down the mRNA |
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Name a protein synthesis blocker that can be given in 1-2 doses. |
azithromycin (Zithromax) |
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what are the protein synthesis inhibiting drugs? |
aminoglycosides, tetracycline |
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what is an example of something that will disrupt the cell membrane function? |
surfactants such as soap |
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what are some drugs that disrupt cell membrane function? |
polymyxins |
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Describe the 5 steps of traditional antibiotic development |
Hypersensitive strain of bacterial plated on agar |
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Describe combinatorial chemistry |
Start with core structure |
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Describe rational drug design |
Use known structure of target to design drugs |
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For every Ab introduced, resistance has occurred in ______ |
1-10 yrs |
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Microbes become newly resistant to a drug after |
Spontaneous mutations in critical chromosomal genes |
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what are some ways microbes can become resistant. |
drug inactivation-enzyme deactivates the drug |
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