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20 Cards in this Set
- Front
- Back
Which antimicrobials inhibit cell wall synthesis?
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- penicillins
- cephalosporins - carbapenems - monobactams (aztreonam) - vancomycin |
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Which antimicrobials alter nucleic acid metabolism?
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- rifamycins
- quinolones |
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Which antimicrobials inhibit folate metabolism?
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- trimethoprim
- sulfonamides |
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Which antimicrobials inhibit protein synthesis?
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- chloramphenicol
- tetracyclines - glycylcycline (tigecycline) - macrolides - clindamycin - streptogramins (quinupristin/dalfopristin) - oxazolidinones (linezolid) - aminoglycosides |
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What are the miscellaneous antimicrobials?
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- metronidazole
- daptomycin - polymyxins |
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What is the magic bullet against gram NEGATIVE bugs?
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Aztreonam = a monobactam that can be used in penicillin allergic pts
- often used in combo w/vancomycin or clindamycin to cover gram postivies |
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What is the magic bullet against gram POSITIVE bugs?
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Vancomycin
-IV admin - used in penicillin-allegic pts - causes red man syndrome (nonimmunologic release of histamine giving red rash over torso and itching skin) - complexes with D-alanine D-alanine to inhibit transpeptidation - acts synergistically with the aminoglycosides - not readily absorbed, useful for Clostridium dificile |
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What are the types of protein inhibitors? (7)
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- AMINOGLYCOSIDES
blocks initiation of translation and causes the misreading of mRNA - TETRACYCLINES blocks the attachment of tRNA to the ribosome - STREPTOGRAMINS interfere with a distinct step of protein synthesis - MACROLIDES prevents the continuation of protein synthesis - CHLORAMPHENICOL prevents peptide bonds from being formed - LINCOSAMIDES prevents the continuation of protein synthesis - OXAZOLIDINONES thought to interfere with the initiation of protein synthesis |
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How do rifamycins work?
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Inhibit the beta subunit of DNA-dependent RNA polymerase (binding does not allow initiation of chain formation in RNA synthesis)
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How do quinolones work?
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inhibit the activity of topoisomerases, which are responsible for supercoiling DNA (DNA gyrase) and relaxing the supercoilded DNA (topoisomerase IV)
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Which steps of folate metabolism are inhibited by sulfonamides?
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dihydropteroate diphosphate + PABA --> dihydropteroic acid [dihydropteroic acid]
- sulfonamides interfere with this initial step by inhibiting dihydropteroic aci |
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Which steps of folate metabolism are inhibited by trimethoprim?
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dihydrofolic acid --> tetrahydrofolic acid [dihydrofolate reductase]
- trimethoprim interferes with this late step by inhibiting dihydrofolate reductase |
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How does daptomycin work?
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- calcium dependent binding and insertion of the lipophilic tail into GRAM POSITIVE cytoplasmic membrane
- oligomerization and channel formation occur - ion leakage and collapse of organism leads to cell death |
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How does metronidazole work?
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- enters a bacterium where, via the electron transport protein ferrodoxin, it is reduced
- then binds to DNA and causes DNA breakage |
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Name 5 agents that inhibit synthesis of bacterial cell walls
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- penicillins
- cephalosporins - carbapenems - monobactams (aztreonam) - vancomycin |
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Name 7 agents that affect the function of 30S and 50S ribosomal subunits to cause reversible inhibition of protein synthesis
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- chloramphenicol
- tetracyclines - glycylcyclines (tigecycline) - macrolides - clindamycin - streptogramins (quinupristin/dalfopristin) - oxazolidinones (linezolid) - binds to the 23S ribosomal subunit of the 50S ribosome |
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Name an agent that binds to the 30S ribosomal subunit and alters protein synthesis
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aminoglycosides
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Name two agents that affect bacterial nucleic acid metabolism
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- rifamycins (inhibit RNA polymerase)
- quinolones (inhibit topoisomerase IV and DNA gyrase) |
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Name two agents that block essential enzymes of folate metabolism
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- trimethoprim
- sulfonamides |
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Name the three miscellaneous agents
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-daptomycin
-metronidazole - polymyxins |