Term
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Definition
-slow growing subpopulation of bacteria with distinctive traits -slow growth rate, atypical morphology, and unusual biochemical characteristics
-invade host and persist within host cells without stimulating host response or inducing lysis (can cause persistent or recurrent infections) |
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Term
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Definition
-contain sterols
-antibiotic activity directed against production of sterols |
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Term
Mechanism of Action:
Cell wall inhibition |
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Definition
1.inhibition of transpeptidation:
-beta lactams bind to binding sites that are enzymes for cell wall development (Penicillin Binding Proteins-- PBP)
2. inhibition of peptidoglycan precursor synthesis
-Vancomycin |
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Term
Mechanisms of Action:
Inhibition of Protein Synthesis
Selective for 70s complex |
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Definition
Aminoglycosides
-30s misread mRNA
-resistance due to deletion of protein receptor on 30s subunit
Tetracyclines
-30s blocks attachment of mRNA
-resistance due to deletion of protein receptor on 30s subunit
Chloramphenicol
-50s inhibits peptidyl transferase
-resistance due to enzymatic destruction |
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Term
Macrolides
Clindamycin
Pristinamycins
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Definition
50s
block elongation
may interfere with each other due to common site of activity |
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Term
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Definition
fMET-tRNA complex
-inhibits 70s initiation complex, 30s and 50s do not bind together |
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Term
Mechanism of Action:
Nucleis Acid Synthesis
Rifampin |
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Definition
Rifampin: binds DNA dependent RNA polymerase
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Term
Mechanism of Action
Inhibition of Nucleic Acid synthesis
Quinolones |
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Definition
Quinolones: blocks the action of topoisomerase (DNA gyrase)
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Term
Mechanism of Action
Inhibition of Nucleic Acid Synthesis
Trimethoprim and Pyrimethamine |
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Definition
| inhibit bacterial dihydrofolate reductase |
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Term
Mechanism of Action
Inhibition of Nucleic Acid Synthesis
Sulfonamides |
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Definition
| antimetabolite during protein synthesis |
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Term
Mechanism of Action
Inhibition of Nucleic Acid Synthesis
Metronidazole |
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Definition
| interferes with DNA replication |
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Term
Bacterial Growth Phases
Lag Phase |
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Definition
-bacteria adapt to growth conditions
-individual bacteria maturing and not yet able to divide
-synthesis of RNA, enzymes, and other molecules occurs |
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Term
Bacterial Growth Phases:
Exponential Phase |
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Definition
-cell doubling... will continue at a constant rate if not limited
-cannot continue indefinitely bc the medium will become depleted of nutrients and enriched with waste
-antibiotics work best at this phase in the growth cycle |
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Term
Bacterial Growth Phases:
Stationary Phase (Static) |
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Definition
-growth rate slows due to nutrient depletion and accumulation of toxic products
-constant value: rate of growth = rate of death |
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Term
Bacterial Growth Phases:
Death phase |
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Definition
| bacteria run out of nutrients and die |
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Term
| Factors involved with antibiotic activity |
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Definition
-concentration of antibiotic
-diffusion of the antibiotic through the outer cell membrane
-ability to resist attack by inactivating enzymes
-affinity of the antibiotic for the target enzyme |
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Term
Minimum Inhibitory Concentration (MIC)
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Definition
-lowest concentration of a given antibiotic that inhibits growth of specific organism, given as a number
-an MIC value followed by a number is the amount or level of a drug needed to inhibit that % of growth |
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Term
| Minimum Bactericidal Concentration (MBC) |
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Definition
| -lowest concentration of a given antibiotic required to kill a specific organism |
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Term
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Definition
| time that it takes for the concentration in blood plasma of a substance (antibiotic) to reach 1/2 of its steady state |
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Term
| Concentration-Dependent Killing |
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Definition
| the rate and extent of killing increases as the peak drug concentration increases |
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Term
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Definition
-bactericidal activity continues as long as the plasma concentration is greater than the minimum bactericidal concentration
-the concentration of these drugs should be maintained about MIC |
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Term
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Definition
-persistent suppression of bacterial growth after limited exposure to an antibiotic
-associated with concentration dependent killing
Mechanisms:
-slow recovery of bacteria
-persistance of antibiotic
-need for bacteria to synthesize new proteins before growth can continue |
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Term
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Definition
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Term
| Closely monitor _____ when starting or stopping ANY antibiotic in patients taking ______. |
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Definition
| INR (international normalized ratio); warfarin (blood thinner) |
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