Term
| When a microorganism is not inhibited or killed after the application of antimicrobial measures, what does this lead to? |
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Definition
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Term
| When an antimicrobial measure is -static instead of -cidal, what is the result? |
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Definition
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Term
| Describe Innate resistance. |
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Definition
Innate resistance is due to the lack of a target or the presence of a structural defense blocking the drug target.
An example is the impotence of vancomycin against Gram Neg. bacteria. |
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Term
| This method of antimicrobial resistance requires energy. |
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Definition
| Efflux pumps. They are usually H antiporters. |
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Term
| An efficient for transport-mediated antimicrobial resistance. |
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Definition
| Decrease membrane permeability. This is usually done by regulation of the number of Outer Membrane Porins and by altering the pore size and selectivity. |
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Term
What usually initiates the change in the same target?
What usually initiates the replacement of a target? |
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Definition
Mutations change the target
Gene aquisitions replace the target |
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Term
Flouroquinolones target DNA gyrase. What happens in streptococci to resist this drug?
Note: this will be asked on the exam |
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Definition
Point mutations form in the Strep genome at gyrA, parC, parE.
The more mutations there are, the higher the level of resistance |
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Term
| Where does the point mutation occur to stop Linezolid from working? |
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Definition
| 23S rDNA. It prevents the drug from binding here. |
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Term
| This form of drug resistance is due to point mutations at katG/inhA, rpoB, or gyrA. |
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Definition
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Term
| This type of resistance is due to an alternate PBP2 (PBP2a) which is encoded by mecA. |
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Definition
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Term
| This type of resistance probably came from a bacteria that produces latate or serine from the VanA or VanB genes. |
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Definition
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Term
| What is an example of target modification where you add an entire functional group after translation? |
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Definition
MLSb phenotype occurs when there is a methylation at the 23s rRNA. This blocks the binding of drugs.
Since this involves the formation of an entire enzyme, the gene is usually aquired. |
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Term
| What is the significance of clavulanate, sulbactam, and tazobactam? |
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Definition
Some drugs actually create Beta-lactamases which breakdown Beta-lactam drugs. Clavulanate, sulbactam, and tazobactam inhibit this enzyme to allow the antibiotic to work.
These drugs also inhibit Extended Spectrum B-lactamases. |
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Term
| What is the resistance mechanism of choice for fungi? |
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Definition
| All methods except drug modification. |
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Term
| What is the resistance mechanism of choice for viruses? |
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Definition
| Point mutation of the target. |
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Term
| What is the resistance mechanism of choice for parasites? |
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Definition
| All methods except drug modification. |
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Term
| Beta-lactamases are secreted in different places depending on if it is gram positive or negative. Where does each type secrete? |
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Definition
Gram Negative secrete into the periplasm
Gram Positive secrete extracellularly. |
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