Term
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Definition
destroy cell wall or prevent the synthesis of wall polymers in growing cells
**penicillins and cephalosporins, carbapenems, monobactams, Beta-lactamase inhibitors |
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Term
| Agents that affect the cell wall: |
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Definition
| Beta-lactams, vacomycin, and bacitracin |
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Term
| Mechanism of action of penicillins: |
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Definition
| Penicillins inhibit the last step of cell wall synthesis, in which a transpeptidation reaction results in a cross-linking of adjacent peptidoglycan strands (polymerization). The Beta-lactam portion of penicillin binds to the protein, preventing polymerization. When binding occurs, lysins are released which degrade previously formed peptidoglycan. |
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Term
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Definition
| "suicide inhibitors"-- They open the Beta-lactam ring hydrolytically |
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Term
| Examples of Antistaphylococcal Penicillins resistant to Beta-lactamase: |
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Definition
| oxacillin, methicillin, dicloxacillin, nafcillin |
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Term
| Examples of Aminopenicillins: |
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Definition
| ampicillin and amoxicillin-- have a broad spectrum, but are Beta-lactamase sensitive |
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Term
| Antipseudomonas penicillins: |
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Definition
**extended spectrum, but Beta-lactamase sensitive
*ex: mezlocillin and piperacillin |
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Term
| Cephalosporins mechanism of action: |
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Definition
| cephalosporins also have a Beta-lactam ring like the penicillins-- same mode of action as penicillins, but have a broader antibacterial spectrum than penicillins. Their basic (6-member dihydrothiazine ring) structure allows moderate resistance to Beta-Lactamases, but not others (cephalosporinases) |
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Term
| Examples of cephalosporins: |
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Definition
1. cefazolin
2. cephlathin
3. cefaclor
4. cefoxitin
5. cefotaxime
6. moxalactam
7. ceftriaxome
8. cefepime |
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Term
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Definition
Beta-lactams with a carbon substituted for the sulfur on the thiazolidine right of penicillins.
***Broadest spectrum of all Beta Lactams
Example: imipenem |
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Term
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Definition
Mode of action is similar to other Beta-Lactams
example: aztreonam |
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Term
| Beta-lactamase inhibitors: |
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Definition
Beta-lactams that bind to and inactivate Beta-lactamase enzymes.
*ex: clavulanic acid, sulbactam
**Clavulanate + amoxicillin = augmentin
**Clavulanate + ticarcillin = timentin |
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Term
| glycopeptide antibiotics are not effective for gram _____ bacteria |
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Definition
| gram negative-- won't pass through the outer membrane |
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Term
| Glycopeptide antibiotics method of action: |
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Definition
inhibit the use of lipid-linked cell wall intermediates in the assembly of the linear peptidoglycan molecule.
***Used for multiresistant gram positive bacteria.
*example: vancomycin |
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Term
| Bacitracin is used for gram ______ bacteria |
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Definition
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Term
| Bacitracin method of action: |
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Definition
*topically applied
*targets a lipid carrier responsible for moving peptidoglycan precursors through the cytoplasmic membrane to the cell wall
*It is a Polypeptide |
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Term
| Polymyxins are used for Gram _____ bacteria |
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Definition
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Term
| Method of action for the polymyxins: |
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Definition
**Primarily used for external treatment of local infections (eye and skin)
fatty acid portion penetrates into the hydrophobic portion of the outer membrane of gram (-) bacteria. The ring portion interacts LPS and phospholipids. Distortion of the membrane results in increased cell permeability and lysis. |
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Term
| Problems with polymyxins: |
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Definition
| Causes severe nephrotoxicity |
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Term
| Cell wall agents used for mycobacteria: |
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Definition
1. Isoniazid
2. ethionamide
3. ethambutol
4. cycloserine |
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Term
| How to isoniazid and ethionamide work? |
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Definition
| interfere with synthesis of mycolic acids (cell wall constituents) in mycobacteria |
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Term
| Ethambutol and cycloserine method of action: |
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Definition
| inhibit cell wall constituents in mycobacteria |
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Term
| Agents that interfere with nucleic acid synthesis: |
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Definition
1. quinolones,
2. novobiocin,
3. rifamycins,
4. metronidazole |
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Term
| Quinolones mechanism of action: |
|
Definition
| inhibit DNA replication--- inhibit the supercoiling DNA by binding to DNA gyrases (topoisomerases), which are enzymes that introduce negative superhelical turns into covalently circular DNA |
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Term
|
Definition
Ciprofloxacin, levofloxacin, gatifloxacin and moxifloxacin
**(anything that ends with --floxacin) |
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Term
| Novobiocin mechanism of action: |
|
Definition
| same as quinolones--inhibits DNA replication by binding to DNA gyrases, which introduce negative superhelical turns into covalently circular DNA |
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Term
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Definition
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Term
| Rifampin is used for what kind of bacteria? |
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Definition
| Mycobacterium tuberculosis |
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Term
| Rifabutin is used for what kind of bacteria? |
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Definition
| Mycobacterium avium--causes tuberculosis like symptoms |
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Term
| Rifamycins method of action: |
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Definition
| prevents RNA synthesis by binding to DNA-dependent RNA polymerase |
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Term
| Metronidazole has no significant activity against: |
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Definition
| aerobic bacteria or facultatively anaerobic bacteria |
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Term
| Metronidazole method of action: |
|
Definition
| Anaerobic bacteria reduce the compound when they take it up. The reduced form acts as a free radical that damages bacterial DNA |
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Term
| Agents that inhibit protein synthesis: |
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Definition
1. aminoglycosides
2. tetracyclines
3. macrolides
4. chloramthenicol
5. oxazolidinones
6. clindamycin
7. streptogramins |
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Term
| Examples of aminoglycosides: |
|
Definition
1. streptomycin
2. neomycin
3. kanamycin
4. gentamycin
5. tobramycin
6. amikacin
7. spectinomycin |
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Term
| Are Aminoglycosides bacteriocidal or bacteriostatic? |
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Definition
| aminoglycosides are bacteriocidal |
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Term
| Aminoglycosides can treat Gram ______ bacteria |
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Definition
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Term
| What kind of bacteria are resistant to aminoglycosides? |
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Definition
| Anaerobes--do not take up the drugs |
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Term
| examples of Tetracyclines: |
|
Definition
| tetracycline, doxycycline, minocycline |
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Term
| Tetracyclines are bacteriostatic or bacteriocidal? |
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Definition
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Term
|
Definition
1. erythromycin
2. azithromycin
3. clarithromycin |
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Term
| Macrolides are used for Gram ______ bacteria |
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Definition
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Term
| Macrolides are bacteriostatic or bacteriocidal? |
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Definition
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Term
| Chloramphenicol is used for what disease? |
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Definition
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Term
| Oxazolidinones used for what kind of bacteria? |
|
Definition
Staphylococcus, streptococcus, enterococcus
***used for strains of these bacteria resistant to penicillins, vancomycin, and aminoglycosides |
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Term
| Example of oxazolidinones: |
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Definition
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|
Term
clindamycin used for Gram ______ bacteria
what type of metabolism does the bacteria have? |
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Definition
used for Gram (-) bacteria
the bacteria are anaerobic |
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Term
| example of Streptogramins: |
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Definition
| quinupristin-dalfopristin (Synercid) |
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Term
| Streptogramins are used for what kind of bacteria? |
|
Definition
| Vancomycin resisitant E. faecium |
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Term
| How do metabolic antagonists work? |
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Definition
| they are analogs of bacterial growth factors-- the enzymes essential in the synthesis of and utilization of these factors can be inhibited by antimetabolites structurally related to the metabolites |
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Term
| Examples of metabolic antagonists: |
|
Definition
1. sulfonamides
2. trimethoprim |
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Term
| sulfonamides mechanism of action: |
|
Definition
| structural analogs of p-aminobenzoid acid (PABA). Competitively inhit incorporate PABA into folic acid which is a precursor for purines, pyrimidines, and amino acids |
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Term
| Trimethoprim mechanism of action: |
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Definition
| structural analog of dihydrofolic acid--inhibits the synthesis of folic acid |
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Term
| Clofazimine mechanism of action: |
|
Definition
| binds to mycobacterial DNA and causes damage |
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Term
| Types of bacteria clofazimine is used for: |
|
Definition
| Mycobacterium tuberculosis and M. leprae |
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Term
| Pyrazinamide (PZA) is used for what kind of bacteria? |
|
Definition
| Mycobacteria tuberculosis |
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