Term
| what is the difference between Gram+ and Gram- bacteria? what color do they stain? |
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Definition
Gram+ have peptidoglycan cell wall outside of cell membrane; purple
Gram- have peptidoglycan layer between plasma membrane and outer cell wall; pink |
|
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Term
| what are atypical bacteria? eg? |
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Definition
don't have a peptidoglycan cell wall
Mycoplasma and chlamydia |
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Term
| Steps in cell wall synthesis |
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Definition
1. Nam-Nag precursors formed in cytoplasm, transported to cell wall
2. Transglycosylation - polymerization of Nam-Nag complexes
3. Transpeptidation - PBP cross link aa chains of Nam-Nag |
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Term
|
Definition
| Penicillin, Cephalosporin, Carbapenems, Monobactams |
|
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Term
| what do all B-lactams have in common? |
|
Definition
Structure (B-lactam ring)
mechanism of action - inhibition of transpeptidation
Synergism w/ aminoglycosides and antagonism w/ tetracyclines |
|
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Term
| mechanisms of resistance to penicilin? |
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Definition
-B-lactamase production - attacks C-N bond and inactivates drug
-Structural changes in PBP - won't allow drug to bind
-Changes in porin structure - won't allow drug to enter bacteria |
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|
Term
| how are penicilins eliminated |
|
Definition
Renally through PSOASS
EXCEPT: Nafcilin and Oxacilin - more lipid soluble, secreted via bile |
|
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Term
|
Definition
| hypersensitivity - ranging from; simple rash, bronchospasm, urticaria, anaphalctic shock |
|
|
Term
| categories of penicillins |
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Definition
| Natural, Anti-staphylococcal(Oxipenicillins), Extended spectrum (aminopenicillins), and Anti-pseudomonal |
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|
Term
|
Definition
|
|
Term
| what penicillins are resistant to B-lactamase |
|
Definition
| Anti-staphylococcal (oxipenicillins) |
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|
Term
|
Definition
|
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Term
|
Definition
| water solublility from amine group allows them to pass through porin channels in gram- bacteria |
|
|
Term
| depot forms of Penicillin G |
|
Definition
combinations to extend halflife
Pen G Procaine or Pen G benzathine |
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|
Term
| Anti-pseudomonal use? MOA? examples? |
|
Definition
gram- bacteria, mainly pseudomonas aeruginosa (green toe infection)
structure allows access through pseudomonal bacteria that don't have porin structure
Carbenicillin, Piperacillin, Ticarcillin |
|
|
Term
| what are "suicidal inhibitors"? examples? |
|
Definition
B-lactamase inhibitors; have similar structure to B-Lactams, administered w/ B-lactams, bind to B-lactamase to inactivate and protect the B-lactam
Sublactam, Clavulonate, Tazobactam |
|
|
Term
| B-lactamase inhibitor administered with - ampicillin, amoxicillin, piperacillin, ticarcillin |
|
Definition
ampicillin + sublactam
amoxicillin + clavulonate
Piperacillin + tazobactam
Ticarcillin + clavulonate |
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|
Term
| cephalosporin similarities to penicillins |
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Definition
| structure/function, excretion, cross-allergenicity, resistance |
|
|
Term
| DOC for bacterial meningitis |
|
Definition
| 3rd generation cephalosporins, Ceftriaxone, Cefotaxime, Ceftazidime |
|
|
Term
| cephalosporins w/ NMTT side chain |
|
Definition
PMT
Cefoperazone
Cefamandole
Cefotetan |
|
|
Term
| unique side effects of NMTT cephalosporins |
|
Definition
- hypoprothrombinemia -> prolonged bleeding from inhibitions of Vitamin K depenedent factors
-disulfiram-like reaction (hangover symptoms) |
|
|
Term
| what B-lactams have the broadest spectrum? |
|
Definition
|
|
Term
| Imipenem, class? what is it commonly administered w/ and why? |
|
Definition
Carbapenem
Administered with cilastatin
Cilastatin inhibits renal dehydropeptidase I which normally cleaves Imipenem to an inactive metabolite that is nephrotoxic |
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|
Term
|
Definition
|
|
Term
| what are monobactams used for |
|
Definition
|
|
Term
|
Definition
| Vancomycin and Bacitracin |
|
|
Term
|
Definition
| block transpeptidation via binding to PBP, leads to weakening of cell wall, upon exposure to hypotonic environment causes cell swelling -> lysis |
|
|
Term
|
Definition
inhibition of transglycosylation
binds to D-ala-D-ala terminal end of Nam preventing binding to next Nam-Nag complex |
|
|
Term
|
Definition
| block transport of Nam-Nag precursors from cytoplasm to cell wall |
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|
Term
| Vancomycin, ADRs? mode of resistance? |
|
Definition
glycopeptide
Red man syndrome, Ototoxicity and Nephrotoxicity
Replacement of D-Ala with D-Lactate -> vancomycin cannot cap this end |
|
|
Term
|
Definition
glycopeptide
similar spectrum, less toxic and longer t1/2 version of Vancomycin
equally as efficacious in pseudomembranous colitis |
|
|
Term
|
Definition
cyclic lipopeptide
bacteriocidal
bind to membrane causing rapid depolarization, loss of membrane potential, inhibition of DNA, RNA and protein synthesis
used for Gram+ and complicated skin and skin structure infections (cSSSI) from S. Aureus bactermia |
|
|
Term
|
Definition
| Anti-pseudomonal penicillin |
|
|
Term
|
Definition
| Anti-pseudomonal, penicillin |
|
|
Term
|
Definition
| Oxipenicilin (anti-staph), penicillin |
|
|
Term
|
Definition
| Anti-pseudomonal, penicillin |
|
|
Term
|
Definition
Oxipenicillin (anti-staph), penicillin
*highly hepatotoxic, only used to determine if MRSA |
|
|
Term
| What makes MRSA resistant |
|
Definition
| additional PBP - PBP2A which has low affinity for most B-lactams, so bacteria will still produce a cell wall, just more slowly |
|
|
Term
| which generation cephalosporins, are more sensitive to lactamases? more specific to gram+, gram-? can cross BBB? |
|
Definition
1st generation
gram+ = 1st generation
gram- = 3rd generation
BBB = 3rd generation |
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|
Term
| which B-Lactams are renally excreted but not probenacid sensitive? |
|
Definition
| Carbapenems and Monobactams |
|
|
Term
| DOC for pseudomembranous colitis? alternative? |
|
Definition
DOC: Metroniazol
Alternative: Vancomycin |
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