Β-lactam resistance: Difference between revisions
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Β-lactam resistance
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*Porin channel mutations that reduce antibiotic influx |
*Porin channel mutations that reduce antibiotic influx |
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==β-lactamases== |
===β-lactamases=== |
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*Also see [[Β-lactamases]] |
*Also see [[Β-lactamases]] |
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===Ambler Classification of ß-lactamases=== |
====Ambler Classification of ß-lactamases==== |
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*Based on amino acid sequences rather than function |
*Based on amino acid sequences rather than function |
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===Specific ß-lactamases=== |
====Specific ß-lactamases==== |
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*TEM-1: most common β-lactamase in Gram-negative bacteria |
*TEM-1: most common β-lactamase in Gram-negative bacteria |
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*OXA-48: most common carbapenemase in [[Acinetobacter]] |
*OXA-48: most common carbapenemase in [[Acinetobacter]] |
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==Efflux Pumps== |
===Efflux Pumps=== |
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*Major cause of resistance in [[Pseudomonas aeruginosa]] and similar species |
*Major cause of resistance in [[Pseudomonas aeruginosa]] and similar species |
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*e.g. MexAB-OprM, which confers broad antimicrobial resistance including cephalosporins and some carbapanems |
*e.g. MexAB-OprM, which confers broad antimicrobial resistance including cephalosporins and some carbapanems |
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==Porin Loss== |
===Porin Loss=== |
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*Most common cause of carbapenem resistance in [[Pseudomonas aeruginosa]] |
*Most common cause of carbapenem resistance in [[Pseudomonas aeruginosa]] |
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== Management == |
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* See also [[Carbapenem-resistant organisms]] |
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[[Category:Antibiotics]] |
[[Category:Antibiotics]] |
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Latest revision as of 16:10, 2 April 2022
Mechanisms
- ß-lactamase production: enzymatic breakdown of beta lactam antibiotic
- Penicillin binding protein mutations (e.g. MRSA)
- Efflux pump mutations
- Porin channel mutations that reduce antibiotic influx
β-lactamases
- Also see β-lactamases
Ambler Classification of ß-lactamases
- Based on amino acid sequences rather than function
- Classes A, C, and D are serine ß-lactamases, while class B are metallo-β-lactamases
| Class | Binding Site | Examples | Inhibitors |
|---|---|---|---|
| A | serine | TEM, SHV, KPC, CTX-M, GES | avibactam, vaborbactam, relebactam |
| B | metallo | VIM, NDM, IMP | |
| C | serine | AmpC, P99 | avibactam, vaborbactam, relebactam |
| D | serine | OXA (oxacillinase) enzymes | avibactam (OXA-48) |
Specific ß-lactamases
- TEM-1: most common β-lactamase in Gram-negative bacteria
- KPC: most common carbapenemase
- NDM-1: broad-spectrum metallo-β-lactamase and carbapenemase
- OXA-48: most common carbapenemase in Acinetobacter
Efflux Pumps
- Major cause of resistance in Pseudomonas aeruginosa and similar species
- e.g. MexAB-OprM, which confers broad antimicrobial resistance including cephalosporins and some carbapanems
Porin Loss
- Most common cause of carbapenem resistance in Pseudomonas aeruginosa
Management
- See also Carbapenem-resistant organisms
