Β-lactam resistance: Difference between revisions
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Β-lactam resistance
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+ | {{DISPLAYTITLE:β-lactam resistance}} |
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+ | ===β-lactamases=== |
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− | * Class A: original active-site serine ß-lactamases |
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− | * Class B: original metallo-ß-lactamases |
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− | * Class D: OXA ß-lactamases |
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− | + | *Also see [[Β-lactamases]] |
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− | === NDM-1 === |
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− | * Can be treated empirically with [[ceftazidime-avibactam]] and [[aztreonam]] +/- [[colistin]] |
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+ | {| class="wikitable" |
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+ | !Class |
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+ | !Binding Site |
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+ | !Examples |
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+ | !Inhibitors |
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+ | |- |
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+ | |A |
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+ | |serine |
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+ | |TEM, SHV, KPC, CTX-M, GES |
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+ | |avibactam, vaborbactam, relebactam |
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+ | |- |
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+ | |B |
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+ | |metallo |
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+ | |VIM, NDM, IMP |
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+ | | |
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+ | |- |
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+ | |C |
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+ | |serine |
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+ | |AmpC, P99 |
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+ | |avibactam, vaborbactam, relebactam |
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+ | |- |
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+ | |D |
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+ | |serine |
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+ | |OXA (oxacillinase) enzymes |
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+ | |avibactam (OXA-48) |
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+ | |} |
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+ | *TEM-1: most common β-lactamase in Gram-negative bacteria |
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+ | *KPC: most common carbapenemase |
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+ | *OXA-48: most common carbapenemase in [[Acinetobacter]] |
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+ | ===Efflux Pumps=== |
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+ | *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 |
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+ | ===Porin Loss=== |
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+ | *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]] |
Latest revision as of 12:10, 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