Β-lactamases: Difference between revisions
From IDWiki
Β-lactamases
(→) |
(→) |
||
Line 6: | Line 6: | ||
== Classification == |
== Classification == |
||
+ | * Classes A, B, and C: serine β-lactamases |
||
− | * '''Class A''' |
||
+ | ** '''Class A''': inhibited by clavulanic acid or tazobactam |
||
− | ** Constitutively expressed plasmid |
+ | *** Constitutively expressed plasmid |
− | ** Most common ESBL in Gram-negative bacteria |
+ | *** Most common ESBL in Gram-negative bacteria |
− | ** Resistance to 2nd and 3rd generation cephalosporins |
+ | *** Resistance to 2nd and 3rd generation cephalosporins |
− | ** Examples include penicillinase, TEM-1 (common in GNBs), CTX-M, ''K. pneumoniae'' carbapenemase (KPC) family |
+ | *** Examples include penicillinase, TEM-1 (common in GNBs), CTX-M, ''K. pneumoniae'' carbapenemase (KPC) family |
− | ** Common in ''[[E. coli]]'', ''[[Klebsiella]]'', and ''[[Proteus]]'' spp. |
+ | *** Common in ''[[E. coli]]'', ''[[Klebsiella]]'', and ''[[Proteus]]'' spp. |
− | * '''Class B''': metallobetalactamases |
||
+ | ** '''Class C''': not inhibited by clavulanic acid or EDTA, resistant to cefoxitin, inhibited by clox in vitro |
||
+ | *** AmpC = chromosomal |
||
⚫ | |||
⚫ | |||
+ | ** '''Class D''': not inhibited by EDTA, variably inhibited by clavulanic acid; hard to identify |
||
⚫ | |||
+ | * '''Class B''': metallo-β-lactamase, inhibited by EDTA, not inhibited by clavulanic acid |
||
** Examples include New Delhi metallo-beta-lactamase (NDM-1) |
** Examples include New Delhi metallo-beta-lactamase (NDM-1) |
||
− | * '''Class C''': ampC |
||
⚫ | |||
⚫ | |||
− | * '''Class D''': OXA |
||
⚫ | |||
== Management == |
== Management == |
Revision as of 20:27, 1 February 2020
Definition
- Bacteria containing a plasmid that codes for an extended-spectrum beta-lactamase (ESBL)
- Most common with Escherichia coli and Klebsiella
Classification
- Classes A, B, and C: serine β-lactamases
- Class A: inhibited by clavulanic acid or tazobactam
- Constitutively expressed plasmid
- Most common ESBL in Gram-negative bacteria
- Resistance to 2nd and 3rd generation cephalosporins
- Examples include penicillinase, TEM-1 (common in GNBs), CTX-M, K. pneumoniae carbapenemase (KPC) family
- Common in E. coli, Klebsiella, and Proteus spp.
- Class C: not inhibited by clavulanic acid or EDTA, resistant to cefoxitin, inhibited by clox in vitro
- AmpC = chromosomal
- Often an inducible AmpC gene present in the genome
- Common in Citrobacter, Serratia, and Enterobacter
- Class D: not inhibited by EDTA, variably inhibited by clavulanic acid; hard to identify
- Common in Acinetobacter
- Class A: inhibited by clavulanic acid or tazobactam
- Class B: metallo-β-lactamase, inhibited by EDTA, not inhibited by clavulanic acid
- Examples include New Delhi metallo-beta-lactamase (NDM-1)
Management
- Antibiotic therapy tailored to the resistance pattern
- Carbapenems, aminoglycosides, fluoroquinolones, and Septra typically work well