TABLE 7.
Chromosomal or plasmid-encoded class C β-lactamases: mechanisms of acquired resistance to carbapenems
| Fold-increase MICsc |
Reference | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Bla or straina | Species | Locationb | Mechanisms | CAZ | FEP | IMP | ERT | MER | |
| MEV | E. coli | Chr | ESAC + OmpC decrease + OmpF loss | >128 | >16 | 8 | >16 | 8 | 368 |
| ACC-1 | E. coli | P | + OmpC/OmpF loss | >64 | 64 | 4 | >128 | 4 | 240 |
| ACT-1 | E. coli | P | + OmpC/OmpF loss | >256 | >16 | 128 | >512 | 32 | 240 |
| CMY-2 | E. coli | P | + OmpC/OmpF loss | >256 | >16 | 256 | >512 | 256 | 240 |
| DHA-1 | E. coli | P | + OmpC/OmpF loss | >512 | 64 | 16 | 256 | 8 | 240 |
| FOX-1 | E. coli | P | + OmpC/OmpF loss | >512 | >128 | 4 | >256 | 16 | 240 |
| CMY-2 | E. coli | P | Overproduction + OmpC/OmpF loss | >256 | >16 | >64 | >256 | >32 | 403 |
| CMY-2 | E. coli | P | Overproduction + OmpC insertion IS1 | >64 | >256 | 260 | |||
| CMY-2 | E. coli | P | Overproduction + OmpC/OmpF loss | >256 | >128 | >256 | >512 | 258 | |
| EC14 | E. coli | Chr | ESAC + OmpC/OmpF loss | >256 | >128 | 16 | >32 | 1 | 404 |
| CMY-4 | S. enterica | P | + OmpF loss | >512 | >64 | >16 | 405 | ||
| ACT-1 | K. pneumoniae | P | + Omp42-kDa loss | >128 | 8-32 | 8->16 | 322 | ||
| ACT-1 | K. pneumoniae | P | + OmpK35/36 insertion + PhoE decrease | 64-256 | 128 | 256 | 406 | ||
| DHA-1 | K. pneumoniae | P | + OmpK36 loss | >128 | >32 | >32 | 407 | ||
| DHA-1 | K. pneumoniae | P | + OmpK35/36 loss + AcrAB/OqxAB | 32 | >32 | 277 | |||
| ACC-1 | K. pneumoniae | P | + OmpK35/36 loss | >128 | 16 | 8 | 32 | 16 | 262 |
| FOX-1 | K. pneumoniae | P | + OmpK35/36 loss | >512 | 32 | 64 | 128 | 64 | 262 |
| MOX-1 | K. pneumoniae | P | + OmpK35/36 loss | 64 | 8 | 32 | 32 | 32 | 262 |
| EA-Z | K. aerogenes | Chr | + Omp40-kDa loss | 16 | 408 | ||||
| E15 | K. aerogenes | Chr | + OmpK35/36 loss | >256 | >16 | >16 | 409 | ||
| E11 | E. cloacae | Chr | Overproduction + OmpK35/36 loss | >256 | >16 | >16 | 409 | ||
| 144 | E. cloacae | Chr | Overproduction + porin loss | 64 | 16 | >128 | 410 | ||
| 213 | P. rettgeri | Chr | Overproduction + porin loss | 4 | 8 | >128 | 410 | ||
| ACT-28 | E. kobei | Chr | Overproduction + OmpC-like protein | >256 | >64 | >128 | >512 | >512 | 264 |
| A-1 | A. baumannii | Chr | Overproduction + Omp33/36 kDa decrease | 32 | >64 | 265 | |||
| A(4) or B(4) | A. baumannii | Chr | Overproduction + Omp37/44/47 kDa decrease | >32 | >32 | 8-16 | >16 | 411 | |
| Paeβ-04 | P. aeruginosa | Chr | Overproduction ESAC + mexB increase | 32 | 16 | 16 | 16 | 275 | |
| 3-D8 | P. aeruginosa | Chr | Overproduction + mexB increase + OprD loss + dacB | 128 | 64 | 32 | >256 | 273 | |
| AM339 | P. aeruginosa | Chr | Overproduction + mexA and mexC and mexX increase + OprD loss | >32 | >128 | >16 | >16 | >16 | 216 |
a
Strain names are underlined.
b
Chr, chromosome; P, plasmid.
c
CAZ, ceftazidime; FEP, cefepime; IMP, imipenem; ERT, ertapenem; MER, meropenem.