Table 1 Classification schemes for bacterial β-lactamases.
Bush-Jacoby group (2009) | Molecular class (subclass) | Distinctive substrate(s) | Defining characteristic(s) | Representative enzyme(s) |
|---|---|---|---|---|
1 | C | Cephalosporins | Greater hydrolysis of cephalosporins than benzylpenicillin; hydrolyzes cephamycins | E. coli AmpC, P99, ACT-1, CMY-2, FOX-1, MIR-1 |
1e | C | Cephalosporins | Increased hydrolysis of ceftazidime and often other oxyimino-β-lactams | GC1, CMY-37 |
2a | A | Penicillins | Greater hydrolysis of benzylpenicillin than cephalosporins | PC1 |
2b | A | Penicillins, early | Similar hydrolysis of benzylpenicillin and cephalosporins | TEM-1, TEM-2, SHV-1 |
| Â | Â | cephalosporins | Â | Â |
2be | A | Extended-spectrum | Increased hydrolysis of oxyimino-β-lactams (cefotaxime, | TEM-3, SHV-2, CTX-M-15, PER-1, |
| Â | Â | cephalosporins, monobactams | ceftazidime, ceftriaxone, cefepime, aztreonam) | VEB-1 |
2br | A | Penicillins | Resistance to clavulanic acid, sulbactam, and tazobactam | TEM-30, SHV-10 |
2ber | A | Extended-spectrum | Increased hydrolysis of oxyimino-β-lactams combined with | TEM-50 |
| Â | Â | cephalosporins, monobactams | resistance to clavulanic acid, sulbactam, and tazobactam | Â |
2c | A | Carbenicillin | Increased hydrolysis of carbenicillin | PSE-1, CARB-3 |
2ce | A | Carbenicillin, cefepime | Increased hydrolysis of carbenicillin, cefepime, and cefpirome | RTG-4 |
2d | D | Cloxacillin | Increased hydrolysis of cloxacillin or oxacillin | OXA-1, OXA-10 |
2de | D | Extended-spectrum cephalosporins | Hydrolyzes cloxacillin or oxacillin and oxyimino-β-lactams | OXA-11, OXA-15 |
2df | D | Carbapenems | Hydrolyzes cloxacillin or oxacillin and carbapenems | OXA-23, OXA-48 |
2e | A | Extended-spectrum cephalosporins | Hydrolyzes cephalosporins. Inhibited by clavulanic acid but not aztreonam | CepA |
2f | A | Carbapenems | Increased hydrolysis of carbapenems, oxyimino-β-lactams, cephamycins | KPC-2, IMI-1, SME-1 |
3a | B (B1) | Carbapenems | Broad-spectrum hydrolysis including carbapenems but not monobactams | IMP-1, VIM-1, CcrA, IND-1 |
| Â | B (B3) | Â | Â | L1, CAU-1, GOB-1, FEZ-1 |
3b | B (B2) | Carbapenems | Preferential hydrolysis of carbapenems | CphA, Sfh-1 |
NI | Unknown | Â | Â | Â |