Table 2: Beta lactamases classifications, ESBL activity and representative enzymes.

Molecular Class Functional Group ESBL Activityc Representative Enzymes
A 2a N PC1
2b N TEM-1, SHV-1
2be Y CTX-M-14, -15
2br N TEM-30, SHV-10
2ber Y TEM-50, TEM-121
2c N PSE-4, CARB-3
2ce Ne RTG-4
2e Y SFO-1, FEC-1, L2
2f Y KPC-2, SME-1f
B 3ag Y IMP, VIM, NDM, L1
3b N CphA
C 1 N AmpC, ACT-1
1e Y GC1, CMY-37
D 2d N OXA-1, OXA-10
2de V OXA-11, OXA-15
2df Y OXA-23, OXA-48

Adapted and modified from Bush [68].c= Based on hydrolysis of cefotaxime, ceftazidime, or cefepime. e= In spite of kcat values generally B1 s-1, resistance to cefepime and cefpirome is seen in producing organisms. g= Includes subclasses B1 and B3. Y= kcat >5 s-1, N= kcat <5 s-1, V= variable within the functional group.

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