Fig 2.

Contributions of CME and MBLs (BlaB and GOB) to resistance. (a) Disks containing imipenem (IMI), ceftazidime (CAZ), and the inhibitors dipicolinic acid (DPA) (for MBLs) and clavulanic acid (CLA) (for CME), applied to an E. meningoseptica culture. (b) Crude extract activity against cefotaxime, ceftazidime, nitrocefin, and imipenem with and without preincubation with EDTA [EDTA and DPA chelate Zn(II) ions, which are essential for MBL activity). Initial rates of hydrolysis were measured at 30°C in PBS medium. Antibiotic and EDTA concentrations were 300 μM and 25 mM, respectively. (c) Anti-GOB and anti-BlaB Western blots of immunoprecipitates and supernatants. (d) Carbapenemase activity of supernatants before and after removal of GOB and BlaB. IP, immunoprecipitate; SN, supernatant; pIS, treated with preimmune serum; aS, treated with antiserum.