Kinetic characterization of VIM-7, a divergent member of the VIM metallo-beta-lactamase family.

Purified recombinant VIM-7 possesses efficient penicillinase and carbapenemase activities comparable to those of VIM-2. Cephalosporinase activity was variable and generally lower than those of VIM-1 and VIM-2. A homology model suggests that the VIM-7 Tyr-218 Phe substitution may be responsible for the reduced catalytic efficiency against certain cephalosporins, including ceftazidime and cefepime.