Rapidly emerging novel metallo beta lactamase--New Delhi metallo beta lactamase-1 (NDM-1)--is it a misnomer.

Metallo β-lactamases is the name given to certain enzymes found in gram negative bacteria belonging to Enter-obacteriaceae which confers resistance to all β-lactam antibiotics including carbapenems except monobactams. They belong to Ambler molecular class B and Bush-Jacoby-Medeiros Group 3.1,2 Resistance to carbapenems due to production of metallo β-lactamases in Gram Negative organisms is an increasing international public health problem. Escherichia coli and Klebsiella pneumoniae are the most common bacteria among the Enterobacteriaceae producing these enzymes developing multidrug resistance including β-lactam carbapenems like Imipenem, Meropenem, Doripenem and Ertapenem. These are the antibiotics in reserve used presently for the multidrug (fluoroquinolones, aminoglycosides and cephalosporins) resistance bacteria . But of late these bacteria have also been found producing metalo β-lactamases 3 and have become resistant to even this group of antibiotics and are referred to as superbugs because of their killer potential .