The spread and acquisition of NDM-1: a multifactorial problem.

bla NDM is a major mechanism of resistance of Gram-negative bacteria to β-lactam antibiotics including the carbapenems. bla NDM has been acquired by a large range of Gram-negative bacilli, especially by the Enterobacteriaceae and Acinetobacter spp. The combination of human factors (suboptimal antibiotic stewardship and infection control, movement of people between countries) plus bacterial factors (hospital adapted clones, environmental persistence and prolific horizontal gene transfer) have led to global spread of bla NDM at a rapid pace. Treatment options for New Delhi metallo-β-lactamase (NDM) producers are very limited. For serious infections, combination therapy including a polymyxin is preferred. However, resistance to polymyxins is emerging. Clearly, substantial international efforts must be made to control the spread of NDM producers or else many of the advances of modern medicine may be undermined by untreatable infections.