Large outbreak of infection and colonization with gram-negative pathogens carrying the metallo- beta -lactamase gene blaIMP-4 at a 320-bed tertiary hospital in Australia.

A large outbreak of infection and colonization with multiple genera of gram-negative bacilli carrying the metallo- beta -lactamase gene bla(IMP-4) occurred in a 36-bed intensive care unit at a tertiary hospital in Australia. The organisms emerged rapidly, caused severe infections, and contributed to mortality. Controlling the spread of these organisms remains a challenge for all staff involved.