Organisms as well as pathogens require several transition metals including iron, copper, zinc, manganese, nickel and cobalt, for genetic replication and other cellular functions. Of these, iron is vital and plays a key role in DNA replication, transcription, synthesis of cofactors and other essential enzymes. During infection, iron deprivation, particularly sequestration thereof, represents a unique response against pathogen attack. The host sequesters ferrous (Fe