Burkholderia Lethal Factor 1BPSL1549, also suggested to be called Burkholderia lethal factor 1, is a protein of unknown function from Burkholderia pseudomallei, a causative agent of melioidosis (also called Whitmore's disease). This protein shows similarity to Escherichia coli cytotoxic necrotizing factor 1 which has been found to act as a potent cytotoxin against eukaryotic cells and is lethal when administered to mice. BPSL1549 expression levels correlate with suppression or promotion of pathogenic conditions. BPSL1549 inhibits helicase activity of translation initiation factor eIF4A. As yet, there is no vaccine and the organism is multidrug resistant.