Acinetobacter baumannii is an organism that is an increasingly common cause of nosocomial pneumonia. It is a Gram negative bacillus when viewed microscopically after Gram’s stain. Although not particularly virulent it has become particularly troublesome because of its ability to cause outbreaks, particularly of extremely resistant strains. In many intensive care units, outbreak strains are susceptible only to tigecycline, colistin or polymyxin B. Some strains are resistant to all of these salvage options. Treatment of these strains presents an unmet medical need.