An article from Expert Review of Anti-Infective Therapy examines the emerging threats of resistant gram negative organisms and what we have now, or in the pipeline, to deal with them. In general there are few gram negative agents in late stages of development.
At present, Tygecycline is a consideration for Acinetobacter baumannii infections although its role is uncertain. A. baumannii frequently causes pulmonary infections. In that connection the recently reported failure of Tygecycline in the phase III HAP/VAP trial is concerning.