SPR741, an Antibiotic Adjuvant, Potentiates the and Activity of Rifampin against Clinically Relevant Extensively Drug-Resistant Acinetobacter baumannii.

is responsible for 10% of all nosocomial infections and has >50% mortality rates when causing ventilator-associated pneumonia. In this proof-of-concept study, we evaluated SPR741, an antibiotic adjuvant that permeabilizes the Gram-negative membrane, in combination with rifampin against AB5075, an extensively drug-resistant (XDR) strain. In standard assays and in a murine pulmonary model, we found that this drug combination can significantly reduce bacterial burden and promote animal survival despite an aggressive infection.