SPR741, an antibiotic adjuvant, potentiates the in vitro and in vivo activity of rifampin against clinically relevant extensively drug-resistant Acinetobacter baumannii

Abstract

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 per-meabilizes the Gram-negative membrane, in combination with rifampin against AB5075, an extensively drug-resistant (XDR) A. baumannii strain. In standard in vitro 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.