"Multiplexed screen identifies a -specific small molecule targeting the outer membrane protein OprH and its interaction with LPS".

The surge of antimicrobial resistance threatens efficacy of current antibiotics, particularly against , a highly resistant gram-negative pathogen. The asymmetric outer membrane (OM) of combined with its array of efflux pumps provide a barrier to xenobiotic accumulation, thus making antibiotic discovery challenging. We adapted PROSPECT , a target-based, whole-cell screening strategy, to discover small molecule probes that kill mutants depleted for essential proteins localized at the OM. We identified BRD1401, a small molecule that has specific activity against a mutant depleted for the essential lipoprotein, OprL. Genetic and chemical biological studies identified that BRD1401 acts by targeting the OM β-barrel protein OprH to disrupt its interaction with LPS and increase membrane fluidity. Studies with BRD1401 also revealed an interaction between OprL and OprH, directly linking the OM with peptidoglycan. Thus, a whole-cell, multiplexed screen can identify species-specific chemical probes to reveal novel pathogen biology.