In vitro studies evaluating the activity of imipenem in combination with relebactam against Pseudomonas aeruginosa

Table 2 BLI concentration required to restore imipenem susceptibility in efflux proficient and deficient P. aeruginosa

Compound	Structure	BLI concentration to restore IMI (μg/mL)		Fold differential^b
Compound	Structure	MB6477 efflux-wt^a	MB6476 efflux-del^a	Fold differential^b
DABCO #1		> 100	12.5	> 8-fold
DABCO #2		50	3.125	16-fold
DABCO #3		12.5	6.25	2-fold
Relebactam		6.25	3.125	2-fold

BLI β-lactamase inhibitor, DABCO diazabicyclooctane, IMI imipenem
^aMB6477 nfxC, wild-type for other efflux pumps, spontaneous OprD deletion; MB6476 nfxC, Δ [MexAB-OprM] Δ [MexCD-OprJ] Δ [MexXY] Δ [MexJKL] Δ [MexHI-OpmD] Δ [OpmH])
^bDifferential between the concentrations required to restore susceptibility to imipenem at 4 μg/mL, expressed as the BLI concentration against MB6477 divided by the BLI concentration against MB6476

ISSN: 1471-2180