RavA-ViaA antibiotic response is linked to Cpx and Zra2 envelope stress systems in .

The RavA-ViaA complex was previously found to sensitize to aminoglycosides (AGs) in anaerobic conditions, but the mechanism is unknown. AGs are antibiotics known for their high efficiency against Gram-negative bacteria. In order to elucidate how the expression of the genes increases bacterial susceptibility to aminoglycosides, we aimed at identifying partner functions necessary for increased tolerance in the absence of RavA-ViaA, in . We show that membrane stress response systems Cpx and Zra2 are required in the absence of RavA-ViaA, for the tolerance to AGs and for outer membrane integrity. In the absence of these systems, the strain's membrane becomes permeable to external agents such as the antibiotic vancomycin.