Exploration of BAY 11-7082 as a novel antibiotic

Exposure of the Gram-negative pathogen Pseudomonas aeruginosa to sub-inhibitory concentrations of antibiotics increases formation of biofilms. We exploited this phenotype to identify molecules with potential antimicrobial activity in a biofilm-based high-throughput screen. The anti-inflammatory compound BAY 11-7082 induced dose-dependent biofilm stimulation, indicative of antibacterial activity. We confirmed that BAY 11-7082 inhibits growth of P. aeruginosa and other priority pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). We synthesized 27 structural analogues, including a series based on the related scaffold 3-(phenylsulfonyl)-2-pyrazinecarbonitrile (PSPC), 10 of which displayed increased anti- Staphylococcal activity. Because the parent molecule inhibits the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome, we measured the ability of select analogues to reduce IL-1β production in mammalian macrophages, identifying minor differences in the structure-activity relationship for the anti-inflammatory and antibacterial properties of this scaffold. Although we could evolve stably resistant MRSA mutants with cross resistance to BAY 11-7082 and PSPC, their lack of shared mutations suggested that the two molecules could have multiple targets. Finally, we showed that BAY 11-7082 and its analogues potentiate the activity of penicillin G against MRSA, suggesting that this scaffold may serve as an interesting starting point for the development of antibiotic adjuvants. ![Figure][1] ### Competing Interest Statement The authors have declared no competing interest. * ARP : Antibiotic Resistance Platform; CCCP : carbonyl cyanide m-chlorophenyl hydrazine; DiSC3(5) : 3,3’-dipropylthiadicarbocyanine iodide; FICI : fractional inhibitory concentration index; LB : lysogeny broth; MHA : Mueller-Hinton agar; MHB : Mueller-Hinton broth; PMF : proton motive force; PSPC : 3-(phenylsulfonyl)-2-pyrazinecarbonitrile; PTP : protein tyrosine phosphatase; TAT : twin arginine translocase [1]: pending:yes