Antibiotic potentiation and inhibition of cross-resistance in pathogens associated with cystic fibrosis

Abstract

Critical Gram-negative pathogens, like Pseudomonas, Stenotrophomonas and Burkholderia, have become resistant to most antibiotics. Complex resistance profiles together with synergistic interactions between these organisms increase the likelihood of treatment failure in distinct infection settings, for example in the lungs of cystic fibrosis patients. Here, we discover that cell envelope protein homeostasis pathways underpin both antibiotic resistance and cross-protection in CF-associated bacteria. We find that inhibition of oxidative protein folding inactivates multiple species-specific resistance proteins. Using this strategy, we sensitize multi-drug resistant Pseudomonas aeruginosa to β-lactam antibiotics and demonstrate promise of new treatment avenues for the recalcitrant pathogen Stenotrophomonas maltophilia. The same approach also inhibits cross-protection between resistant S. maltophilia and susceptible P. aeruginosa, allowing eradication of both commonly co-occurring CF-associated organisms. Our results provide the basis for the development of next-generation strategies that target antibiotic resistance, while also impairing specific interbacterial interactions that enhance the severity of polymicrobial infections.

Development of a sensor for disulfide bond formation in diverse bacteria

“…Considering that disulfide bonds are required for the stability of virulence factors, toxins, antibiotic resistance, and cell envelope biogenesis proteins, lack of disulfide bond formation in many gram-negative pathogens results in virulence attenuation as well as antibiotic and phage susceptibility (6, 7, 21, 23, 45). However, the pathway is not essential for aerobic laboratory growth (17), thus facilitating the development of methods to search for molecules that identify molecules on-target in pathogenic bacteria, also known as target-based and whole cell-based approaches (46).…”

“…Overall, disulfide bond formation is required for virulence but not for in vitro growth of gram-negative bacteria (6, 7), whereas it is essential in actinobacteria (18–20). Disulfide bond-forming enzymes represent a compelling new drug target because their inhibition could simultaneously affect several proteins localized in the cell envelope, including virulence factors, proteins involved in outer membrane biogenesis, cell division, and antibiotic resistance (6, 7, 21–23). Thus, we have previously developed a cell-based and target-based assay to find molecules that inhibit the membrane proteins, DsbB and VKOR, of pathogenic bacteria (24, 25).…”

Warfarin analogs target disulfide bond-forming enzymes and suggest a residue important for quinone and coumarin binding

“…DSB formation is a fundamental aspect of protein folding in both eukaryotes and prokaryotes. In bacteria, DSBs play critical roles in the folding and stability of proteins involved in important cellular processes, including cell division, outer membrane biogenesis, virulence, and antibiotic resistance 1–4 . Hence, DSB-forming enzymes represent a new drug target simultaneously affecting several proteins localized in the cell envelope.…”

Warfarin analogs target disulfide bond-forming enzymes and suggest a residue important for quinone and coumarin binding

“…DSB formation is a fundamental aspect of protein folding in both eukaryotes and prokaryotes. In bacteria, DSBs play critical roles in the folding and stability of proteins involved in important cellular processes, including cell division, outer membrane biogenesis, virulence, and antibiotic resistance ( 1 , 2 , 3 , 4 ). Hence, DSB-forming enzymes represent a new drug target simultaneously affecting several proteins localized in the cell envelope.…”