1-((2,4-Dichlorophenethyl)Amino)-3-Phenoxypropan-2-ol Kills Pseudomonas aeruginosa through Extensive Membrane Damage

Abstract

The ever increasing multidrug-resistance of clinically important pathogens and the lack of novel antibiotics have resulted in a true antibiotic crisis where many antibiotics are no longer effective. Further complicating the treatment of bacterial infections are antibiotic-tolerant persister cells. Besides being responsible for the recalcitrant nature of chronic infections, persister cells greatly contribute to the observed antibiotic tolerance in biofilms and even facilitate the emergence of antibiotic resistance. Evidently, eradication of these persister cells could greatly improve patient outcomes and targeting persistence may provide an alternative approach in combatting chronic infections. We recently characterized 1-((2,4-dichlorophenethyl)amino)-3-phenoxypropan-2-ol (SPI009), a novel anti-persister molecule capable of directly killing persisters from both Gram-negative and Gram-positive pathogens. SPI009 potentiates antibiotic activity in several in vitro and in vivo infection models and possesses promising anti-biofilm activity. Strikingly, SPI009 restores antibiotic sensitivity even in resistant strains. In this study, we investigated the mode of action of this novel compound using several parallel approaches. Genetic analyses and a macromolecular synthesis assays suggest that SPI009 acts by causing extensive membrane damage. This hypothesis was confirmed by liposome leakage assay and membrane permeability studies, demonstrating that SPI009 rapidly impairs the bacterial outer and inner membranes. Evaluation of SPI009-resistant mutants, which only could be generated under severe selection pressure, suggested a possible role for the MexCD-OprJ efflux pump. Overall, our results demonstrate the extensive membrane-damaging activity of SPI009 and confirm its clinical potential in the development of novel anti-persister therapies.

Bacterial Heterogeneity and Antibiotic Survival: Understanding and Combatting Persistence and Heteroresistance

“…Directly targeting the cell envelope of bacteria is also an underexploited strategy (Hurdle et al, 2011). Membrane-active agents, such as cationic antimicrobial peptides (Bahar et al, 2015) and small molecules (Defraine et al, 2018b;Liebens et al, 2017), compromise functioning of the inner and outer membrane, thereby efficiently killing persisters of Grampositive and Gram-negative species in vitro and in vivo. Using an automated high-throughput C. elegans methicillin-resistant S. aureus (MRSA) killing assay, synthetic retinoid molecules were identified in a library screen of small synthetic molecules (Kim et al, 2018).…”

“…Importantly, such anti-persister, membrane-targeting strategies should be selective for bacterial membranes only and should not interfere with the eukaryotic plasma membrane. Although challenging, several selective membrane-targeting compounds with high anti-bacterial activity and low cytotoxicity have been described (Defraine et al, 2018b;Kim et al, 2018;Liebens et al, 2017). Moreover, these compounds can be optimized to further decrease cytotoxicity (Kim et al, 2018), indicating that targeting the membrane is indeed a viable anti-persister strategy.…”

Brevinin-2GHk from Sylvirana guentheri and the Design of Truncated Analogs Exhibiting the Enhancement of Antimicrobial Activity

“…Outer membrane permeability assay was carried out as before [36]. Briefly, P. aeruginosa (ATCC 27853) was used and cultured in LB medium.…”

Longitudinal variations in the gastrointestinal microbiome of the white shrimp, Litopenaeus vannamei

“…A possible explanation of this networking is that these could compete for nutrient resources or adhesion sites, displacing the order Vibrionales. Besides, the order Costridales is a Gram-positive butyric acid-producing probiotic, Clostridium butyricum , which is also described as part of the normal intestine microbiota of shrimp and has a beneficial effect on the intestine health of L. vannamei ( Duan et al, 2018 ). Also, the order Rhizobiales has already been reported to exert an antagonistic effect against Vibrionales in postlarval shrimp ( L. vannamei ) ( Cao et al, 2020 ).…”