TY - JOUR A1 - Hennessen, Fabienne A1 - Miethke, Marcus A1 - Zaburannyi, Nestor A1 - Loose, Maria A1 - Lukežič, Tadeja A1 - Bernecker, Steffen A1 - Hüttel, Stephan A1 - Jansen, Rolf A1 - Schmiedel, Judith A1 - Fritzenwanker, Moritz A1 - Imirzalioglu, Can A1 - Vogel, Jörg A1 - Westermann, Alexander J. A1 - Hesterkamp, Thomas A1 - Stadler, Marc A1 - Wagenlehner, Florian A1 - Petković, Hrvoje A1 - Herrmann, Jennifer A1 - Müller, Rolf T1 - Amidochelocardin overcomes resistance mechanisms exerted on tetracyclines and natural chelocardin JF - Antibiotics N2 - The reassessment of known but neglected natural compounds is a vital strategy for providing novel lead structures urgently needed to overcome antimicrobial resistance. Scaffolds with resistance-breaking properties represent the most promising candidates for a successful translation into future therapeutics. Our study focuses on chelocardin, a member of the atypical tetracyclines, and its bioengineered derivative amidochelocardin, both showing broad-spectrum antibacterial activity within the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) panel. Further lead development of chelocardins requires extensive biological and chemical profiling to achieve favorable pharmaceutical properties and efficacy. This study shows that both molecules possess resistance-breaking properties enabling the escape from most common tetracycline resistance mechanisms. Further, we show that these compounds are potent candidates for treatment of urinary tract infections due to their in vitro activity against a large panel of multidrug-resistant uropathogenic clinical isolates. In addition, the mechanism of resistance to natural chelocardin was identified as relying on efflux processes, both in the chelocardin producer Amycolatopsis sulphurea and in the pathogen Klebsiella pneumoniae. Resistance development in Klebsiella led primarily to mutations in ramR, causing increased expression of the acrAB-tolC efflux pump. Most importantly, amidochelocardin overcomes this resistance mechanism, revealing not only the improved activity profile but also superior resistance-breaking properties of this novel antibacterial compound. KW - chelocardins KW - atypical tetracyclines KW - broad-spectrum antibiotics KW - clinical isolates KW - uropathogens KW - urinary tract infection (UTI) KW - resistance-breaking properties KW - mechanism of resistance KW - AcrAB-TolC efflux pump Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213149 SN - 2079-6382 VL - 9 IS - 9 ER -