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Antibiotics with novel mechanism of action discovered

October 23, 2019
University of Zurich
Many life-threatening bacteria are becoming increasingly resistant to existing antibiotics. Researchers have now discovered a new class of antibiotics with a unique spectrum of activity and mechanism of action - a major step in the fight against antimicrobial resistance. By disrupting outer membrane synthesis, the antibiotics effectively kill Gram-negative bacteria.

The rapid emergence of antimicrobial resistance is a matter of global concern. According to the World Health Organization (WHO), particularly Gram-negative bacteria like Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacteriaceae that are resistant to the carbapenem and cephalosporin antibiotics, pose a growing threat to human health. These pathogens can cause severe and often life-threatening infections. The last new class of antibiotics to reach the market against these microorganisms, the fluoroquinolones, dates back to the 1960s. Novel antibiotics with new mechanisms of action against Gram-negative bacteria are urgently needed, especially because resistance against the last resort antibiotic colistin is on a global rise.

Novel family of antibiotics against dangerous bacteria

Swiss research teams headed by the University of Zurich (UZH) and Polyphor AG now report the discovery and characterization of a new family of synthetic antibiotics that possess broad-spectrum anti-Gram-negative antimicrobial activity. "The new antibiotics interact with essential outer membrane proteins in Gram-negative bacteria," says John Robinson from the UZH Department of Chemistry, who co-headed the study. "According to our results, the antibiotics bind to complex fat-like substances called lipopolysaccharides and to BamA, an essential protein of the outer membrane of Gram-negative bacteria," Robinson adds.

Disruption of outer membrane synthesis via unexploited mechanism of action

BamA is the main component of the so-called ß-barrel folding complex (BAM), which is essential for outer membrane synthesis. After targeting this essential outer membrane protein, the antibiotics destroy the integrity of the bacterial membranes and the cells burst. The outer membrane of Gram-negative bacteria has the important function to protect the cells from toxic environmental factors, such as antibiotics. It is also responsible for the uptake and export of nutrients and signaling molecules. "Despite its critical importance, so far no clinical antibiotics target these key proteins required for outer membrane biogenesis," Robinson says.

Lead molecule in preclinical studies

The research was carried out in close collaboration with Polyphor AG, a former UZH start-up company that was founded in 1996. The clinical stage biopharmaceutical company based in Allschwil now plans to progress one compound into human clinical trials. "POL7306, a first lead molecule of the novel antibiotics class, is now in preclinical development," says Daniel Obrecht, chief scientific officer at Polyphor and co-head of the work.

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Materials provided by University of Zurich. Note: Content may be edited for style and length.

Journal Reference:

  1. Anatol Luther, Matthias Urfer, Michael Zahn, Maik Müller, Shuang-Yan Wang, Milon Mondal, Alessandra Vitale, Jean-Baptiste Hartmann, Timothy Sharpe, Fabio Lo Monte, Harsha Kocherla, Elizabeth Cline, Gabriella Pessi, Parthasarathi Rath, Seyed Majed Modaresi, Petra Chiquet, Sarah Stiegeler, Carolin Verbree, Tobias Remus, Michel Schmitt, Caroline Kolopp, Marie-Anne Westwood, Nicolas Desjonquères, Emile Brabet, Sophie Hell, Karen LePoupon, Annie Vermeulen, Régis Jaisson, Virginie Rithié, Grégory Upert, Alexander Lederer, Peter Zbinden, Achim Wach, Kerstin Moehle, Katja Zerbe, Hans H. Locher, Francesca Bernardini, Glenn E. Dale, Leo Eberl, Bernd Wollscheid, Sebastian Hiller, John A. Robinson, Daniel Obrecht. Chimeric peptidomimetic antibiotics against Gram-negative bacteria. Nature, 2019; DOI: 10.1038/s41586-019-1665-6

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University of Zurich. "Antibiotics with novel mechanism of action discovered." ScienceDaily. ScienceDaily, 23 October 2019. <>.
University of Zurich. (2019, October 23). Antibiotics with novel mechanism of action discovered. ScienceDaily. Retrieved April 13, 2024 from
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