Against antibiotic resistance, bacteria fishing

16.07.2025 – 08:00

Swiss National Fund / Fund National Suisse

Bern (ots)

Identifying certain bacteria quickly makes it possible to optimize antibiotic treatments. Meanwhile, With the support of the FNS. For example, a team from the University of Zurich has developed molecules to recognize and capture certain species.

The discovery of antibiotics revolutionized medicine in the 20th century and saved many human lives. Furthermore, But the appearance of resistant bacteria quickly established itself as a new challenge. Nevertheless, One of the keys in the fight against this scourge is the precise identification of bacteria during an infection. Moreover, It makes it possible to use targeted and effective antibiotics, which reduces the risk of the emergence of new resistance.

With the support of the Swiss National Fund (FNS). Moreover, scientists have developed molecules to recognize certain bacteria faster than until against antibiotic resistance, bacteria fishing now. For example, Their research has just been published in the journal Communications Biology

. Meanwhile, They open the way for accelerated methods of medical diagnostics, especially in the event of blood infection, but not only. Therefore, “The developed molecules are already used in a partnership with the Zurich Start-up Rqmicro. Similarly, which develops tools for water quality monitoring”, rejoices Markus Seeger, a biochemist who conducted this study at the Institute of Medical Microbiology at the University of Zurich.

Accelerate the speed of certain diagnoses

“In the race between the bacterial evolution of antibiotic -resistance. However, the development of new antibiotics, we have no chance, says the researcher. Furthermore, Bacteria has been at war with viruses for several million years and are used to evolving to escape new dangers.” The only current solution is a meticulous use of antibiotics. Nevertheless, It prevents bacteria from being constantly confronted with residues. In addition, traces of against antibiotic resistance, bacteria fishing antibiotics in their environment, so that they succumb when they are exposed during treatments. In addition, This strategy requires as fast and precise medical diagnostics as possible.

However, traditional identification methods take time. Additionally, In addition, They consist in taking bacteria from patients. Furthermore, then growing them so that their number becomes sufficient to carry out detailed analyzes. For example, The growth phase lasts approximately 12 hours for certain species, sometimes longer for others. Nevertheless, The analyzes add two overtime hours.

Markus Seeger. his team seek to accelerate the procedure: “Our idea is to identify certain bacteria earlier, even in small quantities, by coloring them specifically. And we try to capture them directly in the blood to be able to increase their density. analyze them faster.” This approach is not an exhaustive diagnosis. But it confirms or not the presence of certain specific bacteria faster than with traditional methods. A saving of against antibiotic resistance, bacteria fishing precious time especially in the event of blood infections. where it is not always possible to wait for the one or two days necessary for detailed analyzes.

His group looked at the recognition of the bacteria Escherichia coli. The latter is often involved in urinary tract infections and can also be responsible for blood infections. And it is a bacterial species in which resistance rates increased between 2004. 2024 in Switzerland, going as far as fivefold for certain classes of antibiotics. “Knowing whether it is Escherichia coli. something else is already a very good indication for making a first decision as to the treatment to be administered,” said the biochemist. In this case. the tools developed by his team would allow to win about six hours on the dozen that traditional diagnoses take.

Penetrate the “jungle of sugars”

To go fishing in Escherichia coli. Markus Seeger and his team had to solve two against antibiotic resistance, bacteria fishing problems. On the one hand. it was necessary to find the right bait: a specific element and common to all the Escherichia coli bacteria. On the other hand. the researcher admits having “underestimated the complexity of the jungle of sugars which form a wall around the bacteria”. A jungle so dense that few molecules pass through.

As a hook, scientists have therefore opted for miniature antibodies, called nanobodies. With their small size, they can pass without problems between the branches of sugars. They are also more stable than conventional antibodies and thus remain functional longer at room temperature. A key element to obtain storable and transportable detection tools without having to worry about the cold chain. The team has traveled an international database and another register of bacteria detected in hospital in Switzerland. By analyzing the genome of the Escherichia coli type bacteria. it identified a protein – OMPA – of against antibiotic resistance, bacteria fishing which is found exclusively in Escherichia coli. The group then developed nanobodies capable of recognizing this version of OMPA in a specific. effective way in more than 90% of the members of the species. So a hook that specifically baits the Escherichia coli bacteria.

A ready -to -use solution to color the bacteria. but not to fish them: “To identify Escherichia coli, it works well. We can attach very small molecules of dyes to nanobodies without significantly increasing their size, explains the researcher. On the other hand, for the capture of bacteria, we use larger magnetic balls. Bacteria. “The scientists then created a real fishing rod for their detection kit: a molecular wire was developed to connect. nanobodies – the hook – with magnetic balls blocked by sugars – the handle. “We now have a tool that allows you to recognize Escherichia coli and capture it. I hope to succeed against antibiotic resistance, bacteria fishing in implementing it in clinical diagnostics. We already use it for environmental analyzes,” concludes the biochemist.

M. Sorgenfrei et al.: Rapid detection and capture of clinical Escherichia coli strains mediated by OmpA-targeting nanobodies. Communications Biology (2025).

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National Research Program “The Resistance to Antimicrobials” (PNR 72)

The problem of antibiotic resistance is increasingly pressing. It is to reply that the Swiss National Fund for Scientific Research (FNS). mandated in 2015 by the Federal Council, launched the National Research Program “La Résistance des Antimicrobiens” (PNR 72). He was planned in coordination with the National Antibioressenter (Star) strategy.

As part of this program. 45 projects were carried out: 33 in Swiss universities and high schools, as well as 12 international projects relating to the joint European programming initiative on antimicrobial resistance (JPIAMR). PNR 72 has a financial envelope of 20 million francs.

He gathered doctors, veterinarians, biologists and environmental experts collaborating in an interdisciplinary manner. These scientists against antibiotic resistance, bacteria fishing have explored new approaches to slow down the spread of antibiotic resistant bacteria and improve forms of treatment.

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The text of this press release and more information is available on the website of the Swiss National Fund.
Contact:
Markus Seeger
Medical Microbiology Institute
University of Zurich
28/30 preferred veneriastras
CH-8006 Zurich