Science – Virus vs. bacteria: Phage therapy for patients – Wikipedia

BERLIN (dpa) – Some people may find it dangerous to rub viruses into wounds, inhale them, swallow them or even inject them into the bloodstream. But in the so-called phage therapy, viruses that feed on bacteria and that are harmless to humans are used.

With the increasing number of antibiotic resistances, this form of treatment, which has not been used for a long time, is getting more attention once again. But is it the solution to the major medical crisis? Two major German projects are about to treat patients.

Germs are constantly around and inside us. An adult human is made up of about 30 trillion body cells, 40 trillion bacteria – and 300 trillion phages, says phage therapy expert Christian Wylie, director of the trauma surgery clinic at Bundeswehr Hospital in Berlin. Phages are viruses that initiate reproductive programs in bacteria until the mass of newly produced viruses causes the bacterial cell to explode. Thus bacterial accumulations, in the focus of inflammation for example, can quickly disappear.

looming teacher

One of the projects where patients will soon be treated is Phage4Cure, where an inhaled sterilizer is being developed against the feared hospital germ, Pseudomonas aeruginosa. The pathogen often colonizes the lungs of cystic fibrosis patients. The first clinical phase of the study on basic tolerance will begin in late summer, says Christine Rode at the Leibniz Institute DSMZ (German Microorganisms and Cell Cultures Group GmbH) in Braunschweig. Contrary to what usually happens, there is also a direct group with patients. “If the first stage is successful and patients feel better, a real milestone in phage treatment will be reached in Germany.”

A small number of patients are already being treated in Germany, but the approved treatments available to them are ineffective. For example, from Christian Kühn, Head of the National Phage Center at Hannover Medical School. “Every day I see what antibiotic resistance is doing,” the doctor asserts. “We need alternatives.” More than 30 patients in Hanover have already been treated, often against Staphylococcus aureus, a bacterium that can cause stubborn wound infections.

The second German project, the “PhagoFlow” project implemented by the Trauma Surgery Clinic at the Bundeswehr Hospital in Berlin, is also based on individual production used for each individual patient – known as the magistral app. Whereas “Phago4Cure” is about a clinical picture, pathogen, and managed mixture, “PhagoFlow” aims to address different clinical images caused by different pathogens, explains project manager Willie. He hopes that from the second half of the year, the first patients can be cured.

It is known as penicillin

Phages have been used to fight infection for nearly a century. They were discovered ten years before Scottish bacteriologist Alexander Fleming discovered the effect of the antibiotic penicillin in 1928.

Big difference between the two bactericidal killers: While antibiotics act as a weapon of mass destruction, phages are contractual killers with a very specific target. They infect only one type of bacteria, and often only one specific strain of that species, which makes their use complex: first, the appropriate phage must be found for the patient’s specific bacterial strain. “Usually more than one strain plays a role in a critical infection,” explains Holger Zeehr, chair of the division of pharmaceutical biotechnology at the Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM).

But where can you find the right phages to combat specific pathogens? Experts often choose a very simple source for this: “wastewater,” says phage researcher Alexander Harms of Biozentrum at the University of Basel. First, bacteria that are used against phages are grown on feeder plates. The water sample comes on the bacterial lawn. If a bactericidal phage is present, a hole is created in the bacterial lawn – the virus is isolated from this spot and multiplies in the laboratory.

A substitute for antibiotics

Much more effort than pulling a pill that works against many pathogens from a tray. But the wonder weapon of antibiotics is in danger of becoming dull. It is estimated that more than 30,000 deaths in the European Union are caused by antibiotic-resistant bacteria each year. According to estimates, there are about 700,000 worldwide. upward trend. Can phage therapy help?

In Eastern Bloc countries – where antibiotics were initially not widely accessed – phages continued to be used frequently. To this day, institutions from these countries are world leaders, most notably the Georgi Eleva Institute in Tbilisi, Georgia. Other countries such as the USA, Belgium and France are now reviving this type of treatment. Examples from the USA indicate that it is now possible to create an appropriate phage therapy for a patient within 10 days, says Christian Kuhn of the Hannover Phage Center.

Convincing results about the efficacy of phages in very large clinical studies, since they have become the standard in drug research, are not yet available for bacteriophages that can often only be used individually, says phage expert Christine Rohde. Individual case reports and smaller studies show impressive success, German experts explain.

In a recently presented study, 20 patients with intractable bacterial infections were treated with phages. In the journal Clinical Infectious Diseases, researchers reported that the treatment was successful in eleven patients. Accordingly, there were no side effects. Ziehr refers to a heterogeneous group of participants, which included children as well as adults with different clinical pictures, complex infections and different types of pathogens. The expert, who was not involved in the work, says that the fact that, under these conditions, more than half of the participants responded to treatment is impressive.

Germs won’t completely replace antibiotics, experts assure. A promising approach could be a combination of phages and antibiotics, based on what is called phage-antibiotic synergy (PAS), explains phage researcher Berlin Willy. It has been shown that resistant bacteria can become sensitive to antibiotics again in a patient previously treated with phages.

© dpa-infocom, dpa: 220615-99-671694 / 2

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