Exploiting the natural enemies of bacteria


Bacteriophages kill bacteria. We are investigating how the bacteriophages' weapons can be used as new therapeutics to combat local infections within the body.

Portrait / project description (ongoing research project)

Bacteria have natural enemies named bacteriophages. They use the bacteria as a host for the purpose of multiplication. When they leave the bacteria, they degrade the bacterial cell wall using specific enzymes, known as endolysins, causing the bacteria to die. We aim to develop therapeutics containing endolysins that are capable of destroying pathogenic bacteria. For them to be effective against local infections within the body, e.g. cases of inflammation of the bones or heart, they need to reach the infected sites. To achieve this, we put special target markers on endolysins. These “biological zip codes” guide them directly to the affected regions in the body.


Endolysins have been the subject of research for many years. However, the enzymes have to date only proven suitable for external applications (e.g. on the skin and on mucous membranes) due to their poor penetration into deeper tissue layers.


The aim of the project is to modify endolysins in such a way that they can be used against local infections within the body.


The sites where the endolysins cleave the cell walls of the bacteria are vital to the latter and can hardly be modified. It is therefore unlikely that bacteria will develop resistance against medicines containing endolysins. Consequently, such medicines would open up new therapeutic options that are less affected by problems of resistance than conventional antibiotics.

Original title

Novel targeted bacteriophage endolysin-based approach for treatment of drug-resistant Staphylococcus aureus infections

Project leaders

  • Prof. Martin Loessner, IFNH - D-HEST, ETH Zürich, Zürich
  • Fritz Eichenseher, IFNH - D-HEST, ETH Zürich, Zürich
  • Prof. Annelies Zinkernagel, Medizinische Klinik, Universitätsspital Zürich, Zürich
  • Dr. Yang Shen, IFNH - D-HEST, ETH Zürich, Zürich
  • Dr. Mathias Schmelcher, IFNH - D-HEST, ETH Zürich, Zürich



Further information on this content



Prof. Martin Loessner Labor für Lebensmittelmikrobiologie IFNH - D-HEST ETH Zürich Schmelzbergstrasse 7 8092 Zürich +41 44 632 33 33