Specific antibodies capture germs


We are developing a rapid test for three important bacterial pathogens. The test is based on specific antibody fragments that bind directly to and capture pathogens in blood samples.

Project description (ongoing research project)

It can take several days to detect the pathogen responsible for blood poisoning (sepsis). A lot of time is lost in current tests due to the need to replicate bacteria. We are working on a process that is substantially faster because it can isolate pathogens straight from blood samples. Our method uses synthetic antibody fragments – what are known as sybodies – that bind to pathogens. To do so, they need a structure that is adapted to the bacterial species in question. As a first step, we are therefore developing sybodies that will specifically dock to all clinically relevant strains of the E. coli, K. pneumoniae and P. aeruginosa bacteria. This will provide a basis for developing a rapid test capable of quickly analysing these pathogens by counting individual cells and testing them for antibiotic resistance.


Conventional antibodies bind primarily to highly variable sugar structures that vary widely not only between bacterial species, but also between various strains within a particular species. Such complexity rules out the use of these antibodies in diagnostics. We overcome this problem by developing small antibody fragments against highly conserved proteins. These will facilitate the rapid isolation of pathogens from blood samples and permit significantly faster diagnosis than is possible with the tests currently in use.


We aim to identify and manufacture antibody fragments that will bind specifically to particular bacterial species and use them to develop a rapid test.


Sepsis causes death in 15–30% of cases. The fact that an increasing number of bacteria responsible for sepsis are resistant to certain antibiotics has exacerbated the problem recently. Our method will crucially accelerate the process of detecting three clinically relevant strains, thus gaining valuable time in which to initiate treatment with an effective antibiotic.

Original title

Rapid diagnostics of blood stream infections using synthetic nanobodies

Project leaders

  • Prof. Markus Seeger, Institut für Medizinische Mikrobiologie, Universität Zürich
  • Dr. Peter Michael Keller, Institut für Medizinische Mikrobiologie, Universität Zürich



Further information on this content



Prof. Markus Seeger Institut für Medizinische Mikrobiologie Universität Zürich Gloriastrasse 30/32 8006 Zürich +41 44 634 53 96