Interim report of the DSMZ laboratory

The first stage „selection of phages“ within the joint project „Phage4Cure“ consists of the targeted search for bacteriophages, their clonal purification, characterization, comparison, propagation and appropriation for further pharmaceutical development. These steps form the essential phage biology in the initial part of the project. Aim of this joint project is to prepare a variety of phages, that complement one another in terms of their host spectrum; as antiinfective agents against the multiresistant bacterium Pseudomonas aeruginosa.

Electron-microscopical shot of pseudomonads with docked bacteriophages. Copyright M. Rohde, HZI

During this process a great variety of Pseudomonas phages will be tested for their effectiveness against a broad spectrum of Pseudomonas strains. These bacterial strains were isolated from a variety of patients in international clinics. Phages are now met with the challenge to win the fight against multiresistant bacteria after the failure of antibiotics. The most difficult aspect of phage biology is the physicochemical receptor recognition of phages when coming into contact with bacterial surfaces. The effectiveness of this highly specific ability of each phage to bind with the bacteria ultimately leads to the destruction of the bacteria.

Since the start of the project the screening of phages in the laboratories of Leibniz-Institut DSMZ GmbH has already produced some promising results. Quantitative comparison of phage efficiency, morphology, and genetic make-up have produced evaluation patterns that represent the next milestone for Phage4Cure. This will be the selection of the therapeutically most effective phages for transfer to Fraunhofer ITEM where a production procedure for the growth and purification of the phages will be put into place. Ultimately this reproducible procedure should produce pharmaceutically pure phages that can then be used in the next steps of the project.