The aim of the project is to build a semi-operation; proven technology of medicinal preparations against opportunistic bacterial infections caused by Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pneumoniae, Klebsiella pneumoniae, E. coli, Haemophilus influenzae forming biofilm, based on lytic phages and recombinant endolysins. Selected phage and endolysin candidates will be tested in vitro and in vivo for their efficacy and harmlessness using experimental animal species (mice, rabbit) experimentally infected with the relevant pathogen. The result of the project will be the development of effective preparation of specific phages and endolysins, methods of their control and optimal pharmaceutical form.