• K.pneumoniae
• bacteriophages
• environmental samples
• endolysin

The WHO defined the antibiotic resistance as one of the biggest threats to global health. Carbapenem-resistant Klebsiella pneumoniae is one of the pathogens for which novel treatment is a priority. ‘Phage Therapy’, antibacterial therapy based on the use of phage viruses, has remerged as a potential effective treatment alternative/adjuvant to antibiotics. Nowadays phage therapy is not acknowledged by control agencies and specific pharmaceutical criteria of stability and reproducibility to be validated are required. The aim of this thesis is the genotypic and phenotypic characterization of Klebsiella pneumoniae phages isolated from environmental samples and cloning of a putative endolysin. The lytic activity of isolated phages against K. pneumoniae clinical isolate strains, including NDM and KPC strains, was tested. Genome was extracted from all phages, sequenced and annotated. The killing kinetic of a preparation already used for personalised phage therapy has been performed such as studies about the synergism between phage and antibiotic. The cloning ,expression and purification of a putative endolysin were performed.