In this project new lytic phages against S. aureus and S. aureus MRSA strains that are relevant to be isolated farm animals. New insulation is done with a view to the application of a larger collection of lytic phages strictly to the use in a faagcocktail increases, which may be appropriate in order to prevent resistance with respect to phage infection. A wide / diverse host range (including MRSA clone ST 398), clear plaques (strictly virulent character), storage stability and reduced genome content apply as first selection. In addition, characteristics referred to will also be determined for the period strictly lytic phage phiSPL (available). Phage phiSPL was isolated from Staphylococcus Phage Lysate (Delmont's Lab, USA), a preparation used in the US in veterinary medicine to stimulate the immune system specifically (a demonstrable effect against S. aureus infections, personal communication Prof. . E. Kutter). The genome sequence of the phage phiSPL will be determined. In addition, also the genome sequence of a maximum of 2 new strictly lytic phages (that meet the desired selection criteria) can be determined. Of these three phages, a 'streamlined' functional characterization will be performed (expertise available in the Laboratory for Genetic Engineering). This can be clearly assessed the safety of phages according to their genomic and protein content (absence virulence genes, toxins, cellular elements). a treatment with the aid of the efficacy, safety, and stability of the antibacterial nature of strictly lytic phages will be examined in the form of two compositions, namely, (1) a treatment with one strictly lytic phage (phiSPL) and (2) a faagcocktail with between 2 to 4 strictly lytic phages. The efficacy, safety, and stability will be in two relevant contexts from S. aureus / MRSA problems to be studied in farm animals, viz. For the control of MRSA colonization in farm animals and for the treatment of S. aureus-induced skin infections. For the proof-of-concept will hereby infection in rabbit be used as a model. In addition, the safety of the optimal herapie will be evaluated for use in pig, rabbit and chicken.