Abstract: The present invention relates to a method for screening for changes in the infectivity range of one or more bacteriophages due to epigenetic imprinting of the bacteriophage(s) as well as a method for screening for one or more bacteriophages with a specific infectivity range due to the epigenetic imprinting of the bacteriophages. The invention furthermore relates to compositions comprising bacteriophages identified and obtained or obtainable by these methods and their use in therapy as well as for the selective killing of bacteria.

Abstract: A nucleic acid constructs are used in improving site-specific insertion of an exogenous nucleic acid into a genome. In some aspects the nucleic acid construct having a first polynucleotide sequence encoding a DNA binding protein engineered to bind to a specific genomic DNA sequence, a second polynucleotide having a modified integrase or a modified transposase that enables insertion of exogenous nucleic acid into the genome, and a nucleic acid sequence encoding a linker between the two nucleotides. In some aspects, the nucleic acid construct encodes a fusion protein, for example, a fusion protein for delivery to a cell by a lentiviral particle.