Multiple host range bacteriophage with hybrid tail fibres

A modified bacteriophage capable of infecting a plurality of different target bacteria, wherein:

• (a) said bacteriophage includes an α/β small acid-soluble spore protein (SASP) gene encoding a SASP which is toxic to the target bacteria;
• (b) said bacteriophage expresses a single hybrid host range determinant protein which comprises an amino acid sequence derived from amino acid sequences of range determinant proteins from at least two different bacteriophages, and
• (c) said hybrid host range determinant protein is a tail fiber protein,
• (d) wherein said hybrid host range determinant protein comprises an N-terminal region wherein said N-terminal region binds to the body of said bacteriophage and a C-terminal region wherein said C-terminal region comprises a receptor binding region for binding to the target bacteria and wherein the amino acid sequence of said N-terminal region of said hybrid host range determinant protein is derived from a different bacteriophage than the amino acid sequence of said C-terminal region.