Bacteriophage variants having extended host-range, methods for preparation and uses thereof in transducing nucleic acids into hosts of interest

A method for preparing, identifying and/or isolating host recognition element/s compatible for a target cell of interest, the method comprising:

• a. providing a plurality of nucleic acid molecules encoding at least one host-recognition element or any variant, mutant, protein or fragment thereof, wherein said nucleic acid molecules further comprise at least one packaging signal and at least one nucleic acid sequence encoding a selectable element;
• b. contacting first host cell/s comprising said plurality of nucleic acid molecules with a delivery vehicle that carries nucleic acid sequence/s encoding at least one defective host recognition element or any protein or fragment thereof, under conditions that allow packaging and/or propagation of said delivery vehicle, and recovering the resultant delivery vehicle variants propagated and/or packaged in said first host cell/s;
• c. contacting second host cell/s with the delivery vehicle variants recovered in step (b);
• d. selecting for host cells obtained in step (c) that comprise said selectable element;
• and
• e. isolating and/or characterizing the at least one host recognition element/s or any nucleic acid sequence encoding the same, from the host cell/s selected in step (d), to obtain at least one host recognition element compatible with at least one of said second host cell and said target cell/s of interest, or a nucleic acid sequence encoding the same.