Dna, methods etc

An antibacterial composition comprising a plurality of non self-replicative transduction particles comprising a nucleic acid encoding an antibacterial agent or component thereof, wherein the antibacterial agent is toxic to target bacterial cells, wherein the particles are capable of transducing into the target bacterial cells the nucleic acid encoding the antibacterial agent or component thereof for expression of the antibacterial agent or component in the target bacterial cells;

• wherein
• a) the antibacterial agent comprises a guided nuclease system;
• b) the particles comprise one, more or all of the tail proteins, portal protein and tail fiber proteins of a first phage and capsid proteins of the first phage;
• c) the nucleic acid comprises an origin of replication (ori) operable in a bacterial host cell for replication of the nucleic acid encoding the antibacterial agent or component thereof, wherein the first phage is capable of infecting cells of the same species or strain as the bacterial host cell;
• d) the nucleic acid comprises a packaging signal comprising a pac, cos or a homologue thereof that is operable with the first phage to package the nucleic acid in non self-replicative transduction particles;
• e) the particles are devoid of all phage terminase genes;
• and
• f) the particles are devoid of all phage structural protein genes.