Patent ID: 6991786

Claim:
A recombinant donor bacterium-harboring at least one transmissible plasmid, said transmissible plasmid comprising: a) an origin of replication for synthesizing the plasmid in a bacterial cell, wherein initiation of replication at the origin is negatively controlled by a plasmid replication protein comprising a copy number control function, wherein in the absence of the plasmid replication protein copy number control function, the transmissible plasmid undergoes runaway replication; b) a mutant gene encoding a plasmid replication protein comprising a copy number control function, wherein said mutant gene encoding said plasmid replication protein comprises a mutation that reduces the copy number control function of said plasmid replication protein; c) an origin of transfer from which conjugative transfer of the transmissible plasmid initiates from the donor bacterium to at least one recipient bacterium; d) at least one screenable marker gene; wherein the donor bacterium further comprises one or more transfer genes conferring upon the donor bacterium the ability to conjugatively transfer the transmissible plasmid to the recipient bacterium, and wherein the donor bacterium further comprises a wild type gene encoding said plasmid replication protein comprising a copy number control function, and further wherein the at least one recipient bacterium is a pathogenic bacterium that does not produce the plasmid replication protein comprising a copy number control function, thereby enabling the transmissible plasmid to undergo runaway replication in the recipient bacterium.