Patent ID: 7758854

Claim:
A method of reducing or eliminating a target population of bacteria in a subject, the method comprising the step of: administering to the subject donor bacterial cells harboring a transmissible plasmid that comprises 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 bacterial cells to target bacterial cells, and d) at least one screenable marker gene, wherein each donor bacterial cell further comprises one or more transfer genes conferring upon the donor bacterial cell the ability to conjugatively transfer the transmissible plasmid to a target bacterial cell, wherein each donor bacterial cell further comprises a wild type gene encoding said plasmid replication protein comprising a copy number control function, wherein the target bacterial cells that do not produce the plasmid replication protein comprising a copy number control function, thereby enabling the transmissible plasmid to undergo runaway replication in the target bacterial cells, and wherein the donor bacterial cells are administered in a manner such that the donor bacterial cells contact the target bacterial cells and conjugatively transfer from the donor bacterial cells to the target bacterial cells, whereupon the transmissible plasmid undergoes runaway replication, thereby killing the target bacterial cells.