Curing the plasmid pXO2 from Bacillus anthracis A16 using plasmid incompatibility.

Plasmid incompatibility, which has no effect on other plasmids or chromosomal genes, can be used to cure a target plasmid. In this report, we successfully cured the plasmid pXO2 from Bacillus anthracis A16 with a newly constructed, incompatible plasmid pKSV7-oriIV and obtained a new pXO2-cured strain, designated A16PI2. This is the first time that a plasmid was cured from the B. anthracis wild-type strain A16 utilizing this principle, which could be considered as an efficacious method to cure large plasmids.