Patent ID: 8021672

Claim:
An isolated plasmid-deficient Chlamydia sp. strain wherein the strain causes reduced pathology as compared to a corresponding plasmid-containing disease-causing Chlamydia strain in a vertebrate; and wherein following inoculation with the plasmid-deficient Chlamydia strain, when a vertebrate is infected with the corresponding plasmid-containing disease-causing strain the vertebrate experiences reduced pathology as compared to a vertebrate not previously inoculated with the plasmid-deficient Chlamydia strain; wherein the strain is prepared by a process comprising: treating the plasmid-containing disease-causing Chlamydia sp. strain under conditions that cure it of the plasmid to generate a population of treated Chlamydia; incubating host cells with the treated Chlamydia under conditions permissive for infection by plasmid-deficient Chlamydia to infect the host cells; culturing the Chlamydia in the host cells and isolating plaques of Chlamydia from the host cells; and verifying that Chlamydia from the isolated plaques are plasmid-deficient; and wherein the strain does not stimulate TLR2-dependent IL-8 secretion.