Expression of the chlamydial genus-specific lipopolysaccharide epitope in Escherichia coli.

The obligate intracellular prokaryote Chlamydia trachomatis is the etiological agent of trachoma and is a primary causative pathogen of sexually transmitted genital tract disease; both diseases affect millions of people each year. The cloning of genes encoding the enzyme or enzymes producing the genus-specific lipopolysaccharide antigen of Chlamydia into Escherichia coli is reported here. The cloned chlamydial lipopolysaccharide antigen appears to be a hybrid lipopolysaccharide molecule composed of both Chlamydia and Escherichia coli components. The chlamydial lipopolysaccharide antigen is expressed on the surfaces of the viable Escherichia coli recombinants. These findings may have a significant impact on defining the role of this highly conserved antigen in the pathogenesis and diagnosis of chlamydial infections.