title: Discovering and differentiating new and emerging clonal populations of Chlamydia trachomatis with a novel shotgun cell culture harvest assay.
abstract: Chlamydia trachomatis is the leading cause of preventable blindness and bacterial sexually transmitted diseases worldwide. Plaque assays have been used to clonally segregate laboratory-adapted C. trachomatis strains from mixed infections, but no assays have been reported to segregate clones from recent clinical samples. We developed a novel shotgun cell culture harvest assay for this purpose because we found that recent clinical samples do not form plaques. Clones were strain-typed by using outer membrane protein A and 16S rRNA sequences. Surprisingly, ocular trachoma reference strain A/SA-1 contained clones of Chlamydophila abortus. C. abortus primarily infects ruminants and pigs and has never been identified in populations where trachoma is endemic. Three clonal variants of reference strain Ba/Apache-2 were also identified. Our findings reflect the importance of clonal isolation in identifying constituents of mixed infections containing new or emerging strains and of viable clones for research to more fully understand the dynamics of in vivo strain-mixing, evolution, and disease pathogenesis.
authors.affiliation: Children's Hospital, Oakland Research Institute, Oakland, California, USA.
authors.forename: Naraporn
authors.initials: N
authors.lastname: Somboonna
authors.forename: Sally
authors.initials: S
authors.lastname: Mead
authors.forename: Jessica
authors.initials: J
authors.lastname: Liu
authors.forename: Deborah
authors.initials: D
authors.lastname: Dean
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001431:Bacteriological Techniques / Q000379:methods*; D002690:Chlamydia Infections / Q000382:microbiology*; D002692:Chlamydia trachomatis / Q000145:classification* / Q000235:genetics*; D023501:Chlamydophila / Q000235:genetics; D005798:Genes, Bacterial; D014644:Genetic Variation; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D001425:Bacterial Outer Membrane Proteins; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; C078167:OMPA outer membrane proteins