title: Reduced live organism recovery and lack of hydrosalpinx in mice infected with plasmid-free Chlamydia muridarum.
abstract: Plasmid-free Chlamydia trachomatis and Chlamydia muridarum fail to induce severe pathology. To evaluate whether the attenuated pathogenicity is due to insufficient infection or inability of the plasmidless chlamydial organisms to trigger pathological responses, we compared plasmid-competent and plasmid-free C. muridarum infections in 5 different strains of mice. All 5 strains developed hydrosalpinx following intravaginal inoculation with plasmid-competent, but not inoculation with plasmid-free, C. muridarum. The lack of hydrosalpinx induction by plasmid-free C. muridarum correlated with significantly reduced live organism recovery from the lower genital tract and shortened infection in the upper genital tract. The plasmid-free C. muridarum organisms failed to induce hydrosalpinx even when the organisms were directly inoculated into the oviduct via an intrabursal injection, which was accompanied by significantly reduced survival of the plasmidless organisms in the genital tracts. Furthermore, plasmid-competent C. muridarum organisms after UV inactivation were no longer able to induce hydrosalpinx even when directly delivered into the oviduct at a high dose. Together, these observations suggest that decreased survival of and shortened infection with plasmid-free C. muridarum may contribute significantly to its attenuated pathogenicity. We conclude that adequate live chlamydial infection in the oviduct may be necessary to induce hydrosalpinx.
authors.affiliation: Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Lei
authors.forename: Jianlin
authors.initials: J
authors.lastname: Chen
authors.forename: Shuping
authors.initials: S
authors.lastname: Hou
authors.forename: Yiling
authors.initials: Y
authors.lastname: Ding
authors.forename: Zhangsheng
authors.initials: Z
authors.lastname: Yang
authors.forename: Hao
authors.initials: H
authors.lastname: Zeng
authors.forename: Joel
authors.initials: J
authors.lastname: Baseman
authors.forename: Guangming
authors.initials: G
authors.lastname: Zhong
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002690:Chlamydia Infections / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D023502:Chlamydia muridarum / Q000235:genetics / Q000276:immunology*; D002692:Chlamydia trachomatis / Q000235:genetics / Q000276:immunology; D005187:Fallopian Tubes / Q000276:immunology* / Q000473:pathology*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D010057:Oviducts / Q000276:immunology / Q000473:pathology; D010957:Plasmids / Q000235:genetics