title: Bioluminescence imaging of Chlamydia muridarum ascending infection in mice.
abstract: Chlamydial pathogenicity in the upper genital tract relies on chlamydial ascending from the lower genital tract. To monitor chlamydial ascension, we engineered a luciferase-expressing C. muridarum. In cells infected with the luciferase-expressing C. muridarum, luciferase gene expression and enzymatic activity (measured as bioluminescence intensity) correlated well along the infection course, suggesting that bioluminescence can be used for monitoring chlamydial replication. Following an intravaginal inoculation with the luciferase-expressing C. muridarum, 8 of 10 mice displayed bioluminescence signal in the lower with 4 also in the upper genital tracts on day 3 after infection. By day 7, all 10 mice developed bioluminescence signal in the upper genital tracts. The bioluminescence signal was maintained in the upper genital tract in 6 and 2 mice by days 14 and 21, respectively. The bioluminescence signal was no longer detectable in any of the mice by day 28. The whole body imaging approach also revealed an unexpected airway infection following the intravaginal inoculation. Although the concomitant airway infection was transient and did not significantly alter the genital tract infection time courses, caution should be taken during data interpretation. The above observations have demonstrated that C. muridarum can not only achieve rapid ascending infection in the genital tract but also cause airway infection following a genital tract inoculation. These findings have laid a foundation for further optimizing the C. muridarum intravaginal infection murine model for understanding chlamydial pathogenic mechanisms.
authors.affiliation: Department of Obstetrics and Gynecology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Jessica
authors.initials: J
authors.lastname: Campbell
authors.affiliation: Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Yumeng
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Yuanjun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Obstetrics and Gynecology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Robert
authors.initials: R
authors.lastname: Schenken
authors.affiliation: Department of Biology, University of Texas at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Bernard
authors.initials: B
authors.lastname: Arulanandam
authors.affiliation: Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zhong
mesh_terms: D000818:Animals; D002690:Chlamydia Infections / Q000473:pathology*; D023502:Chlamydia muridarum / Q000235:genetics / Q000378:metabolism; D005260:Female; D006367:HeLa Cells; D006801:Humans; D008156:Luciferases / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D057054:Molecular Imaging; D060737:Reproductive Tract Infections / Q000382:microbiology / Q000473:pathology*
chemical_list: D008156:Luciferases