title: SCID mouse model for lethal Q fever.
abstract: Q fever, a worldwide zoonosis caused by Coxiella burnetii, has many manifestations in humans. Endocarditis is the most serious complication of Q fever. Animal models are limited to acute pulmonary or hepatic disease and reproductive disorders. An appropriate experimental animal model for Q fever endocarditis does not yet exist. In this study, severe combined immunodeficient (SCID) mice infected with C. burnetii showed persistent clinical symptoms and died, whereas immunocompetent mice similarly infected became asymptomatic and survived. The SCID mice examined in this study had severe chronic lesions in their primary organs: the heart, lung, spleen, liver, and kidney. The heart lesions of the SCID mice were similar to those in humans with chronic Q fever endocarditis: they had focal calcification and expanded macrophages containing C. burnetii. The 50% lethal dose of C. burnetii in SCID mice was at least 10(8) times less than that in immunocompetent mice. The SCID mouse is highly susceptible to C. burnetii, and the immunodeficiency of the host enhances the severity of Q fever. This animal model could provide a new tool for the study of chronic Q fever and Q fever in immunodeficient hosts.
authors.affiliation: Department of Veterinary Microbiology, Faculty of Agriculture, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1193, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Andoh
authors.forename: Takashi
authors.initials: T
authors.lastname: Naganawa
authors.forename: Akitoyo
authors.initials: A
authors.lastname: Hotta
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Hideto
authors.initials: H
authors.lastname: Fukushi
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Masegi
authors.forename: Katsuya
authors.initials: K
authors.lastname: Hirai
mesh_terms: D000818:Animals; D002908:Chronic Disease; D015169:Colony Count, Microbial; D016997:Coxiella burnetii / Q000472:pathogenicity; D004195:Disease Models, Animal; D004697:Endocarditis, Bacterial / Q000209:etiology / Q000276:immunology / Q000473:pathology; D005260:Female; D006801:Humans; D007121:Immunocompetence; D051379:Mice; D016513:Mice, SCID; D011778:Q Fever / Q000209:etiology* / Q000276:immunology / Q000473:pathology