title: Q fever pneumonia: virulence of Coxiella burnetii pathovars in a murine model of aerosol infection.
abstract: Q fever is a worldwide zoonosis caused by Coxiella burnetii, a strictly intracellular bacterium that is a potential bioweapon. Humans usually acquires Q fever after inhalation of dust infected by subclinical animals. We used an aerosol exposure apparatus to challenge immunocompetent (BALB/c) and severe combined immunodeficient (SCID) mice with two different strains (strain Nine Mile and strain Q 212) of C. burnetii at two different inocula. Pathological lesions and dissemination of the bacteria were related to the size of the inoculum. SCID mice showed major pulmonary lesions, whereas similarly infected BALB/c mice were more able to eliminate the bacteria. Pathological differences were found between the strains, with Nine Mile showing more severe histological lesions and quantified spread of bacteria. Our animal model could provide a new tool for the study of acute Q fever pneumonia, the development of Q fever in immunodeficient hosts, and the differentiation of pathogenicity among C. burnetii isolates.
authors.affiliation: Unité des Rickettsies, Centre National de la Recherche Scientifique, UMR 6020, IFR 48, Faculté de Médecine, Université de la Méditerranée, Marseille, France.
authors.forename: Andreas
authors.initials: A
authors.lastname: Stein
authors.forename: Céline
authors.initials: C
authors.lastname: Louveau
authors.forename: Hubert
authors.initials: H
authors.lastname: Lepidi
authors.forename: Fanny
authors.initials: F
authors.lastname: Ricci
authors.forename: Pascal
authors.initials: P
authors.lastname: Baylac
authors.forename: Bernard
authors.initials: B
authors.lastname: Davoust
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D000336:Aerosols; D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis; D016997:Coxiella burnetii / Q000472:pathogenicity*; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D018410:Pneumonia, Bacterial / Q000276:immunology / Q000382:microbiology / Q000473:pathology*; D011778:Q Fever / Q000276:immunology / Q000382:microbiology / Q000473:pathology*; D014774:Virulence
chemical_list: D000336:Aerosols; D000942:Antigens, Bacterial