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Rapid dissemination of Francisella tularensis and the effect of route of infection.
- Source :
-
BMC microbiology [BMC Microbiol] 2008 Dec 09; Vol. 8, pp. 215. Date of Electronic Publication: 2008 Dec 09. - Publication Year :
- 2008
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Abstract
- Background: Francisella tularensis subsp. tularensis is classified as a Category A bioweapon that is capable of establishing a lethal infection in humans upon inhalation of very few organisms. However, the virulence mechanisms of this organism are not well characterized. Francisella tularensis subsp. novicida, which is an equally virulent subspecies in mice, was used in concert with a microPET scanner to better understand its temporal dissemination in vivo upon intranasal infection and how such dissemination compares with other routes of infection. Adult mice were inoculated intranasally with F. tularensis subsp. novicida radiolabeled with 64Cu and imaged by microPET at 0.25, 2 and 20 hours post-infection.<br />Results: 64Cu labeled F. tularensis subsp. novicida administered intranasally or intratracheally were visualized in the respiratory tract and stomach at 0.25 hours post infection. By 20 hours, there was significant tropism to the lung compared with other tissues. In contrast, the images of radiolabeled F. tularensis subsp. novicida when administered intragastrically, intradermally, intraperitoneally and intravenouslly were more generally limited to the gastrointestinal system, site of inoculation, liver and spleen respectively. MicroPET images correlated with the biodistribution of isotope and bacterial burdens in analyzed tissues.<br />Conclusion: Our findings suggest that Francisella has a differential tissue tropism depending on the route of entry and that the virulence of Francisella by the pulmonary route is associated with a rapid bacteremia and an early preferential tropism to the lung. In addition, the use of the microPET device allowed us to identify the cecum as a novel site of colonization of Francisella tularensis subsp. novicida in mice.
- Subjects :
- Animals
Copper Radioisotopes analysis
Francisella tularensis isolation & purification
Gastrointestinal Tract microbiology
Liver microbiology
Lung microbiology
Mice
Mice, Inbred C57BL
Positron-Emission Tomography methods
Spleen microbiology
Staining and Labeling
Whole Body Imaging methods
Francisella tularensis pathogenicity
Tularemia microbiology
Tularemia pathology
Subjects
Details
- Language :
- English
- ISSN :
- 1471-2180
- Volume :
- 8
- Database :
- MEDLINE
- Journal :
- BMC microbiology
- Publication Type :
- Academic Journal
- Accession number :
- 19068128
- Full Text :
- https://doi.org/10.1186/1471-2180-8-215