Skip to Main content Skip to Navigation
Journal articles

Encapsulated Bacillus anthracis interacts closely with liver endothelium.

Abstract : BACKGROUND: The Bacillus anthracis poly-gamma-D-glutamate capsule is essential for virulence. It impedes phagocytosis and protects bacilli from the immune system, thus promoting systemic dissemination. METHODS: To further define the virulence mechanisms brought into play by the capsule, we characterized the interactions between encapsulated nontoxinogenic B. anthracis and its host in vivo through histological analysis, perfusion, and competition experiments with purified capsule. RESULTS: Clearance of encapsulated bacilli from the blood was rapid (>90% clearance within 5 min), with 75% of the bacteria being trapped in the liver. Competition experiments with purified capsule polyglutamate inhibited this interaction. At the septicemic phase of cutaneous infection with spores, the encapsulated bacilli were trapped in the vascular spaces of the liver and interacted closely with the liver endothelium in the sinusoids and terminal and portal veins. They often grow as microcolonies containing capsular material shed by the bacteria. CONCLUSION: We show that, in addition to its inhibitory effect on the interaction with the immune system, the capsule surrounding B. anthracis plays an active role in mediating the trapping of the bacteria within the liver and may thus contribute to anthrax pathogenesis. Because other microorganisms produce polyglutamate, it may also represent a general mechanism of virulence or in vivo survival.
Document type :
Journal articles
Complete list of metadatas

Cited literature [41 references]  Display  Hide  Download

https://hal-pasteur.archives-ouvertes.fr/pasteur-00512101
Contributor : Mireille Ferrand <>
Submitted on : Friday, September 10, 2010 - 5:38:31 PM
Last modification on : Friday, October 23, 2020 - 4:41:28 PM
Long-term archiving on: : Saturday, December 11, 2010 - 2:35:04 AM

File

Piris-gimenez-JID.pdf
Publisher files allowed on an open archive

Identifiers

Collections

Citation

Alejandro Piris-Gimenez, Jean-Philippe Corre, Gregory Jouvion, Thomas Candela, Huot Khun, et al.. Encapsulated Bacillus anthracis interacts closely with liver endothelium.. Journal of Infectious Diseases, Oxford University Press (OUP), 2009, 200 (9), pp.1381-9. ⟨10.1086/644506⟩. ⟨pasteur-00512101⟩

Share

Metrics

Record views

245

Files downloads

477