Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 27 March 2009:
Vol. 323. no. 5922, pp. 1729 - 1733
DOI: 10.1126/science.1169381
Prev | Table of Contents | Next

Reports

Infection by Tubercular Mycobacteria Is Spread by Nonlytic Ejection from Their Amoeba Hosts

Monica Hagedorn,1 Kyle H. Rohde,2 David G. Russell,2 Thierry Soldati1*

To generate efficient vaccines and cures for Mycobacterium tuberculosis, we need a far better understanding of its modes of infection, persistence, and spreading. Host cell entry and the establishment of a replication niche are well understood, but little is known about how tubercular mycobacteria exit host cells and disseminate the infection. Using the social amoeba Dictyostelium as a genetically tractable host for pathogenic mycobacteria, we discovered that M. tuberculosis and M. marinum, but not M. avium, are ejected from the cell through an actin-based structure, the ejectosome. This conserved nonlytic spreading mechanism requires a cytoskeleton regulator from the host and an intact mycobacterial ESX-1 secretion system. This insight offers new directions for research into the spreading of tubercular mycobacteria infections in mammalian cells.

1 Département de Biochimie, Faculté des Sciences, Université de Genève, Sciences II, 30 quai Ernest Ansermet, CH-1211 Genève-4, Switzerland.
2 Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.

* To whom correspondence should be addressed. E-mail: thierry.soldati{at}unige.ch

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Characterization of a Mycobacterium tuberculosis ESX-3 Conditional Mutant: Essentiality and Rescue by Iron and Zinc.
A. Serafini, F. Boldrin, G. Palu, and R. Manganelli (2009)
J. Bacteriol. 191, 6340-6344
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)