Previous Article | Next Article 
Journal of Bacteriology, July 2008, p. 4584-4595, Vol. 190, No. 13
0021-9193/08/$08.00+0 doi:10.1128/JB.00198-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.
The Francisella Pathogenicity Island Protein PdpD Is Required for Full Virulence and Associates with Homologues of the Type VI Secretion System
Jagjit S. Ludu,1
Olle M. de Bruin,1
Barry N. Duplantis,1
Crystal L. Schmerk,1
Alicia Y. Chou,2
Karen L. Elkins,2 and
Francis E. Nano1*
Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada,1
Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland2
Received 7 February 2008/
Accepted 28 April 2008
Francisella tularensis is a highly infectious, facultative intracellular bacterial pathogen that is the causative agent of tularemia. Nearly a century ago, researchers observed that tularemia was often fatal in North America but almost never fatal in Europe and Asia. The chromosomes of F. tularensis strains carry two identical copies of the Francisella pathogenicity island (FPI), and the FPIs of North America-specific biotypes contain two genes, anmK and pdpD, that are not found in biotypes that are distributed over the entire Northern Hemisphere. In this work, we studied the contribution of anmK and pdpD to virulence by using F. novicida, which is very closely related to F. tularensis but which carries only one copy of the FPI. We showed that anmK and pdpD are necessary for full virulence but not for intracellular growth. This is in sharp contrast to most other FPI genes that have been studied to date, which are required for intracellular growth. We also showed that PdpD is localized to the outer membrane. Further, overexpression of PdpD affects the cellular distribution of FPI-encoded proteins IglA, IglB, and IglC. Finally, deletions of FPI genes encoding proteins that are homologues of known components of type VI secretion systems abolished the altered distribution of IglC and the outer membrane localization of PdpD.
* Corresponding author. Mailing address: Department of Biochemistry and Microbiology, P.O. Box 3055 STN CSC, University of Victoria, Victoria, BC V8W 3P6, Canada. Phone: (250) 721-7074. Fax: (250) 721-8855. E-mail:
fnano{at}uvic.ca
Published ahead of print on 9 May 2008.
Journal of Bacteriology, July 2008, p. 4584-4595, Vol. 190, No. 13
0021-9193/08/$08.00+0 doi:10.1128/JB.00198-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.
This article has been cited by other articles:
-
Grall, N., Livny, J., Waldor, M., Barel, M., Charbit, A., Meibom, K. L.
(2009). Pivotal role of the Francisella tularensis heat-shock sigma factor RpoH. Microbiology
155: 2560-2572
[Abstract]
[Full Text]
-
Di Bonaventura, M. P., DeSalle, R., Pop, M., Nagarajan, N., Figurski, D. H., Fine, D. H., Kaplan, J. B., Planet, P. J.
(2009). Complete Genome Sequence of Aggregatibacter (Haemophilus) aphrophilus NJ8700. J. Bacteriol.
191: 4693-4694
[Abstract]
[Full Text]
-
Buchan, B. W., McCaffrey, R. L., Lindemann, S. R., Allen, L.-A. H., Jones, B. D.
(2009). Identification of migR, a Regulatory Element of the Francisella tularensis Live Vaccine Strain iglABCD Virulence Operon Required for Normal Replication and Trafficking in Macrophages. Infect. Immun.
77: 2517-2529
[Abstract]
[Full Text]
-
Meibom, K. L., Forslund, A.-L., Kuoppa, K., Alkhuder, K., Dubail, I., Dupuis, M., Forsberg, A., Charbit, A.
(2009). Hfq, a Novel Pleiotropic Regulator of Virulence-Associated Genes in Francisella tularensis. Infect. Immun.
77: 1866-1880
[Abstract]
[Full Text]
-
Schmerk, C. L., Duplantis, B. N., Wang, D., Burke, R. D., Chou, A. Y., Elkins, K. L., Ludu, J. S., Nano, F. E.
(2009). Characterization of the pathogenicity island protein PdpA and its role in the virulence of Francisella novicida. Microbiology
155: 1489-1497
[Abstract]
[Full Text]
-
Schmerk, C. L., Duplantis, B. N., Howard, P. L., Nano, F. E.
(2009). A Francisella novicida pdpA mutant exhibits limited intracellular replication and remains associated with the lysosomal marker LAMP-1. Microbiology
155: 1498-1504
[Abstract]
[Full Text]
-
Broms, J. E., Lavander, M., Sjostedt, A.
(2009). A Conserved {alpha}-Helix Essential for a Type VI Secretion-Like System of Francisella tularensis. J. Bacteriol.
191: 2431-2446
[Abstract]
[Full Text]
-
Gallagher, L. A., McKevitt, M., Ramage, E. R., Manoil, C.
(2008). Genetic Dissection of the Francisella novicida Restriction Barrier. J. Bacteriol.
190: 7830-7837
[Abstract]
[Full Text]
-
Aschtgen, M.-S., Bernard, C. S., De Bentzmann, S., Lloubes, R., Cascales, E.
(2008). SciN Is an Outer Membrane Lipoprotein Required for Type VI Secretion in Enteroaggregative Escherichia coli. J. Bacteriol.
190: 7523-7531
[Abstract]
[Full Text]