Previous Article | Next Article 
Infection and Immunity, March 2006, p. 1683-1691, Vol. 74, No. 3
0019-9567/06/$08.00+0 doi:10.1128/IAI.74.3.1683-1691.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.
Identification of Legionella pneumophila-Specific Genes by Genomic Subtractive Hybridization with Legionella micdadei and Identification of lpnE, a Gene Required for Efficient Host Cell Entry
Hayley J. Newton,1
Fiona M. Sansom,1
Vicki Bennett-Wood,2,3 and
Elizabeth L. Hartland1,3*
Australian Bacterial Pathogenesis Program, Department of Microbiology, Monash University, Victoria 3800,1
Australian Bacterial Pathogenesis Program, Department of Microbiology and Immunology, University of Melbourne, Victoria 3010,2
Microbiological Research Unit, Murdoch Children's Research Institute and Royal Children's Hospital, Parkville Victoria 3052, Australia3
Received 30 August 2005/
Returned for modification 27 October 2005/
Accepted 13 December 2005
Legionella pneumophila is a ubiquitous environmental organism and a facultative intracellular pathogen of humans. To identify genes that may contribute to the virulence of L. pneumophila, we performed genomic subtractive hybridization between L. pneumophila serogroup 1 strain 02/41 and L. micdadei strain 02/42. A total of 144 L. pneumophila-specific clones were sequenced, revealing 151 genes that were absent in L. micdadei strain 02/42. Low-stringency Southern hybridization was used to determine the distribution of 41 sequences, representing 40 open reading frames (ORFs) with a range of putative functions among L. pneumophila isolates of various serogroups as well as strains of Legionella longbeachae, L. micdadei, Legionella gormanii, and Legionella jordanis. Twelve predicted ORFs were L. pneumophila specific, including the gene encoding the dot/icm effector, lepB, as well as several genes predicted to play a role in lipopolysaccharide biosynthesis and cell wall synthesis and several sequences with similarity to virulence-associated determinants. A further nine predicted ORFs were in all L. pneumophila serotypes tested and an isolate of L. gormanii. These included icmD, the 5' end of a pilMNOPQ locus, and two genes known to be upregulated during growth within macrophages, cadA2 and ceaA. Disruption of an L. pneumophila-specific gene (lpg2222 locus tag) encoding a putative protein with eight tetratricopeptide repeats resulted in reduced entry into the macrophage-like cell line, THP-1, and the type II alveolar epithelial cell line, A549. The gene was subsequently renamed lpnE, for "L. pneumophila entry." In summary, this investigation has revealed important genetic differences between L. pneumophila and other Legionella species that may contribute to the phenotypic and clinical differences observed within this genus.
* Corresponding author. Mailing address: Department of Microbiology, Monash University, Victoria 3800, Australia, Phone: (61) 3 9905 4323. Fax: (61) 3 9905 4811. E-mail:
Liz.Hartland{at}med.monash.edu.au.
Editor: J. N. Weiser
Supplemental material for this article may be found at http://iai.asm.org/.
Infection and Immunity, March 2006, p. 1683-1691, Vol. 74, No. 3
0019-9567/06/$08.00+0 doi:10.1128/IAI.74.3.1683-1691.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.
This article has been cited by other articles:
-
Chong, A., Lima, C. A., Allan, D. S., Nasrallah, G. K., Garduno, R. A.
(2009). The Purified and Recombinant Legionella pneumophila Chaperonin Alters Mitochondrial Trafficking and Microfilament Organization. Infect. Immun.
77: 4724-4739
[Abstract]
[Full Text]
-
Allard, K. A., Dao, J., Sanjeevaiah, P., McCoy-Simandle, K., Chatfield, C. H., Crumrine, D. S., Castignetti, D., Cianciotto, N. P.
(2009). Purification of Legiobactin and Importance of This Siderophore in Lung Infection by Legionella pneumophila. Infect. Immun.
77: 2887-2895
[Abstract]
[Full Text]
-
Brombacher, E., Urwyler, S., Ragaz, C., Weber, S. S., Kami, K., Overduin, M., Hilbi, H.
(2009). Rab1 Guanine Nucleotide Exchange Factor SidM Is a Major Phosphatidylinositol 4-Phosphate-binding Effector Protein of Legionella pneumophila. J. Biol. Chem.
284: 4846-4856
[Abstract]
[Full Text]
-
Tiaden, A., Spirig, T., Carranza, P., Bruggemann, H., Riedel, K., Eberl, L., Buchrieser, C., Hilbi, H.
(2008). Synergistic Contribution of the Legionella pneumophila lqs Genes to Pathogen-Host Interactions. J. Bacteriol.
190: 7532-7547
[Abstract]
[Full Text]
-
Newton, H. J., Sansom, F. M., Dao, J., Cazalet, C., Bruggemann, H., Albert-Weissenberger, C., Buchrieser, C., Cianciotto, N. P., Hartland, E. L.
(2008). Significant Role for ladC in Initiation of Legionella pneumophila Infection. Infect. Immun.
76: 3075-3085
[Abstract]
[Full Text]
-
Sansom, F. M., Riedmaier, P., Newton, H. J., Dunstone, M. A., Muller, C. E., Stephan, H., Byres, E., Beddoe, T., Rossjohn, J., Cowan, P. J., d'Apice, A. J. F., Robson, S. C., Hartland, E. L.
(2008). Enzymatic Properties of an Ecto-nucleoside Triphosphate Diphosphohydrolase from Legionella pneumophila: SUBSTRATE SPECIFICITY AND REQUIREMENT FOR VIRULENCE. J. Biol. Chem.
283: 12909-12918
[Abstract]
[Full Text]
-
Newton, H. J., Sansom, F. M., Dao, J., McAlister, A. D., Sloan, J., Cianciotto, N. P., Hartland, E. L.
(2007). Sel1 Repeat Protein LpnE Is a Legionella pneumophila Virulence Determinant That Influences Vacuolar Trafficking. Infect. Immun.
75: 5575-5585
[Abstract]
[Full Text]
-
Li, J., Ryder, C., Mandal, M., Ahmed, F., Azadi, P., Snyder, D. S., Pechous, R. D., Zahrt, T., Inzana, T. J.
(2007). Attenuation and protective efficacy of an O-antigen-deficient mutant of Francisella tularensis LVS. Microbiology
153: 3141-3153
[Abstract]
[Full Text]
-
DebRoy, S., Dao, J., Soderberg, M., Rossier, O., Cianciotto, N. P.
(2006). Legionella pneumophila type II secretome reveals unique exoproteins and a chitinase that promotes bacterial persistence in the lung. Proc. Natl. Acad. Sci. USA
103: 19146-19151
[Abstract]
[Full Text]