| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Pathogenicity and Medical Microbiology |
Dept of Veterinary and Biomedical Sciences, University of Nebraska, Lincoln, 203 VBS, Fair and East Campus Loop, Lincoln, NE 68583, USA1
Author for correspondence: Jeffrey D. Cirillo. Tel: +1 402 472 8587. Fax: +1 402 472 9690. e-mail: jcirillo1{at}unl.edu
Legionella pneumophila is primarily an intracellular pathogen during infection; thus, the mechanisms of entry into host cells are likely to be important for pathogenesis. Several L. pneumophila mutants that display an enhanced-entry (Enh) phenotype were isolated by selecting for bacteria that enter host cells at a higher frequency than wild-type. In the course of characterizing the genetic basis of one of these mutants, C3, a strategy was developed for the isolation of laboratory-media-repressed virulence determinants from L. pneumophila. Screens for dominant mutations using a genomic DNA library from C3 resulted in the isolation of three cosmids that confer an Enh phenotype to wild-type L. pneumophila. Transposon mutagenesis of these cosmids allowed identification of three loci that affect entry. Analysis of the putative proteins encoded by these loci, designated rtxA and enhC, demonstrated similarity to repeats in the structural toxin protein and the secreted Sel-1 protein from Caenorhabditis elegans, respectively. L. pneumophila rtxA and enhC mutants display significantly reduced entry into host cells, compared to wild-type bacteria. The phenotype that the cosmids containing these loci confer is most likely due to elevated expression resulting from their presence on multicopy vectors. The use of increased gene copy number to overexpress genes that are normally repressed under laboratory growth conditions is generally applicable to the isolation of virulence determinants from L. pneumophila and other bacterial pathogens.
Keywords: phagocytosis, cytotoxicity, Sel-1, invasion, RTX
Abbreviations: Enh, enhanced entry (phenotype); RTX, structural toxin
The GenBank accession numbers for the enh1 and enh2 loci reported in this paper are AF057703 and AF057704, respectively.
This article has been cited by other articles:
|
|
 |
|
  P. Aurass, B. Pless, K. Rydzewski, G. Holland, N. Bannert, and A. Flieger bdhA-patD Operon as a Virulence Determinant, Revealed by a Novel Large-Scale Approach for Identification of Legionella pneumophila Mutants Defective for Amoeba Infection Appl. Envir. Microbiol., July 1, 2009; 75(13): 4506 - 4515. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Hovel-Miner, S. Pampou, S. P. Faucher, M. Clarke, I. Morozova, P. Morozov, J. J. Russo, H. A. Shuman, and S. Kalachikov {sigma}S Controls Multiple Pathways Associated with Intracellular Multiplication of Legionella pneumophila J. Bacteriol., April 15, 2009; 191(8): 2461 - 2473. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. A. Beare, N. Unsworth, M. Andoh, D. E. Voth, A. Omsland, S. D. Gilk, K. P. Williams, B. W. Sobral, J. J. Kupko III, S. F. Porcella, et al. Comparative Genomics Reveal Extensive Transposon-Mediated Genomic Plasticity and Diversity among Potential Effector Proteins within the Genus Coxiella Infect. Immun., February 1, 2009; 77(2): 642 - 656. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Tiaden, T. Spirig, P. Carranza, H. Bruggemann, K. Riedel, L. Eberl, C. Buchrieser, and H. Hilbi Synergistic Contribution of the Legionella pneumophila lqs Genes to Pathogen-Host Interactions J. Bacteriol., November 15, 2008; 190(22): 7532 - 7547. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. J. Newton, F. M. Sansom, J. Dao, C. Cazalet, H. Bruggemann, C. Albert-Weissenberger, C. Buchrieser, N. P. Cianciotto, and E. L. Hartland Significant Role for ladC in Initiation of Legionella pneumophila Infection Infect. Immun., July 1, 2008; 76(7): 3075 - 3085. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Park, S. Subbian, S. H. El-Etr, S. L. G. Cirillo, and J. D. Cirillo Use of Gene Dosage Effects for a Whole-Genome Screen To Identify Mycobacterium marinum Macrophage Infection Loci Infect. Immun., July 1, 2008; 76(7): 3100 - 3115. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. J. Newton, F. M. Sansom, J. Dao, A. D. McAlister, J. Sloan, N. P. Cianciotto, and E. L. Hartland Sel1 Repeat Protein LpnE Is a Legionella pneumophila Virulence Determinant That Influences Vacuolar Trafficking Infect. Immun., December 1, 2007; 75(12): 5575 - 5585. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. DebRoy, J. Dao, M. Soderberg, O. Rossier, and N. P. Cianciotto Legionella pneumophila type II secretome reveals unique exoproteins and a chitinase that promotes bacterial persistence in the lung PNAS, December 12, 2006; 103(50): 19146 - 19151. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. R. Bushell, S. P. Bottomley, J. Rossjohn, and T. Beddoe Tracking the Unfolding Pathway of a Multirepeat Protein via Tryptophan Scanning: EVIDENCE OF LOCALIZED INSTABILITY IN THE MITOCHONDRIAL IMPORT RECEPTOR Tom70 J. Biol. Chem., August 25, 2006; 281(34): 24345 - 24350. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Huang, Z. Yuan, B. A. Heron, B. R. Gray, S. Eglezos, J. R. Bates, and J. Savill Distribution of 19 major virulence genes in Legionella pneumophila serogroup 1 isolates from patients and water in Queensland, Australia. J. Med. Microbiol., August 1, 2006; 55(Pt 8): 993 - 997. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. J. Newton, F. M. Sansom, V. Bennett-Wood, and E. L. Hartland 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 Infect. Immun., March 1, 2006; 74(3): 1683 - 1691. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Chang, F. Kura, J. Amemura-Maekawa, N. Koizumi, and H. Watanabe Identification of a Novel Adhesion Molecule Involved in the Virulence of Legionella pneumophila Infect. Immun., July 1, 2005; 73(7): 4272 - 4280. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. H. El-Etr, S. Subbian, S. L. G. Cirillo, and J. D. Cirillo Identification of Two Mycobacterium marinum Loci That Affect Interactions with Macrophages Infect. Immun., December 1, 2004; 72(12): 6902 - 6913. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. A. Coleman, E. R. Fischer, D. Howe, D. J. Mead, and R. A. Heinzen Temporal Analysis of Coxiella burnetii Morphological Differentiation J. Bacteriol., November 1, 2004; 186(21): 7344 - 7352. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Chien, I. Morozova, S. Shi, H. Sheng, J. Chen, S. M. Gomez, G. Asamani, K. Hill, J. Nuara, M. Feder, et al. The Genomic Sequence of the Accidental Pathogen Legionella pneumophila Science, September 24, 2004; 305(5692): 1966 - 1968. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Huang, B. A. Heron, B. R. Gray, S. Eglezos, J. R. Bates, and J. Savill A Predominant and Virulent Legionella pneumophila Serogroup 1 Strain Detected in Isolates from Patients and Water in Queensland, Australia, by an Amplified Fragment Length Polymorphism Protocol and Virulence Gene-Based PCR Assays J. Clin. Microbiol., September 1, 2004; 42(9): 4164 - 4168. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Bandyopadhyay, H. Xiao, H. A. Coleman, A. Price-Whelan, and H. M. Steinman Icm/Dot-Independent Entry of Legionella pneumophila into Amoeba and Macrophage Hosts Infect. Immun., August 1, 2004; 72(8): 4541 - 4551. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Flieger, K. Rydzewski, S. Banerji, M. Broich, and K. Heuner Cloning and Characterization of the Gene Encoding the Major Cell-Associated Phospholipase A of Legionella pneumophila, plaB, Exhibiting Hemolytic Activity Infect. Immun., May 1, 2004; 72(5): 2648 - 2658. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. Ridenour, S. L. G. Cirillo, S. Feng, M. M. Samrakandi, and J. D. Cirillo Identification of a Gene That Affects the Efficiency of Host Cell Infection by Legionella pneumophila in a Temperature-Dependent Fashion Infect. Immun., November 1, 2003; 71(11): 6256 - 6263. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Seshadri, I. T. Paulsen, J. A. Eisen, T. D. Read, K. E. Nelson, W. C. Nelson, N. L. Ward, H. Tettelin, T. M. Davidsen, M. J. Beanan, et al. Complete genome sequence of the Q-fever pathogen Coxiellaburnetii PNAS, April 29, 2003; 100(9): 5455 - 5460. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Garduno, E. Garduno, M. Hiltz, and P. S. Hoffman Intracellular Growth of Legionella pneumophila Gives Rise to a Differentiated Form Dissimilar to Stationary-Phase Forms Infect. Immun., November 1, 2002; 70(11): 6273 - 6283. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. L. G. Cirillo, L. Yan, M. Littman, M. M. Samrakandi, and J. D. Cirillo Role of the Legionella pneumophila rtxA gene in amoebae Microbiology, June 1, 2002; 148(6): 1667 - 1677. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. M. Samrakandi, S. L. G. Cirillo, D. A. Ridenour, L. E. Bermudez, and J. D. Cirillo Genetic and Phenotypic Differences between Legionella pneumophila Strains J. Clin. Microbiol., April 1, 2002; 40(4): 1352 - 1362. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Molmeret, O. A. T. Alli, S. Zink, A. Flieger, N. P. Cianciotto, and Y. A. Kwaik icmT Is Essential for Pore Formation-Mediated Egress of Legionella pneumophila from Mammalian and Protozoan Cells Infect. Immun., January 1, 2002; 70(1): 69 - 78. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. H. El-Etr, L. Yan, and J. D. Cirillo Fish Monocytes as a Model for Mycobacterial Host-Pathogen Interactions Infect. Immun., December 1, 2001; 69(12): 7310 - 7317. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. L. G. Cirillo, L. E. Bermudez, S. H. El-Etr, G. E. Duhamel, and J. D. Cirillo Legionella pneumophila Entry Gene rtxA Is Involved in Virulence Infect. Immun., January 1, 2001; 69(1): 508 - 517. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |
