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Chatelet DS, Wistrom CM, Purcell AH, Rost TL, Matthews MA. Xylem structure of four grape varieties and 12 alternative hosts to the xylem-limited bacterium Xylella fastidious. ANNALS OF BOTANY 2011; 108:73-85. [PMID: 21546428 PMCID: PMC3119617 DOI: 10.1093/aob/mcr106] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 03/21/2011] [Indexed: 05/05/2023]
Abstract
BACKGROUND AND AIMS The bacterium Xylella fastidiosa (Xf), responsible for Pierce's disease (PD) of grapevine, colonizes the xylem conduits of vines, ultimately killing the plant. However, Vitis vinifera grapevine varieties differ in their susceptibility to Xf and numerous other plant species tolerate Xf populations without showing symptoms. The aim of this study was to examine the xylem structure of grapevines with different susceptibilities to Xf infection, as well as the xylem structure of non-grape plant species that support or limit movement of Xf to determine if anatomical differences might explain some of the differences in susceptibility to Xf. METHODS Air and paint were introduced into leaves and stems to examine the connectivity between stem and leaves and the length distribution of their vessels. Leaf petiole and stem anatomies were studied to determine the basis for the free or restricted movement of Xf into the plant. KEY RESULTS There were no obvious differences in stem or petiole vascular anatomy among the grape varieties examined, nor among the other plant species that would explain differences in resistance to Xf. Among grape varieties, the more tolerant 'Sylvaner' had smaller stem vessel diameters and 20 % more parenchyma rays than the other three varieties. Alternative hosts supporting Xf movement had slightly longer open xylem conduits within leaves, and more connection between stem and leaves, when compared with alternative hosts that limit Xf movement. CONCLUSIONS Stem--leaf connectivity via open xylem conduits and vessel length is not responsible for differences in PD tolerance among grape varieties, or for limiting bacterial movement in the tolerant plant species. However, it was found that tolerant host plants had narrower vessels and more parenchyma rays, possibly restricting bacterial movement at the level of the vessels. The implications of xylem structure and connectivity for the means and regulation of bacterial movement are discussed.
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Affiliation(s)
- David S. Chatelet
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02906, USA
| | - Christina M. Wistrom
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720-3114, USA
| | - Alexander H. Purcell
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720-3114, USA
| | - Thomas L. Rost
- Department of Plant Biology, University of California, Davis, CA 95616, USA
| | - Mark A. Matthews
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
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102
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Lackner G, Moebius N, Partida-Martinez LP, Boland S, Hertweck C. Evolution of an endofungal lifestyle: Deductions from the Burkholderia rhizoxinica genome. BMC Genomics 2011; 12:210. [PMID: 21539752 PMCID: PMC3102044 DOI: 10.1186/1471-2164-12-210] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 05/04/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Burkholderia rhizoxinica is an intracellular symbiont of the phytopathogenic zygomycete Rhizopus microsporus, the causative agent of rice seedling blight. The endosymbiont produces the antimitotic macrolide rhizoxin for its host. It is vertically transmitted within vegetative spores and is essential for spore formation of the fungus. To shed light on the evolution and genetic potential of this model organism, we analysed the whole genome of B. rhizoxinica HKI 0454 - a type strain of endofungal Burkholderia species. RESULTS The genome consists of a structurally conserved chromosome and two plasmids. Compared to free-living Burkholderia species, the genome is smaller in size and harbors less transcriptional regulator genes. Instead, we observed accumulation of transposons over the genome. Prediction of primary metabolic pathways and transporters suggests that endosymbionts consume host metabolites like citrate, but might deliver some amino acids and cofactors to the host. The rhizoxin biosynthesis gene cluster shows evolutionary traces of horizontal gene transfer. Furthermore, we analysed gene clusters coding for nonribosomal peptide synthetases (NRPS). Notably, B. rhizoxinica lacks common genes which are dedicated to quorum sensing systems, but is equipped with a large number of virulence-related factors and putative type III effectors. CONCLUSIONS B. rhizoxinica is the first endofungal bacterium, whose genome has been sequenced. Here, we present models of evolution, metabolism and tools for host-symbiont interaction of the endofungal bacterium deduced from whole genome analyses. Genome size and structure suggest that B. rhizoxinica is in an early phase of adaptation to the intracellular lifestyle (genome in transition). By analysis of tranporters and metabolic pathways we predict how metabolites might be exchanged between the symbiont and its host. Gene clusters for biosynthesis of secondary metabolites represent novel targets for genomic mining of cryptic natural products. In silico analyses of virulence-associated genes, secreted proteins and effectors might inspire future studies on molecular mechanisms underlying bacterial-fungal interaction.
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Affiliation(s)
- Gerald Lackner
- Leibniz Institute for Natural Product Research and Infection Biology (HKI), Department of Biomolecular Chemistry, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Nadine Moebius
- Leibniz Institute for Natural Product Research and Infection Biology (HKI), Department of Biomolecular Chemistry, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Laila P Partida-Martinez
- Leibniz Institute for Natural Product Research and Infection Biology (HKI), Department of Biomolecular Chemistry, Beutenbergstr. 11a, 07745 Jena, Germany
- Departamento de Ingeniería Genética, CINVESTAV-Irapuato, Km. 9.6 Libramiento Norte, CP 36821 Irapuato, Guanajuato, México
| | - Sebastian Boland
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
| | - Christian Hertweck
- Leibniz Institute for Natural Product Research and Infection Biology (HKI), Department of Biomolecular Chemistry, Beutenbergstr. 11a, 07745 Jena, Germany
- Friedrich Schiller University, 07743 Jena, Germany
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103
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Meyer MM, Kirkpatrick BC. Exogenous Applications of Abscisic Acid Increase Curing of Pierce's Disease-Affected Grapevines Growing in Pots. PLANT DISEASE 2011; 95:173-177. [PMID: 30743407 DOI: 10.1094/pdis-06-10-0446] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Foliar and drench applications of the plant growth regulator abscisic acid (ABA) were applied to 1-year-old potted Vitis vinifera 'Pinot Noir' and 'Cabernet Sauvignon' vines infected with Xylella fastidiosa, the bacterial pathogen that causes Pierce's disease (PD). A naturally occurring ABA and a synthetic ABA were applied, and both materials showed some effectiveness at increasing curing rates of PD-affected grapevines. Pinot Noir grapevines treated with the drench ABA treatments had significantly greater disease curing effects than the unsprayed control plants. It has been shown that plant phenolics have antimicrobial properties, and we found a positive correlation between effective ABA treatments and the total phenolic compound content of xylem sap extracted from Pinot Noir vines.
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Affiliation(s)
- Melody M Meyer
- Department of Plant Pathology, University of California, Davis
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104
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Mhedbi-Hajri N, Jacques MA, Koebnik R. Adhesion mechanisms of plant-pathogenic Xanthomonadaceae. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 715:71-89. [PMID: 21557058 DOI: 10.1007/978-94-007-0940-9_5] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The family Xanthomonadaceae is a wide-spread family of bacteria belonging to the gamma subdivision of the Gram-negative proteobacteria, including the two plant-pathogenic genera Xanthomonas and Xylella, and the related genus Stenotrophomonas. Adhesion is a widely conserved virulence mechanism among Gram-negative bacteria, no matter whether they are human, animal or plant pathogens, since attachment to the host tissue is one of the key early steps of the bacterial infection process. Bacterial attachment to surfaces is mediated by surface structures that are anchored in the bacterial outer membrane and cover a broad group of fimbrial and non-fimbrial structures, commonly known as adhesins. In this chapter, we discuss recent findings on candidate adhesins of plant-pathogenic Xanthomonadaceae, including polysaccharidic (lipopolysaccharides, exopolysaccharides) and proteineous structures (chaperone/usher pili, type IV pili, autotransporters, two-partner-secreted and other outer membrane adhesins), their involvement in the formation of biofilms and their mode of regulation via quorum sensing. We then compare the arsenals of adhesins among different Xanthomonas strains and evaluate their mode of selection. Finally, we summarize the sparse knowledge on specific adhesin receptors in plants and the possible role of RGD motifs in binding to integrin-like plant molecules.
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Affiliation(s)
- Nadia Mhedbi-Hajri
- Pathologie Végétale (UMR077 INRA-Agrocampus Ouest-Université d'Angers), Beaucouzé, France.
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105
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Chatterjee S, Killiny N, Almeida RPP, Lindow SE. Role of cyclic di-GMP in Xylella fastidiosa biofilm formation, plant virulence, and insect transmission. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:1356-1363. [PMID: 20831412 DOI: 10.1094/mpmi-03-10-0057] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Xylella fastidiosa must coordinately regulate a variety of traits contributing to biofilm formation, host plant and vector colonization, and transmission between plants. Traits such as production of extracellular polysaccharides (EPS), adhesins, extracellular enzymes, and pili are expressed in a cell-density-dependent fashion mediated by a cell-to-cell signaling system involving a fatty acid diffusible signaling factor (DSF). The expression of gene PD0279 (which has a GGDEF domain) is downregulated in the presence of DSF and may be involved in intracellular signaling by modulating the levels of cyclic di-GMP. PD0279, designated cyclic di-GMP synthase A (cgsA), is required for biofilm formation, plant virulence, and vector transmission. cgsA mutants exhibited a hyperadhesive phenotype in vitro and overexpressed gumJ, hxfA, hxfB, xadA, and fimA, which promote attachment of cells to surfaces and, hence, biofilm formation. The mutants were greatly reduced in virulence to grape albeit still transmissible by insect vectors, although at a reduced level compared with transmission rates of the wild-type strain, despite the fact that similar numbers of cells of the cgsA mutant were acquired by the insects from infected plants. High levels of EPS were measured in cgsA mutants compared with wild-type strains, and scanning electron microscopy analysis also revealed a thicker amorphous layer surrounding the mutants. Overexpression of cgsA in a cgsA-complemented mutant conferred the opposite phenotypes in vitro. These results suggest that decreases of cyclic di-GMP result from the accumulation of DSF as cell density increases, leading to a phenotypic transition from a planktonic state capable of colonizing host plants to an adhesive state that is insect transmissible.
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Affiliation(s)
- Subhadeep Chatterjee
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
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106
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Caserta R, Takita MA, Targon ML, Rosselli-Murai LK, de Souza AP, Peroni L, Stach-Machado DR, Andrade A, Labate CA, Kitajima EW, Machado MA, de Souza AA. Expression of Xylella fastidiosa fimbrial and afimbrial proteins during biofilm formation. Appl Environ Microbiol 2010; 76:4250-9. [PMID: 20472735 PMCID: PMC2897468 DOI: 10.1128/aem.02114-09] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Accepted: 05/04/2010] [Indexed: 11/20/2022] Open
Abstract
Complete sequencing of the Xylella fastidiosa genome revealed characteristics that have not been described previously for a phytopathogen. One characteristic of this genome was the abundance of genes encoding proteins with adhesion functions related to biofilm formation, an essential step for colonization of a plant host or an insect vector. We examined four of the proteins belonging to this class encoded by genes in the genome of X. fastidiosa: the PilA2 and PilC fimbrial proteins, which are components of the type IV pili, and XadA1 and XadA2, which are afimbrial adhesins. Polyclonal antibodies were raised against these four proteins, and their behavior during biofilm development was assessed by Western blotting and immunofluorescence assays. In addition, immunogold electron microscopy was used to detect these proteins in bacteria present in xylem vessels of three different hosts (citrus, periwinkle, and hibiscus). We verified that these proteins are present in X. fastidiosa biofilms but have differential regulation since the amounts varied temporally during biofilm formation, as well as spatially within the biofilms. The proteins were also detected in bacteria colonizing the xylem vessels of infected plants.
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Affiliation(s)
- R. Caserta
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
| | - M. A. Takita
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
| | - M. L. Targon
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
| | - L. K. Rosselli-Murai
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
| | - A. P. de Souza
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
| | - L. Peroni
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
| | - D. R. Stach-Machado
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
| | - A. Andrade
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
| | - C. A. Labate
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
| | - E. W. Kitajima
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
| | - M. A. Machado
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
| | - A. A. de Souza
- Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis SP, Brazil 13490-970, Universidade Estadual de Campinas/UNICAMP, Centro de Biologia Molecular e Engenharia Genética, Departamento de Genética e Evolução, Instituto de Biologia, P.O. Box 6010, Campinas SP, Brazil 13083-970, Universidade Estadual de Campinas/UNICAMP, Laboratório de Imunologia Aplicada, Departamento de Microbiologia e Imunologia, Rua Monteiro Lobato s/n, Campinas SP, Brazil 13083-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Laboratório Max Feffer de Genética de Plantas, Departamento de Genética, P.O. Box 83, Piracicaba SP, Brazil 13400-970, Escola Superior de Agricultura “Luiz de Queiroz”/USP, Núcleo de Apoio à Pesquisa em Microscopia Eletrônica Aplicada à Pesquisa Agropecuária (NAP/MEPA), Piracicaba SP, Brazil 13418-900
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Riggio MP, Dempsey KE, Lennon A, Allan D, Ramage G, Bagg J. Molecular detection of transcriptionally active bacteria from failed prosthetic hip joints removed during revision arthroplasty. Eur J Clin Microbiol Infect Dis 2010; 29:823-34. [PMID: 20449620 DOI: 10.1007/s10096-010-0934-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 04/03/2010] [Indexed: 10/19/2022]
Abstract
The purpose of this study was to use microbiological culture and bacterial 16S rRNA gene sequencing methods to detect transcriptionally active bacteria present on the surface of failed prosthetic hip joints removed during revision arthroplasty. Five failed prosthetic hip joints were sonicated to dislodge adherent bacteria and subjected to microbiological culture. Bacterial RNA was extracted from each sonicate, cDNA prepared by reverse transcription and the 16S rRNA gene amplified using universal primers. Polymerase chain reaction (PCR) products were cloned, assigned to distinct groups by restriction fragment length polymorphism (RFLP) analysis and one representative clone from each group was sequenced. Bacteria were identified by comparison of the obtained 16S rRNA gene sequences with those deposited in public access sequence databases. All five specimens were positive for the presence of bacteria by both culture and PCR. Culture methods identified species from eight genera. Molecular detection of transcriptionally active bacteria identified a wider range of species. A total of 42 phylotypes were identified, of which Lysobacter gummosus was the most abundant (31.6%). Thirty-four clones (14.5%) represented uncultivable phylotypes. No potentially novel species were identified. It is concluded that a diverse range of transcriptionally active bacterial species are present within biofilms on the surface of failed prosthetic hip joints.
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Affiliation(s)
- M P Riggio
- Infection and Immunity Research Group, Level 9, Glasgow Dental Hospital & School, 378 Sauchiehall Street, Glasgow G2 3JZ, UK.
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108
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Fogaça AC, Zaini PA, Wulff NA, da Silva PIP, Fázio MA, Miranda A, Daffre S, da Silva AM. Effects of the antimicrobial peptide gomesin on the global gene expression profile, virulence and biofilm formation of Xylella fastidiosa. FEMS Microbiol Lett 2010; 306:152-9. [PMID: 20370836 DOI: 10.1111/j.1574-6968.2010.01950.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
In the xylem vessels of susceptible hosts, such as citrus trees, Xylella fastidiosa forms biofilm-like colonies that can block water transport, which appears to correlate to disease symptoms. Besides aiding host colonization, bacterial biofilms play an important role in resistance against antimicrobial agents, for instance antimicrobial peptides (AMPs). Here, we show that gomesin, a potent AMP from a tarantula spider, modulates X. fastidiosa gene expression profile upon 60 min of treatment with a sublethal concentration. DNA microarray hybridizations revealed that among the upregulated coding sequences, some are related to biofilm production. In addition, we show that the biofilm formed by gomesin-treated bacteria is thicker than that formed by nontreated cells or cells exposed to streptomycin. We have also observed that the treatment of X. fastidiosa with a sublethal concentration of gomesin before inoculation in tobacco plants correlates with a reduction in foliar symptoms, an effect possibly due to the trapping of bacterial cells to fewer xylem vessels, given the enhancement in biofilm production. These results warrant further investigation of how X. fastidiosa would respond to the AMPs produced by citrus endophytes and by the insect vector, leading to a better understanding of the mechanism of action of these molecules on bacterial virulence.
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Affiliation(s)
- Andréa C Fogaça
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, SP, Brazil
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109
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Green S, Studholme DJ, Laue BE, Dorati F, Lovell H, Arnold D, Cottrell JE, Bridgett S, Blaxter M, Huitema E, Thwaites R, Sharp PM, Jackson RW, Kamoun S. Comparative genome analysis provides insights into the evolution and adaptation of Pseudomonas syringae pv. aesculi on Aesculus hippocastanum. PLoS One 2010; 5:e10224. [PMID: 20419105 PMCID: PMC2856684 DOI: 10.1371/journal.pone.0010224] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Accepted: 03/26/2010] [Indexed: 11/19/2022] Open
Abstract
A recently emerging bleeding canker disease, caused by Pseudomonas syringae pathovar aesculi (Pae), is threatening European horse chestnut in northwest Europe. Very little is known about the origin and biology of this new disease. We used the nucleotide sequences of seven commonly used marker genes to investigate the phylogeny of three strains isolated recently from bleeding stem cankers on European horse chestnut in Britain (E-Pae). On the basis of these sequences alone, the E-Pae strains were identical to the Pae type-strain (I-Pae), isolated from leaf spots on Indian horse chestnut in India in 1969. The phylogenetic analyses also showed that Pae belongs to a distinct clade of P. syringae pathovars adapted to woody hosts. We generated genome-wide Illumina sequence data from the three E-Pae strains and one strain of I-Pae. Comparative genomic analyses revealed pathovar-specific genomic regions in Pae potentially implicated in virulence on a tree host, including genes for the catabolism of plant-derived aromatic compounds and enterobactin synthesis. Several gene clusters displayed intra-pathovar variation, including those encoding type IV secretion, a novel fatty acid biosynthesis pathway and a sucrose uptake pathway. Rates of single nucleotide polymorphisms in the four Pae genomes indicate that the three E-Pae strains diverged from each other much more recently than they diverged from I-Pae. The very low genetic diversity among the three geographically distinct E-Pae strains suggests that they originate from a single, recent introduction into Britain, thus highlighting the serious environmental risks posed by the spread of an exotic plant pathogenic bacterium to a new geographic location. The genomic regions in Pae that are absent from other P. syringae pathovars that infect herbaceous hosts may represent candidate genetic adaptations to infection of the woody parts of the tree.
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Affiliation(s)
- Sarah Green
- Centre for Forestry and Climate Change, Forest Research, Roslin, Midlothian, United Kingdom.
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110
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Moreira LM, Almeida NF, Potnis N, Digiampietri LA, Adi SS, Bortolossi JC, da Silva AC, da Silva AM, de Moraes FE, de Oliveira JC, de Souza RF, Facincani AP, Ferraz AL, Ferro MI, Furlan LR, Gimenez DF, Jones JB, Kitajima EW, Laia ML, Leite RP, Nishiyama MY, Rodrigues Neto J, Nociti LA, Norman DJ, Ostroski EH, Pereira HA, Staskawicz BJ, Tezza RI, Ferro JA, Vinatzer BA, Setubal JC. Novel insights into the genomic basis of citrus canker based on the genome sequences of two strains of Xanthomonas fuscans subsp. aurantifolii. BMC Genomics 2010; 11:238. [PMID: 20388224 PMCID: PMC2883993 DOI: 10.1186/1471-2164-11-238] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Accepted: 04/13/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Citrus canker is a disease that has severe economic impact on the citrus industry worldwide. There are three types of canker, called A, B, and C. The three types have different phenotypes and affect different citrus species. The causative agent for type A is Xanthomonas citri subsp. citri, whose genome sequence was made available in 2002. Xanthomonas fuscans subsp. aurantifolii strain B causes canker B and Xanthomonas fuscans subsp. aurantifolii strain C causes canker C. RESULTS We have sequenced the genomes of strains B and C to draft status. We have compared their genomic content to X. citri subsp. citri and to other Xanthomonas genomes, with special emphasis on type III secreted effector repertoires. In addition to pthA, already known to be present in all three citrus canker strains, two additional effector genes, xopE3 and xopAI, are also present in all three strains and are both located on the same putative genomic island. These two effector genes, along with one other effector-like gene in the same region, are thus good candidates for being pathogenicity factors on citrus. Numerous gene content differences also exist between the three cankers strains, which can be correlated with their different virulence and host range. Particular attention was placed on the analysis of genes involved in biofilm formation and quorum sensing, type IV secretion, flagellum synthesis and motility, lipopolysacharide synthesis, and on the gene xacPNP, which codes for a natriuretic protein. CONCLUSION We have uncovered numerous commonalities and differences in gene content between the genomes of the pathogenic agents causing citrus canker A, B, and C and other Xanthomonas genomes. Molecular genetics can now be employed to determine the role of these genes in plant-microbe interactions. The gained knowledge will be instrumental for improving citrus canker control.
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Affiliation(s)
- Leandro M Moreira
- Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Campus Morro do Cruzeiro, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Nalvo F Almeida
- Faculdade de Computação, Universidade Federal do Mato Grosso do Sul, Campo Grande, MS, Brazil
| | - Neha Potnis
- Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| | - Luciano A Digiampietri
- Escola de Artes, Ciências, e Humanidades, Universidade de São Paulo, São Paulo, SP, Brazil
- Laboratório de Bioinformática, Instituto de Computação, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Said S Adi
- Faculdade de Computação, Universidade Federal do Mato Grosso do Sul, Campo Grande, MS, Brazil
| | - Julio C Bortolossi
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
| | | | - Aline M da Silva
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Fabrício E de Moraes
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
| | - Julio C de Oliveira
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
- Departamento de Ciências Biológicas, Campus de Diadema, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Robson F de Souza
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Agda P Facincani
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
| | - André L Ferraz
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
| | - Maria I Ferro
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
| | - Luiz R Furlan
- Departamento de Melhoramento e Nutrição Animal, Faculdade de Medicina Veterinária e Zootecnia de Botucatu, UNESP - Univ. Estadual Paulista, SP, Brazil
| | - Daniele F Gimenez
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
| | - Jeffrey B Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| | - Elliot W Kitajima
- Núcleo de apoio à pesquisa em microscopia eletrônica aplicada à pesquisa agropecuária, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - Marcelo L Laia
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
- Departamento de Engenharia Florestal, Centro de Ciências Agroveterinárias, Universidade do Estado de Santa Catarina, Lages, SC, Brazil
| | - Rui P Leite
- Instituto Agronômico do Paraná, Londrina, PR, Brazil
| | - Milton Y Nishiyama
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Julio Rodrigues Neto
- Laboratório de Bacteriologia Vegetal, Instituto Biológico Campinas, Campinas, SP, Brazil
| | - Letícia A Nociti
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
| | - David J Norman
- Institute of Food and Agricultural Sciences, Mid-Florida Research & Education Center, University of Florida, Gainesville, FL, USA
| | - Eric H Ostroski
- Laboratório de Bioinformática, Instituto de Computação, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Haroldo A Pereira
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
| | - Brian J Staskawicz
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Renata I Tezza
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
| | - Jesus A Ferro
- Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil
| | - Boris A Vinatzer
- Department of Plant Pathology, Physiology and Weed Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - João C Setubal
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
- Department of Computer Science, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
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111
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Voegel TM, Warren JG, Matsumoto A, Igo MM, Kirkpatrick BC. Localization and characterization of Xylella fastidiosa haemagglutinin adhesins. MICROBIOLOGY-SGM 2010; 156:2172-2179. [PMID: 20378647 DOI: 10.1099/mic.0.037564-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Xylella fastidiosa is a gram-negative, xylem-inhabiting, plant-pathogenic bacterium responsible for several important diseases including Pierce's disease (PD) of grapevines. The bacteria form biofilms in grapevine xylem that contribute to the occlusion of the xylem vessels. X. fastidiosa haemagglutinin (HA) proteins are large afimbrial adhesins that have been shown to be crucial for biofilm formation. Little is known about the mechanism of X. fastidiosa HA-mediated cell-cell aggregation or the localization of the adhesins on the cell. We generated anti-HA antibodies and show that X. fastidiosa HAs are present in the outer membrane and secreted both as soluble proteins and in membrane vesicles. Furthermore, the HA pre-proteins are processed from the predicted molecular mass of 360 kDa to a mature 220 kDa protein. Based on this information, we are evaluating a novel form of potential resistance against PD by generating HA-expressing transgenic grapevines.
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Affiliation(s)
- Tanja M Voegel
- Department of Plant Pathology, University of California, Davis, CA 951616, USA
- Center for Applied Biosciences, University of Freiburg, Germany
| | - Jeremy G Warren
- Department of Plant Pathology, University of California, Davis, CA 951616, USA
| | - Ayumi Matsumoto
- Department of Microbiology, University of California, Davis, CA 951616, USA
| | - Michele M Igo
- Department of Microbiology, University of California, Davis, CA 951616, USA
| | - Bruce C Kirkpatrick
- Department of Plant Pathology, University of California, Davis, CA 951616, USA
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112
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Killiny N, Almeida RPP. Host structural carbohydrate induces vector transmission of a bacterial plant pathogen. Proc Natl Acad Sci U S A 2009; 106:22416-20. [PMID: 20018775 PMCID: PMC2794033 DOI: 10.1073/pnas.0908562106] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Indexed: 01/26/2023] Open
Abstract
Many insect-borne pathogens have complex life histories because they must colonize both hosts and vectors for successful dissemination. In addition, the transition from host to vector environments may require changes in gene expression before the pathogen's departure from the host. Xylella fastidiosa is a xylem-limited plant-pathogenic bacterium transmitted by leafhopper vectors that causes diseases in a number of economically important plants. We hypothesized that factors of host origin, such as plant structural polysaccharides, are important in regulating X. fastidiosa gene expression and mediating vector transmission of this pathogen. The addition of pectin and glucan to a simple defined medium resulted in dramatic changes in X. fastidiosa's phenotype and gene-expression profile. Cells grown in the presence of pectin became more adhesive than in other media tested. In addition, the presence of pectin and glucan in media resulted in significant changes in the expression of several genes previously identified as important for X. fastidiosa's pathogenicity in plants. Furthermore, vector transmission of X. fastidiosa was induced in the presence of both polysaccharides. Our data show that host structural polysaccharides mediate gene regulation in X. fastidiosa, which results in phenotypic changes required for vector transmission. A better understanding of how vector-borne pathogens transition from host to vector, and vice versa, may lead to previously undiscovered disease-control strategies.
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Affiliation(s)
- Nabil Killiny
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720
| | - Rodrigo P. P. Almeida
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720
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113
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Ryan RP, Monchy S, Cardinale M, Taghavi S, Crossman L, Avison MB, Berg G, van der Lelie D, Dow JM. The versatility and adaptation of bacteria from the genus Stenotrophomonas. Nat Rev Microbiol 2009; 7:514-25. [PMID: 19528958 DOI: 10.1038/nrmicro2163] [Citation(s) in RCA: 453] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The genus Stenotrophomonas comprises at least eight species. These bacteria are found throughout the environment, particularly in close association with plants. Strains of the most predominant species, Stenotrophomonas maltophilia, have an extraordinary range of activities that include beneficial effects for plant growth and health, the breakdown of natural and man-made pollutants that are central to bioremediation and phytoremediation strategies and the production of biomolecules of economic value, as well as detrimental effects, such as multidrug resistance, in human pathogenic strains. Here, we discuss the versatility of the bacteria in the genus Stenotrophomonas and the insight that comparative genomic analysis of clinical and endophytic isolates of S. maltophilia has brought to our understanding of the adaptation of this genus to various niches.
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Affiliation(s)
- Robert P Ryan
- BIOMERIT Research Centre, Department of Microbiology, BioSciences Institute, University College Cork, Cork, Ireland.
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114
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Darsonval A, Darrasse A, Durand K, Bureau C, Cesbron S, Jacques MA. Adhesion and fitness in the bean phyllosphere and transmission to seed of Xanthomonas fuscans subsp. fuscans. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2009; 22:747-57. [PMID: 19445599 DOI: 10.1094/mpmi-22-6-0747] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Deciphering the mechanisms enabling plant-pathogenic bacteria to disperse, colonize, and survive on their hosts provides the necessary basis to set up new control methods. We evaluated the role of bacterial attachment and biofilm formation in host colonization processes for Xanthomonas fuscans subsp. fuscans on its host. This bacterium is responsible for the common bacterial blight of bean (Phaseolus vulgaris), a seedborne disease. The five adhesin genes (pilA, fhab, xadA1, xadA2, and yapH) identified in X. fuscans subsp. fuscans CFBP4834-R strain were mutated. All mutants were altered in their abilities to adhere to polypropylene or seed. PilA was involved in adhesion and transmission to seed, and mutation of pilA led to lower pathogenicity on bean. YapH was required for adhesion to seed, leaves, and abiotic surfaces but not for in planta transmission to seed or aggressiveness on leaves. Transmission to seed through floral structures did not require any of the known adhesins. Conversely, all mutants tested, except in yapH, were altered in their vascular transmission to seed. In conclusion, we showed that adhesins are implicated in the various processes leading to host phyllosphere colonization and transmission to seed by plant-pathogenic bacteria.
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Affiliation(s)
- A Darsonval
- UMR077 PaVé, INRA, 42, F-49071 Beaucouzé, France
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115
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Shi XY, Dumenyo CK, Hernandez-Martinez R, Azad H, Cooksey DA. Characterization of regulatory pathways in Xylella fastidiosa: genes and phenotypes controlled by gacA. Appl Environ Microbiol 2009; 75:2275-83. [PMID: 19218414 PMCID: PMC2675201 DOI: 10.1128/aem.01964-08] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2008] [Accepted: 02/03/2009] [Indexed: 11/20/2022] Open
Abstract
The xylem-limited, insect-transmitted bacterium Xylella fastidiosa causes Pierce's disease in grapes through cell aggregation and vascular clogging. GacA controls various physiological processes and pathogenicity factors in many gram-negative bacteria, including biofilm formation in Pseudomonas syringae pv. tomato DC3000. Cloned gacA of X. fastidiosa was found to restore the hypersensitive response and pathogenicity in gacA mutants of P. syringae pv. tomato DC3000 and Erwinia amylovora. A gacA mutant of X. fastidiosa (DAC1984) had significantly reduced abilities to adhere to a glass surface, form biofilm, and incite disease symptoms on grapevines, compared with the parent (A05). cDNA microarray analysis identified 7 genes that were positively regulated by GacA, including xadA and hsf, predicted to encode outer membrane adhesion proteins, and 20 negatively regulated genes, including gumC and an antibacterial polypeptide toxin gene, cvaC. These results suggest that GacA of X. fastidiosa regulates many factors, which contribute to attachment and biofilm formation, as well as some physiological processes that may enhance the adaptation and tolerance of X. fastidiosa to environmental stresses and the competition within the host xylem.
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Affiliation(s)
- Xiang Yang Shi
- Department of Plant Pathology and Microbiology, University of California, Riverside, California 92521, USA
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116
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Matsumoto A, Young GM, Igo MM. Chromosome-based genetic complementation system for Xylella fastidiosa. Appl Environ Microbiol 2009; 75:1679-87. [PMID: 19151176 PMCID: PMC2655483 DOI: 10.1128/aem.00024-09] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 01/08/2009] [Indexed: 12/18/2022] Open
Abstract
Xylella fastidiosa is a xylem-limited, gram-negative bacterium that causes Pierce's disease of grapevine. Here, we describe the construction of four vectors that facilitate the insertion of genes into a neutral site (NS1) in the X. fastidiosa chromosome. These vectors carry a colE1-like (pMB1) replicon and DNA sequences from NS1 flanking a multiple-cloning site and a resistance marker for one of the following antibiotics: chloramphenicol, erythromycin, gentamicin, or kanamycin. In X. fastidiosa, vectors with colE1-like (pMB1) replicons have been found to result primarily in the recovery of double recombinants rather than single recombinants. Thus, the ease of obtaining double recombinants and the stability of the resulting insertions at NS1 in the absence of selective pressure are the major advantages of this system. Based on in vitro and in planta characterizations, strains carrying insertions within NS1 are indistinguishable from wild-type X. fastidiosa in terms of growth rate, biofilm formation, and pathogenicity. To illustrate the usefulness of this system for complementation analysis, we constructed a strain carrying a mutation in the X. fastidiosa cpeB gene, which is predicted to encode a catalase/peroxidase, and showed that the sensitivity of this mutant to hydrogen peroxide could be overcome by the introduction of a wild-type copy of cpeB at NS1. Thus, this chromosome-based complementation system provides a valuable genetic tool for investigating the role of specific genes in X. fastidiosa cell physiology and virulence.
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Affiliation(s)
- Ayumi Matsumoto
- Department of Microbiology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
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117
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Gottig N, Garavaglia BS, Garofalo CG, Orellano EG, Ottado J. A filamentous hemagglutinin-like protein of Xanthomonas axonopodis pv. citri, the phytopathogen responsible for citrus canker, is involved in bacterial virulence. PLoS One 2009; 4:e4358. [PMID: 19194503 PMCID: PMC2632755 DOI: 10.1371/journal.pone.0004358] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Accepted: 12/29/2008] [Indexed: 11/19/2022] Open
Abstract
Xanthomonas axonopodis pv. citri, the phytopathogen responsible for citrus canker has a number of protein secretion systems and among them, at least one type V protein secretion system belonging to the two-partner secretion pathway. This system is mainly associated to the translocation of large proteins such as adhesins to the outer membrane of several pathogens. Xanthomonas axonopodis pv. citri possess a filamentous hemagglutinin-like protein in close vicinity to its putative transporter protein, XacFhaB and XacFhaC, respectively. Expression analysis indicated that XacFhaB was induced in planta during plant-pathogen interaction. By mutation analysis of XacFhaB and XacFhaC genes we determined that XacFhaB is involved in virulence both in epiphytic and wound inoculations, displaying more dispersed and fewer canker lesions. Unexpectedly, the XacFhaC mutant in the transporter protein produced an intermediate virulence phenotype resembling wild type infection, suggesting that XacFhaB could be secreted by another partner different from XacFhaC. Moreover, XacFhaB mutants showed a general lack of adhesion and were affected in leaf surface attachment and biofilm formation. In agreement with the in planta phenotype, adhesin lacking cells moved faster in swarming plates. Since no hyperflagellation phenotype was observed in this bacteria, the faster movement may be attributed to the lack of cell-to-cell aggregation. Moreover, XacFhaB mutants secreted more exopolysaccharide that in turn may facilitate its motility. Our results suggest that this hemagglutinin-like protein is required for tissue colonization being mainly involved in surface attachment and biofilm formation, and that plant tissue attachment and cell-to-cell aggregation are dependent on the coordinated action of adhesin molecules and exopolysaccharides.
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Affiliation(s)
- Natalia Gottig
- Molecular Biology Division, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Betiana S. Garavaglia
- Molecular Biology Division, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Cecilia G. Garofalo
- Molecular Biology Division, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Elena G. Orellano
- Molecular Biology Division, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Jorgelina Ottado
- Molecular Biology Division, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
- * E-mail:
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118
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Killiny N, Almeida RPP. Xylella fastidiosa afimbrial adhesins mediate cell transmission to plants by leafhopper vectors. Appl Environ Microbiol 2009; 75:521-8. [PMID: 19011051 PMCID: PMC2620726 DOI: 10.1128/aem.01921-08] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Accepted: 11/11/2008] [Indexed: 11/20/2022] Open
Abstract
The interactions between the economically important plant-pathogenic bacterium Xylella fastidiosa and its leafhopper vectors are poorly characterized. We used different approaches to determine how X. fastidiosa cells interact with the cuticular surface of the foreguts of vectors. We demonstrate that X. fastidiosa binds to different polysaccharides with various affinities and that these interactions are mediated by cell surface carbohydrate-binding proteins. In addition, competition assays showed that N-acetylglucosamine inhibits bacterial adhesion to vector foregut extracts and intact wings, demonstrating that attachment to leafhopper surfaces is affected in the presence of specific polysaccharides. In vitro experiments with several X. fastidiosa knockout mutants indicated that hemagglutinin-like proteins are associated with cell adhesion to polysaccharides. These results were confirmed with biological experiments in which hemagglutinin-like protein mutants were transmitted to plants by vectors at lower rates than that of the wild type. Furthermore, although these mutants were defective in adhesion to the cuticle of vectors, their growth rate once attached to leafhoppers was similar to that of the wild type, suggesting that these proteins are important for initial adhesion of X. fastidiosa to leafhoppers. We propose that X. fastidiosa colonization of leafhopper vectors is a complex, stepwise process similar to the formation of biofilms on surfaces.
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Affiliation(s)
- Nabil Killiny
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA
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119
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Chatterjee S, Newman KL, Lindow SE. Cell-to-cell signaling in Xylella fastidiosa suppresses movement and xylem vessel colonization in grape. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2008; 21:1309-15. [PMID: 18785826 DOI: 10.1094/mpmi-21-10-1309] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Cell-to-cell signaling mediated by a fatty acid diffusible signaling factor (DSF) is central to the regulation of the virulence of Xylella fastidiosa. DSF production by X. fastidiosa is dependent on rpfF and, although required for insect colonization, appears to reduce its virulence to grape. To understand what aspects of colonization of grape are controlled by DSF in X. fastidiosa and, thus, those factors that contribute to virulence, we assessed the colonization of grape by a green fluorescent protein-marked rpfF-deficient mutant. The rpfF-deficient mutant was detected at a greater distance from the point of inoculation than the wild-type strain at a given sampling time, and also attained a population size that was up to 100-fold larger than that of the wild-type strain at a given distance from the point of inoculation. Confocal laser-scanning microscopy revealed that approximately 10-fold more vessels in petioles of symptomatic leaves harbored at least some cells of either the wild type or rpfF mutant when compared with asymptomatic leaves and, thus, that disease symptoms were associated with the extent of vessel colonization. Importantly, the rpfF mutant colonized approximately threefold more vessels than the wild-type strain. Although a wide range of colony sizes were observed in vessels colonized by both the wild type and rpfF mutant, the proportion of colonized vessels harboring large numbers of cells was significantly higher in plants inoculated with the rpfF mutant than with the wild-type strain. These studies indicated that the hypervirulence phenotype of the rpfF mutant is due to both a more extensive spread of the pathogen to xylem vessels and unrestrained multiplication within vessels leading to blockage. These results suggest that movement and multiplication of X. fastidiosa in plants are linked, perhaps because cell wall degradation products are a major source of nutrients. Thus, DSF-mediated cell-to-cell signaling, which restricts movement and colonization of X. fastidiosa, may be an adaptation to endophytic growth of the pathogen that prevents the excessive growth of cells in vessels.
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Affiliation(s)
- Subhadeep Chatterjee
- Department of Plant and Microbial Biology, University of California, Berkley 94720, USA
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120
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De La Fuente L, Burr TJ, Hoch HC. Autoaggregation of Xylella fastidiosa cells is influenced by type I and type IV pili. Appl Environ Microbiol 2008; 74:5579-82. [PMID: 18641157 PMCID: PMC2546647 DOI: 10.1128/aem.00995-08] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Accepted: 07/02/2008] [Indexed: 11/20/2022] Open
Abstract
Autoaggregation of widely dispersed Xylella fastidiosa cells into compact cell masses occurred over a period of hours following 7 to 11 days of growth in microfluidic chambers. Studies involving the use of mutants defective in polarly positioned type I (fimA-negative), type IV (pilB-negative), or both type I and IV (fimA- and pilO-negative) pili revealed the importance and role of pili in the autoaggregation process.
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Affiliation(s)
- Leonardo De La Fuente
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University-New York State Agricultural Experiment Station, Geneva, NY 14456, USA
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121
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Dow M. Diversification of the function of cell-to-cell signaling in regulation of virulence within plant pathogenic xanthomonads. Sci Signal 2008; 1:pe23. [PMID: 18506032 DOI: 10.1126/stke.121pe23] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The virulence of plant pathogenic bacteria belonging to the genera Xanthomonas and Xylella depends upon cell-to-cell signaling mediated by the diffusible signal molecule DSF (Diffusible Signaling Factor). Synthesis and perception of the DSF signal require products of the rpf gene cluster. The synthesis of DSF depends on RpfF, whereas the RpfC/RpfG two-component system is implicated in DSF perception and signal transduction. The sensor RpfC acts to negatively regulate synthesis of DSF. In Xanthomonas campestris, mutation of rpfF or rpfC leads to a coordinate down-regulation in synthesis of virulence factors and a reduction in virulence. In contrast, in Xylella fastidiosa, the causal agent of Pierce's disease of grape, mutation of rpfF and rpfC have opposite effects on virulence, with rpfF mutants exhibiting a hypervirulent phenotype. The findings suggest that different xanthomonads have adapted the perception and function of similar types of signaling molecule to fit the specific needs for colonization of different hosts.
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Affiliation(s)
- Max Dow
- BIOMERIT Research Centre, Department of Microbiology, BioSciences Institute, National University of Ireland, Cork, Ireland.
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122
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Chatterjee S, Wistrom C, Lindow SE. A cell-cell signaling sensor is required for virulence and insect transmission of Xylella fastidiosa. Proc Natl Acad Sci U S A 2008; 105:2670-5. [PMID: 18268318 PMCID: PMC2268194 DOI: 10.1073/pnas.0712236105] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2007] [Indexed: 11/18/2022] Open
Abstract
Cell-cell signaling in Xylella fastidiosa, a xylem-colonizing plant pathogenic bacterium, mediated by a fatty acid Diffusible Signaling Factor (DSF), is required to colonize insect vectors and to suppress virulence to grape. Here, we show that a hybrid two-component regulatory protein RpfC is involved in negative regulation of DSF synthesis by RpfF in X. fastidiosa. X. fastidiosa rpfC mutants hyperexpress rpfF and overproduce DSF and are deficient in virulence and movement in the xylem vessels of grape. The expression of the genes encoding the adhesins FimA, HxfA, and HxfB is much higher in rpfC mutants, which also exhibit a hyperattachment phenotype in culture that is associated with their inability to migrate in xylem vessels and cause disease. rpfF mutants deficient in DSF production have the opposite phenotypes for all of these traits. RpfC is also involved in the regulation of other signaling components including rpfG, rpfB, a GGDEF domain protein that may be involved in intracellular signaling by modulating the levels of cyclic-di-GMP, and the virulence factors tolC and pglA required for disease. rpfC mutants are able to colonize the mouthparts of insect vectors and wild-type strains but are not transmitted as efficiently to new host plants, apparently because of their high levels of adhesiveness. Because of the conflicting contributions of adhesiveness and other traits to movement within plants and vectoring to new host plants, X. fastidiosa apparently coordinates these traits in a population-size-dependent fashion involving accumulation of DSF.
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Affiliation(s)
| | - Christina Wistrom
- Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720
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123
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Dempsey KE, Riggio MP, Lennon A, Hannah VE, Ramage G, Allan D, Bagg J. Identification of bacteria on the surface of clinically infected and non-infected prosthetic hip joints removed during revision arthroplasties by 16S rRNA gene sequencing and by microbiological culture. Arthritis Res Ther 2008; 9:R46. [PMID: 17501992 PMCID: PMC2206354 DOI: 10.1186/ar2201] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Accepted: 05/14/2007] [Indexed: 11/23/2022] Open
Abstract
It has been postulated that bacteria attached to the surface of prosthetic hip joints can cause localised inflammation, resulting in failure of the replacement joint. However, diagnosis of infection is difficult with traditional microbiological culture methods, and evidence exists that highly fastidious or non-cultivable organisms have a role in implant infections. The purpose of this study was to use culture and culture-independent methods to detect the bacteria present on the surface of prosthetic hip joints removed during revision arthroplasties. Ten consecutive revisions were performed by two surgeons, which were all clinically and radiologically loose. Five of the hip replacement revision surgeries were performed because of clinical infections and five because of aseptic loosening. Preoperative and perioperative specimens were obtained from each patient and subjected to routine microbiological culture. The prostheses removed from each patient were subjected to mild ultrasonication to dislodge adherent bacteria, followed by aerobic and anaerobic microbiological culture. Bacterial DNA was extracted from each sonicate and the 16S rRNA gene was amplified with the universal primer pair 27f/1387r. All 10 specimens were positive for the presence of bacteria by both culture and PCR. PCR products were then cloned, organised into groups by RFLP analysis and one clone from each group was sequenced. Bacteria were identified by comparison of the 16S rRNA gene sequences obtained with those deposited in public access sequence databases. A total of 512 clones were analysed by RFLP analysis, of which 118 were sequenced. Culture methods identified species from the genera Leifsonia (54.3%), Staphylococcus (21.7%), Proteus (8.7%), Brevundimonas (6.5%), Salibacillus (4.3%), Methylobacterium (2.2%) and Zimmermannella (2.2%). Molecular detection methods identified a more diverse microflora. The predominant genus detected was Lysobacter, representing 312 (60.9%) of 512 clones analysed. In all, 28 phylotypes were identified: Lysobacter enzymogenes was the most abundant phylotype (31.4%), followed by Lysobacter sp. C3 (28.3%), gamma proteobacterium N4-7 (6.6%), Methylobacterium SM4 (4.7%) and Staphylococcus epidermidis (4.7%); 36 clones (7.0%) represented uncultivable phylotypes. We conclude that a diverse range of bacterial species are found within biofilms on the surface of clinically infected and non-infected prosthetic hip joints removed during revision arthroplasties.
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Affiliation(s)
- Kate E Dempsey
- Infection and Immunity Research Group, Level 9, Glasgow Dental Hospital & School, 378 Sauchiehall Street, Glasgow G2 3JZ, UK
| | - Marcello P Riggio
- Infection and Immunity Research Group, Level 9, Glasgow Dental Hospital & School, 378 Sauchiehall Street, Glasgow G2 3JZ, UK
| | - Alan Lennon
- Infection and Immunity Research Group, Level 9, Glasgow Dental Hospital & School, 378 Sauchiehall Street, Glasgow G2 3JZ, UK
| | - Victoria E Hannah
- Infection and Immunity Research Group, Level 9, Glasgow Dental Hospital & School, 378 Sauchiehall Street, Glasgow G2 3JZ, UK
| | - Gordon Ramage
- Infection and Immunity Research Group, Level 9, Glasgow Dental Hospital & School, 378 Sauchiehall Street, Glasgow G2 3JZ, UK
| | - David Allan
- The Queen Elizabeth National Spinal Injuries Unit, Scotland, South Glasgow University Hospitals Division, Southern General Hospital, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Jeremy Bagg
- Infection and Immunity Research Group, Level 9, Glasgow Dental Hospital & School, 378 Sauchiehall Street, Glasgow G2 3JZ, UK
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124
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The iron stimulon of Xylella fastidiosa includes genes for type IV pilus and colicin V-like bacteriocins. J Bacteriol 2008; 190:2368-78. [PMID: 18223091 DOI: 10.1128/jb.01495-07] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Xylella fastidiosa is the etiologic agent of a wide range of plant diseases, including citrus variegated chlorosis (CVC), a major threat to citrus industry. The genomes of several strains of this phytopathogen were completely sequenced, enabling large-scale functional studies. DNA microarrays representing 2,608 (91.6%) coding sequences (CDS) of X. fastidiosa CVC strain 9a5c were used to investigate transcript levels during growth with different iron availabilities. When treated with the iron chelator 2,2'-dipyridyl, 193 CDS were considered up-regulated and 216 were considered down-regulated. Upon incubation with 100 microM ferric pyrophosphate, 218 and 256 CDS were considered up- and down-regulated, respectively. Differential expression for a subset of 44 CDS was further evaluated by reverse transcription-quantitative PCR. Several CDS involved with regulatory functions, pathogenicity, and cell structure were modulated under both conditions assayed, suggesting that major changes in cell architecture and metabolism occur when X. fastidiosa cells are exposed to extreme variations in iron concentration. Interestingly, the modulated CDS include those related to colicin V-like bacteriocin synthesis and secretion and to functions of pili/fimbriae. We also investigated the contribution of the ferric uptake regulator Fur to the iron stimulon of X. fastidiosa. The promoter regions of the strain 9a5c genome were screened for putative Fur boxes, and candidates were analyzed by electrophoretic mobility shift assays. Taken together, our data support the hypothesis that Fur is not solely responsible for the modulation of the iron stimulon of X. fastidiosa, and they present novel evidence for iron regulation of pathogenicity determinants.
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125
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Chatterjee S, Almeida RPP, Lindow S. Living in two worlds: the plant and insect lifestyles of Xylella fastidiosa. ANNUAL REVIEW OF PHYTOPATHOLOGY 2008; 46:243-71. [PMID: 18422428 DOI: 10.1146/annurev.phyto.45.062806.094342] [Citation(s) in RCA: 241] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Diseases caused by Xylella fastidiosa have attained great importance worldwide as the pathogen and its insect vectors have been disseminated. Since this is the first plant pathogenic bacterium for which a complete genome sequence was determined, much progress has been made in understanding the process by which it spreads within the xylem vessels of susceptible plants as well as the traits that contribute to its acquisition and transmission by sharpshooter vectors. Although this pathogen shares many similarities with Xanthomonas species, such as its use of a small fatty acid signal molecule to coordinate virulence gene expression, the traits that it utilizes to cause disease and the manner in which they are regulated differ substantially from those of related plant pathogens. Its complex lifestyle as both a plant and insect colonist involves traits that are in conflict with these stages, thus apparently necessitating the use of a gene regulatory scheme that allows cells expressing different traits to co-occur in the plant.
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Affiliation(s)
- Subhadeep Chatterjee
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA.
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126
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Francis M, Civerolo EL, Bruening G. Improved Bioassay of Xylella fastidiosa Using Nicotiana tabacum Cultivar SR1. PLANT DISEASE 2008; 92:14-20. [PMID: 30786389 DOI: 10.1094/pdis-92-1-0014] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Readily transformable Nicotiana tabacum cv. SR1 (Petite Havana) was evaluated as a host for the bioassay of Xylella fastidiosa strains. Plant growing conditions and inoculation methods were optimized to enhance symptom expression 4 to 6 weeks post inoculation. Tobacco plants were inoculated with X. fastidiosa strains associated with almond leaf scorch disease (ALSD) and Pierce's disease (PD) of grapevine in California. All PD strains and the ALSD strain Dixon caused characteristic leaf scorch symptoms, whereas two other ALSD-associated strains (M12 and M23) caused severe leaf chlorosis followed by necrosis, leaf death, and drooping of older leaves. Symptoms began to develop 10 to 14 days post inoculation and proceeded to resemble those of X. fastidiosa-infected grape and almond. The presence of X. fastidiosa in affected plants was confirmed by reisolation of the pathogen, enzyme-linked immunosorbent assay, quantitative polymerase chain reaction (QPCR), and observation of X. fastidiosa cells by transmission and scanning electron microscopy, as well as by confocal laser scanning microscopy, in the xylem cells of inoculated plants. The pathogenicity of selected reisolated strains was confirmed by inoculation of grape plants in the greenhouse. The average levels of X. fastidiosa cells/g of tissue, estimated by QPCR, were higher for PD strains than for ALSD strains and reflected the relative titers of these strains in economic hosts. No symptoms were observed and bacteria were not detected in untreated tobacco or in tobacco inoculated with Xanthomonas campestris pv. campestris or water. Symptoms induced by Xylella fastidiosa in this bioassay were fully expressed within 2 months following inoculation. The described bioassay, under optimized environmental conditions, provides a useful system for studying X. fastidiosa strains (e.g., confirmation of pathogenicity and differentiation of PD and ALSD pathotypes) and for investigating X. fastidiosa-host interactions. N. tabacum cv. SR1 tobacco was a better bioassay host for X. fastidiosa than N. tabacum cvs. Havana, RP1, and TNN described previously.
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Affiliation(s)
- M Francis
- University of California, Department of Plant Pathology, Davis 95616
| | - E L Civerolo
- United States Department of Agriculture-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
| | - G Bruening
- University of California, Department of Plant Pathology, Davis
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127
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Abstract
Plants support a diverse array of bacteria, including parasites, mutualists, and commensals on and around their roots, in the vasculature, and on aerial tissues. These microbes have a profound influence on plant health and productivity. Bacteria physically interact with surfaces to form complex multicellular and often multispecies assemblies, including biofilms and smaller aggregates. There is growing appreciation that the intensity, duration, and outcome of plant-microbe interactions are significantly influenced by the conformation of adherent microbial populations. Biofilms on different tissues have unique properties, reflecting the prevailing conditions at those sites. Attachment is required for biofilm formation, and bacteria interact with plant tissues through adhesins including polysaccharides and surface proteins, with initial contact often mediated by active motility. Recognition between lectins and their cognate carbohydrates is a common means of specificity. Biofilm development and the resulting intimate interactions with plants often require cell-cell communication between colonizing bacteria.
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Affiliation(s)
- Thomas Danhorn
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
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128
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da Silva Neto JF, Koide T, Abe CM, Gomes SL, Marques MV. Role of sigma54 in the regulation of genes involved in type I and type IV pili biogenesis in Xylella fastidiosa. Arch Microbiol 2007; 189:249-61. [PMID: 17985115 DOI: 10.1007/s00203-007-0314-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Revised: 10/05/2007] [Accepted: 10/15/2007] [Indexed: 11/30/2022]
Abstract
The phytopathogen Xylella fastidiosa produces long type IV pili and short type I pili involved in motility and adhesion. In this work, we have investigated the role of sigma factor sigma(54) (RpoN) in the regulation of fimbrial biogenesis in X. fastidiosa. An rpoN null mutant was constructed from the non-pathogenic citrus strain J1a12, and microarray analyses of global gene expression comparing the wild type and rpoN mutant strains showed few genes exhibiting differential expression. In particular, gene pilA1 (XF2542), which encodes the structural pilin protein of type IV pili, showed decreased expression in the rpoN mutant, whereas two-fold higher expression of an operon encoding proteins of type I pili was detected, as confirmed by quantitative RT-PCR (qRT-PCR) analysis. The transcriptional start site of pilA1 was determined by primer extension, downstream of a sigma(54)-dependent promoter. Microarray and qRT-PCR data demonstrated that expression of only one of the five pilA paralogues, pilA1, was significantly reduced in the rpoN mutant. The rpoN mutant made more biofilm than the wild type strain and presented a cell-cell aggregative phenotype. These results indicate that sigma(54) differentially regulates genes involved in type IV and type I fimbrial biogenesis, and is involved in biofilm formation in X. fastidiosa.
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Affiliation(s)
- José F da Silva Neto
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1374, 05508-000 São Paulo, SP, Brazil
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129
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Shi XY, Dumenyo CK, Hernandez-Martinez R, Azad H, Cooksey DA. Characterization of regulatory pathways in Xylella fastidiosa: genes and phenotypes controlled by algU. Appl Environ Microbiol 2007; 73:6748-56. [PMID: 17827317 PMCID: PMC2074953 DOI: 10.1128/aem.01232-07] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2007] [Accepted: 08/29/2007] [Indexed: 11/20/2022] Open
Abstract
Many virulence genes in plant bacterial pathogens are coordinately regulated by "global" regulatory genes. Conducting DNA microarray analysis of bacterial mutants of such genes, compared with the wild type, can help to refine the list of genes that may contribute to virulence in bacterial pathogens. The regulatory gene algU, with roles in stress response and regulation of the biosynthesis of the exopolysaccharide alginate in Pseudomonas aeruginosa and many other bacteria, has been extensively studied. The role of algU in Xylella fastidiosa, the cause of Pierce's disease of grapevines, was analyzed by mutation and whole-genome microarray analysis to define its involvement in aggregation, biofilm formation, and virulence. In this study, an algU::nptII mutant had reduced cell-cell aggregation, attachment, and biofilm formation and lower virulence in grapevines. Microarray analysis showed that 42 genes had significantly lower expression in the algU::nptII mutant than in the wild type. Among these are several genes that could contribute to cell aggregation and biofilm formation, as well as other physiological processes such as virulence, competition, and survival.
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Affiliation(s)
- Xiang Yang Shi
- Department of Plant Pathology and Microbiology, University of California, 900 University Avenue, Riverside, CA 92521, USA
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130
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Roper MC, Greve LC, Labavitch JM, Kirkpatrick BC. Detection and visualization of an exopolysaccharide produced by Xylella fastidiosa in vitro and in planta. Appl Environ Microbiol 2007; 73:7252-8. [PMID: 17827325 PMCID: PMC2168192 DOI: 10.1128/aem.00895-07] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Accepted: 08/29/2007] [Indexed: 11/20/2022] Open
Abstract
Many phytopathogenic bacteria, such as Ralstonia solanacearum, Pantoea stewartii, and Xanthomonas campestris, produce exopolysaccharides (EPSs) that aid in virulence, colonization, and survival. EPS can also contribute to host xylem vessel blockage. The genome of Xylella fastidiosa, the causal agent of Pierce's disease (PD) of grapevine, contains an operon that is strikingly similar to the X. campestris gum operon, which is responsible for the production of xanthan gum. Based on this information, it has been hypothesized that X. fastidiosa is capable of producing an EPS similar in structure and composition to xanthan gum but lacking the terminal mannose residue. In this study, we raised polyclonal antibodies against a modified xanthan gum polymer similar to the predicted X. fastidiosa EPS polymer. We used enzyme-linked immunosorbent assay to quantify production of EPS from X. fastidiosa cells grown in vitro and immunolocalization microscopy to examine the distribution of X. fastidiosa EPS in biofilms formed in vitro and in planta and assessed the contribution of X. fastidiosa EPS to the vascular occlusions seen in PD-infected grapevines.
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Affiliation(s)
- M Caroline Roper
- Department of Plant Pathology, University of California, Davis, Davis, CA 95616, USA
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131
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Barbosa RL, Benedetti CE. BigR, a transcriptional repressor from plant-associated bacteria, regulates an operon implicated in biofilm growth. J Bacteriol 2007; 189:6185-94. [PMID: 17586627 PMCID: PMC1951920 DOI: 10.1128/jb.00331-07] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Accepted: 06/15/2007] [Indexed: 11/20/2022] Open
Abstract
Xylella fastidiosa is a plant pathogen that colonizes the xylem vessels, causing vascular occlusion due to bacterial biofilm growth. However, little is known about the molecular mechanisms driving biofilm formation in Xylella-plant interactions. Here we show that BigR (for "biofilm growth-associated repressor") is a novel helix-turn-helix repressor that controls the transcription of an operon implicated in biofilm growth. This operon, which encodes BigR, membrane proteins, and an unusual beta-lactamase-like hydrolase (BLH), is restricted to a few plant-associated bacteria, and thus, we sought to understand its regulation and function in X. fastidiosa and Agrobacterium tumefaciens. BigR binds to a palindromic AT-rich element (the BigR box) in the Xylella and Agrobacterium blh promoters and strongly represses the transcription of the operon in these cells. The BigR box overlaps with two alternative -10 regions identified in the blh promoters, and mutations in this box significantly affected transcription, indicating that BigR competes with the RNA polymerase for the same promoter site. Although BigR is similar to members of the ArsR/SmtB family of regulators, our data suggest that, in contrast to the initial prediction, it does not act as a metal sensor. Increased activity of the BigR operon was observed in both Xylella and Agrobacterium biofilms. In addition, an A. tumefaciens bigR mutant showed constitutive expression of operon genes and increased biofilm formation on glass surfaces and tobacco roots, indicating that the operon may play a role in cell adherence or biofilm development.
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Affiliation(s)
- Rosicler L Barbosa
- Centro de Biologia Molecular Estrutural, Laboratório Nacional de Luz Síncrotron, R. Giuseppe Máximo Scolfaro, 10000, Campinas, São Paulo, CP6192, CEP 13084-971, Brazil
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132
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Li Y, Hao G, Galvani CD, Meng Y, Fuente LDL, Hoch HC, Burr TJ. Type I and type IV pili of Xylella fastidiosa affect twitching motility, biofilm formation and cell-cell aggregation. MICROBIOLOGY-SGM 2007; 153:719-726. [PMID: 17322192 DOI: 10.1099/mic.0.2006/002311-0] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Xylella fastidiosa, an important phytopathogenic bacterium, causes serious plant diseases including Pierce's disease of grapevine. It is reported here that type I and type IV pili of X. fastidiosa play different roles in twitching motility, biofilm formation and cell-cell aggregation. Type I pili are particularly important for biofilm formation and aggregation, whereas type IV pili are essential for motility, and also function in biofilm formation. Thirty twitching-defective mutants were generated with an EZ : : TN transposome system, and several type-IV-pilus-associated genes were identified, including fimT, pilX, pilY1, pilO and pilR. Mutations in fimT, pilX, pilO or pilR resulted in a twitch-minus phenotype, whereas the pilY1 mutant was twitching reduced. A mutation in fimA resulted in a biofilm-defective and twitching-enhanced phenotype. A fimA/pilO double mutant was twitch minus, and produced almost no visible biofilm. Transmission electron microscopy revealed that the pili, when present, were localized to one pole of the cell. Both type I and type IV pili were present in the wild-type isolate and the pilY1 mutant, whereas only type I pili were present in the twitch-minus mutants. The fimA mutant produced no type I pili. The fimA/pilO double mutant produced neither type I nor type IV pili.
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Affiliation(s)
- Yaxin Li
- Department of Plant Pathology, Cornell University - New York State Agricultural Experiment Station, Geneva, NY 14456, USA
| | - Guixia Hao
- Department of Plant Pathology, Cornell University - New York State Agricultural Experiment Station, Geneva, NY 14456, USA
| | - Cheryl D Galvani
- Department of Plant Pathology, Cornell University - New York State Agricultural Experiment Station, Geneva, NY 14456, USA
| | - Yizhi Meng
- Department of Plant Pathology, Cornell University - New York State Agricultural Experiment Station, Geneva, NY 14456, USA
| | - Leonardo De La Fuente
- Department of Plant Pathology, Cornell University - New York State Agricultural Experiment Station, Geneva, NY 14456, USA
| | - H C Hoch
- Department of Plant Pathology, Cornell University - New York State Agricultural Experiment Station, Geneva, NY 14456, USA
| | - Thomas J Burr
- Department of Plant Pathology, Cornell University - New York State Agricultural Experiment Station, Geneva, NY 14456, USA
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Roper MC, Greve LC, Warren JG, Labavitch JM, Kirkpatrick BC. Xylella fastidiosa requires polygalacturonase for colonization and pathogenicity in Vitis vinifera grapevines. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2007; 20:411-9. [PMID: 17427811 DOI: 10.1094/mpmi-20-4-0411] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Xylella fastidiosa is the causal agent of Pierce's disease of grape, an economically significant disease for the grape industry. X. fastidiosa systemically colonizes the xylem elements of grapevines and is able to breach the pit pore membranes separating xylem vessels by unknown mechanisms. We hypothesized that X. fastidiosa utilizes cell wall degrading enzymes to break down pit membranes, based on the presence of genes involved in plant cell wall degradation in the X. fastidiosa genome. These genes include several beta-1,4 endoglucanases, several xylanases, several xylosidases, and one polygalacturonase (PG). In this study, we demonstrated that the pglA gene encodes a functional PG. A mutant in pglA lost pathogenicity and was compromised in its ability to systemically colonize Vitis vinifera grapevines. The results indicate that PG is required for X. fastidiosa to successfully infect grapevines and is a critical virulence factor for X. fastidiosa pathogenesis in grapevine.
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Affiliation(s)
- M Caroline Roper
- Department of Plant Pathology, University of California, Davis. Davis, CA, 95616, USA
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134
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Feil H, Feil WS, Lindow SE. Contribution of Fimbrial and Afimbrial Adhesins of Xylella fastidiosa to Attachment to Surfaces and Virulence to Grape. PHYTOPATHOLOGY 2007; 97:318-324. [PMID: 18943651 DOI: 10.1094/phyto-97-3-0318] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
ABSTRACT The role of fimbrial and afimbrial adhesins of Xylella fastidiosa in biofilm formation was assessed by visualization of cell aggregates of mutant strains after incubation on glass surfaces. FimA- or FimF- fimbrial mutants adhered as solitary cells at a slightly lesser frequency to glass surfaces than the parental strain; however, cell aggregates were not formed, unlike the wild-type strain. Conversely, whereas the XadA- and HxfB- nonfimbrial mutants also exhibited a much lower frequency of adherence to glass surfaces than the wild-type strain, most of the cells retained on the surfaces were in cell aggregates of different sizes, much like that of the parental strain. Neither fimbrial or afimbrial mutants formed a mature biofilm on the sides of flasks of broth cultures, unlike the dense biofilm formed by the wild-type strain. Although FimA- and FimF- mutants did not form cell aggregates on glass surfaces when incubated as individual strains, aggregates of a FimA- or FimF- mutant were observed when co-incubated with either a XadA- mutant or HxfB- mutant, respectively. These results are consistent with a model in which the fimbrial adhesins FimA and FimF are involved preferentially in cell-to-cell aggregate formation whereas the afimbrial adhesions XadA and HxfB preferentially contribute to initial cell binding to surfaces, whereupon further cell aggregation can occur. In each of five separate experiments, FimA, FimF, XadA, and HxfB mutants of X. fastidiosa all were less virulent to grape than the corresponding wild-type strain. Fimbrial and afimbrial mutants might produce a reduced biofilm within vessels of grape and, hence, be deficient in various cell-density-dependent traits required for movement through the plant and, thus, virulence.
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135
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da Silva Neto JF, Koide T, Gomes SL, Marques MV. The single extracytoplasmic-function sigma factor of Xylella fastidiosa is involved in the heat shock response and presents an unusual regulatory mechanism. J Bacteriol 2006; 189:551-60. [PMID: 17098905 PMCID: PMC1797396 DOI: 10.1128/jb.00986-06] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Genome sequence analysis of the bacterium Xylella fastidiosa revealed the presence of two genes, named rpoE and rseA, predicted to encode an extracytoplasmic function (ECF) sigma factor and an anti-sigma factor, respectively. In this work, an rpoE null mutant was constructed in the citrus strain J1a12 and shown to be sensitive to exposure to heat shock and ethanol. To identify the X. fastidiosa sigma(E) regulon, global gene expression profiles were obtained by DNA microarray analysis of bacterial cells under heat shock, identifying 21 sigma(E)-dependent genes. These genes encode proteins belonging to different functional categories, such as enzymes involved in protein folding and degradation, signal transduction, and DNA restriction modification and hypothetical proteins. Several putative sigma(E)-dependent promoters were mapped by primer extension, and alignment of the mapped promoters revealed a consensus sequence similar to those of ECF sigma factor promoters of other bacteria. Like other ECF sigma factors, rpoE and rseA were shown to comprise an operon in X. fastidiosa, together with a third open reading frame (XF2241). However, upon heat shock, rpoE expression was not induced, while rseA and XF2241 were highly induced at a newly identified sigma(E)-dependent promoter internal to the operon. Therefore, unlike many other ECF sigma factors, rpoE is not autoregulated but instead positively regulates the gene encoding its putative anti-sigma factor.
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136
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Koide T, Vêncio RZN, Gomes SL. Global gene expression analysis of the heat shock response in the phytopathogen Xylella fastidiosa. J Bacteriol 2006; 188:5821-30. [PMID: 16885450 PMCID: PMC1540087 DOI: 10.1128/jb.00182-06] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Xylella fastidiosa is a phytopathogenic bacterium that is responsible for diseases in many economically important crops. Although different strains have been studied, little is known about X. fastidiosa stress responses. One of the better characterized stress responses in bacteria is the heat shock response, which induces the expression of specific genes to prevent protein misfolding and aggregation and to promote degradation of the irreversibly denatured polypeptides. To investigate X. fastidiosa genes involved in the heat shock response, we performed a whole-genome microarray analysis in a time course experiment. Globally, 261 genes were induced (9.7%) and 222 genes were repressed (8.3%). The expression profiles of the differentially expressed genes were grouped, and their expression patterns were validated by quantitative reverse transcription-PCR experiments. We determined the transcription start sites of six heat shock-inducible genes and analyzed their promoter regions, which allowed us to propose a putative consensus for sigma(32) promoters in Xylella and to suggest additional genes as putative members of this regulon. Besides the induction of classical heat shock protein genes, we observed the up-regulation of virulence-associated genes such as vapD and of genes for hemagglutinins, hemolysin, and xylan-degrading enzymes, which may indicate the importance of heat stress to bacterial pathogenesis. In addition, we observed the repression of genes related to fimbriae, aerobic respiration, and protein biosynthesis and the induction of genes related to the extracytoplasmic stress response and some phage-related genes, revealing the complex network of genes that work together in response to heat shock.
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Affiliation(s)
- Tie Koide
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000 São Paulo, Brazil
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Koutsoudis MD, Tsaltas D, Minogue TD, von Bodman SB. Quorum-sensing regulation governs bacterial adhesion, biofilm development, and host colonization in Pantoea stewartii subspecies stewartii. Proc Natl Acad Sci U S A 2006; 103:5983-8. [PMID: 16585516 PMCID: PMC1458684 DOI: 10.1073/pnas.0509860103] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2005] [Indexed: 01/17/2023] Open
Abstract
The phytopathogenic bacterium Pantoea stewartii subsp. stewartii synthesizes stewartan exo/capsular polysaccharide (EPS) in a cell density-dependent manner governed by the EsaI/EsaR quorum-sensing (QS) system. This study analyzes biofilm development and host colonization of the WT and QS regulatory mutant strains of P. stewartii. First, we show that the cell density-dependent synthesis of stewartan EPS, governed by the EsaI/EsaR QS system, is required for proper bacterial adhesion and development of spatially defined, 3D biofilms. Second, a nonvirulent mutant lacking the esaI gene adheres strongly to surfaces and develops densely packed, less structurally defined biofilms in vitro. This strain appears to be arrested in a low cell density developmental mode. Exposure of this strain to exogenous N-acyl-homoserine lactone counteracts this adhesion phenotype. Third, QS mutants lacking the EsaR repressor attach poorly to surfaces and form amorphous biofilms heavily enmeshed in excess EPS. Fourth, the WT strain disseminates efficiently within the xylem, primarily in a basipetal direction. In contrast, the two QS mutant strains remain largely localized at the site of infection. Fifth, and most significantly, epifluorescence microscopic imaging of infected leaf tissue and excised xylem vessels reveals that the bacteria colonize the xylem with unexpected specificity, particularly toward the annular rings and spiral secondary wall thickenings of protoxylem, as opposed to indiscriminate growth to fill the xylem lumen. These observations are significant to bacterial plant pathogenesis in general and may reveal targets for disease control.
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Affiliation(s)
| | | | - Timothy D. Minogue
- Plant Science, University of Connecticut, Storrs, CT 06269; and
- Pathogen Functional Genomic Resource Center, Center for Genomic Research, 9712 Medical Drive, Rockville, MD 20850
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