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Peng J, Wang X, Wang H, Li X, Zhang Q, Wang M, Yan J. Advances in understanding grapevine downy mildew: From pathogen infection to disease management. MOLECULAR PLANT PATHOLOGY 2024; 25:e13401. [PMID: 37991155 PMCID: PMC10788597 DOI: 10.1111/mpp.13401] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Accepted: 09/29/2023] [Indexed: 11/23/2023]
Abstract
Plasmopara viticola is geographically widespread in grapevine-growing regions. Grapevine downy mildew disease, caused by this biotrophic pathogen, leads to considerable yield losses in viticulture annually. Because of the great significance of grapevine production and wine quality, research on this disease has been widely performed since its emergence in the 19th century. Here, we review and discuss recent understanding of this pathogen from multiple aspects, including its infection cycle, disease symptoms, genome decoding, effector biology, and management and control strategies. We highlight the identification and characterization of effector proteins with their biological roles in host-pathogen interaction, with a focus on sustainable control methods against P. viticola, especially the use of biocontrol agents and environmentally friendly compounds.
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Affiliation(s)
- Junbo Peng
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Xuncheng Wang
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Hui Wang
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Xinghong Li
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Qi Zhang
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Meng Wang
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Jiye Yan
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
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Jhansirani N, Devappa V, Sangeetha CG, Sridhara S, Shankarappa KS, Mohanraj M. Identification of Potential Phytochemical/Antimicrobial Agents against Pseudoperonospora cubensis Causing Downy Mildew in Cucumber through In-Silico Docking. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12112202. [PMID: 37299181 DOI: 10.3390/plants12112202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/06/2023] [Accepted: 05/13/2023] [Indexed: 06/12/2023]
Abstract
Compatibility interactions between the host and the fungal proteins are necessary to successfully establish a disease in plants by fungi or other diseases. Photochemical and antimicrobial substances are generally known to increase plant resilience, which is essential for eradicating fungus infections. Through homology modeling and in silico docking analysis, we assessed 50 phytochemicals from cucumber (Cucumis sativus), 15 antimicrobial compounds from botanical sources, and six compounds from chemical sources against two proteins of Pseudoperonospora cubensis linked to cucumber downy mildew. Alpha and beta sheets made up the 3D structures of the two protein models. According to Ramachandran plot analysis, the QNE 4 effector protein model was considered high quality because it had 86.8% of its residues in the preferred region. The results of the molecular docking analysis showed that the QNE4 and cytochrome oxidase subunit 1 proteins of P. cubensis showed good binding affinities with glucosyl flavones, terpenoids and flavonoids from phytochemicals, antimicrobial compounds from botanicals (garlic and clove), and chemically synthesized compounds, indicating the potential for antifungal activity.
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Affiliation(s)
- Nagaraju Jhansirani
- Department of Plant Pathology, College of Horticulture-Bengaluru, University of Horticultural Sciences, Bagalkot 560 065, India
| | - Venkatappa Devappa
- Department of Plant Pathology, College of Horticulture-Bengaluru, University of Horticultural Sciences, Bagalkot 560 065, India
| | - Chittarada Gopal Sangeetha
- Department of Plant Pathology, College of Horticulture-Bengaluru, University of Horticultural Sciences, Bagalkot 560 065, India
| | - Shankarappa Sridhara
- Center for Climate Resilient Agriculture, Keladi Shivappa Nayaka University of Agricultural and Horticultural Sciences, Shivamogga 577 201, India
| | - Kodegandlu Subbanna Shankarappa
- Department of Plant Pathology, College of Horticulture-Bengaluru, University of Horticultural Sciences, Bagalkot 560 065, India
| | - Mooventhiran Mohanraj
- Department of Plant Pathology, College of Horticulture-Bengaluru, University of Horticultural Sciences, Bagalkot 560 065, India
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Secretome Profiling by Proteogenomic Analysis Shows Species-Specific, Temperature-Dependent, and Putative Virulence Proteins of Pythium insidiosum. J Fungi (Basel) 2022; 8:jof8050527. [PMID: 35628782 PMCID: PMC9144242 DOI: 10.3390/jof8050527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 05/15/2022] [Accepted: 05/16/2022] [Indexed: 02/04/2023] Open
Abstract
In contrast to most pathogenic oomycetes, which infect plants, Pythium insidiosum infects both humans and animals, causing a difficult-to-treat condition called pythiosis. Most patients undergo surgical removal of an affected organ, and advanced cases could be fetal. As a successful human/animal pathogen, P. insidiosum must tolerate body temperature and develop some strategies to survive and cause pathology within hosts. One of the general pathogen strategies is virulence factor secretion. Here, we used proteogenomic analysis to profile and validate the secretome of P. insidiosum, in which its genome contains 14,962 predicted proteins. Shotgun LC–MS/MS analysis of P. insidiosum proteins prepared from liquid cultures incubated at 25 and 37 °C mapped 2980 genome-predicted proteins, 9.4% of which had a predicted signal peptide. P. insidiosum might employ an alternative secretory pathway, as 90.6% of the validated secretory/extracellular proteins lacked the signal peptide. A comparison of 20 oomycete genomes showed 69 P. insidiosum–specific secretory/extracellular proteins, and these may be responsible for the host-specific infection. The differential expression analysis revealed 14 markedly upregulated proteins (particularly cyclophilin and elicitin) at body temperature which could contribute to pathogen fitness and thermotolerance. Our search through a microbial virulence database matched 518 secretory/extracellular proteins, such as urease and chaperones (including heat shock proteins), that might play roles in P. insidiosum virulence. In conclusion, the identification of the secretome promoted a better understanding of P. insidiosum biology and pathogenesis. Cyclophilin, elicitin, chaperone, and urease are top-listed secreted/extracellular proteins with putative pathogenicity properties. Such advances could lead to developing measures for the efficient detection and treatment of pythiosis.
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Fabro G. Oomycete intracellular effectors: specialised weapons targeting strategic plant processes. THE NEW PHYTOLOGIST 2022; 233:1074-1082. [PMID: 34705271 DOI: 10.1111/nph.17828] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/17/2021] [Indexed: 06/13/2023]
Abstract
Oomycete phytopathogens have adapted to colonise plants using effectors as their molecular weapons. Intracellular effectors, mostly proteins but also small ribonucleic acids, are delivered by the pathogens into the host cell cytoplasm where they interfere with normal plant physiology. The diverse host processes emerging as 'victims' of these 'specialised bullets' include gene transcription and RNA-mediated silencing, cell death, protein stability, protein secretion and autophagy. Some effector targets are directly involved in defence execution, while others participate in fundamental metabolisms whose alteration collaterally affects defences. Other effector targets are susceptibility factors (SFs), that is host components that make plants vulnerable to pathogens. SFs are mostly negative regulators of immunity, but some seem necessary to sustain or promote pathogen colonisation.
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Affiliation(s)
- Georgina Fabro
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET and Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina
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Andronis CE, Hane JK, Bringans S, Hardy GESJ, Jacques S, Lipscombe R, Tan KC. Gene Validation and Remodelling Using Proteogenomics of Phytophthora cinnamomi, the Causal Agent of Dieback. Front Microbiol 2021; 12:665396. [PMID: 34394023 PMCID: PMC8360494 DOI: 10.3389/fmicb.2021.665396] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 05/18/2021] [Indexed: 11/13/2022] Open
Abstract
Phytophthora cinnamomi is a pathogenic oomycete that causes plant dieback disease across a range of natural ecosystems and in many agriculturally important crops on a global scale. An annotated draft genome sequence is publicly available (JGI Mycocosm) and suggests 26,131 gene models. In this study, soluble mycelial, extracellular (secretome), and zoospore proteins of P. cinnamomi were exploited to refine the genome by correcting gene annotations and discovering novel genes. By implementing the diverse set of sub-proteomes into a generated proteogenomics pipeline, we were able to improve the P. cinnamomi genome annotation. Liquid chromatography mass spectrometry was used to obtain high confidence peptides with spectral matching to both the annotated genome and a generated 6-frame translation. Two thousand seven hundred sixty-four annotations from the draft genome were confirmed by spectral matching. Using a proteogenomic pipeline, mass spectra were used to edit the P. cinnamomi genome and allowed identification of 23 new gene models and 60 edited gene features using high confidence peptides obtained by mass spectrometry, suggesting a rate of incorrect annotations of 3% of the detectable proteome. The novel features were further validated by total peptide support, alongside functional analysis including the use of Gene Ontology and functional domain identification. We demonstrated the use of spectral data in combination with our proteogenomics pipeline can be used to improve the genome annotation of important plant diseases and identify missed genes. This study presents the first use of spectral data to edit and manually annotate an oomycete pathogen.
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Affiliation(s)
- Christina E Andronis
- Centre for Crop and Disease Management, Curtin University, Bentley, WA, Australia.,Proteomics International, Nedlands, WA, Australia
| | - James K Hane
- Centre for Crop and Disease Management, Curtin University, Bentley, WA, Australia.,Faculty of Science and Engineering, Curtin Institute for Computation, Curtin University, Perth, WA, Australia
| | | | - Giles E S J Hardy
- Centre for Phytophthora Science and Management, Murdoch University, Murdoch, WA, Australia
| | - Silke Jacques
- Centre for Crop and Disease Management, Curtin University, Bentley, WA, Australia
| | | | - Kar-Chun Tan
- Centre for Crop and Disease Management, Curtin University, Bentley, WA, Australia
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Chechi JL, Rotchanapreeda T, da Paz GS, Prado AC, Oliveira AL, Vieira JCS, Buzalaf MAR, Rodrigues AM, dos Santos LD, Krajaejun T, Bosco SDMG. Prospecting Biomarkers for Diagnostic and Therapeutic Approaches in Pythiosis. J Fungi (Basel) 2021; 7:jof7060423. [PMID: 34071174 PMCID: PMC8229905 DOI: 10.3390/jof7060423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 12/11/2022] Open
Abstract
Pythiosis, whose etiological agent is the oomycete Pythium insidiosum, is a life-threatening disease that occurs mainly in tropical and subtropical countries, affecting several animal species. It is frequently found in horses in Brazil and humans in Thailand. The disease is difficult to diagnose because the pathogen’s hyphae are often misdiagnosed as mucoromycete fungi in histological sections. Additionally, there is no specific antigen to use for rapid diagnosis, the availability of which could improve the prognosis in different animal species. In this scenario, we investigated which P. insidiosum antigens are recognized by circulating antibodies in horses and humans with pythiosis from Brazil and Thailand, respectively, using 2D immunoblotting followed by mass spectrometry for the identification of antigens. We identified 23 protein spots, 14 recognized by pooled serum from horses and humans. Seven antigens were commonly recognized by both species, such as the heat-shock cognate 70 KDa protein, the heat-shock 70 KDa protein, glucan 1,3-beta-glucosidase, fructose-bisphosphate aldolase, serine/threonine-protein phosphatase, aconitate hydratase, and 14-3-3 protein epsilon. These results demonstrate that there are common antigens recognized by the immune responses of horses and humans, and these antigens may be studied as biomarkers for improving diagnosis and treatment.
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Affiliation(s)
- Jéssica Luana Chechi
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (A.C.P.); (J.C.S.V.)
- Correspondence: (J.L.C.); (S.d.M.G.B.)
| | - Tiwa Rotchanapreeda
- Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; (T.R.); (T.K.)
| | - Giselle Souza da Paz
- Faculty of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu 18618-681, Brazil; (G.S.d.P.); (A.L.O.)
| | - Ana Carolina Prado
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (A.C.P.); (J.C.S.V.)
| | - Alana Lucena Oliveira
- Faculty of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu 18618-681, Brazil; (G.S.d.P.); (A.L.O.)
| | - José Cavalcante Souza Vieira
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (A.C.P.); (J.C.S.V.)
| | - Marília Afonso Rabelo Buzalaf
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo (USP), Bauru 17012-901, Brazil;
| | - Anderson Messias Rodrigues
- Department of Microbiology, Immunology and Parasitology, Cell Biology Division, Federal University of São Paulo (UNIFESP), São Paulo 04023-062, Brazil;
| | - Lucilene Delazari dos Santos
- Center for the Study of Venoms and Venomous Animals (CEVAP), São Paulo State University (UNESP), Botucatu 18610-307, Brazil;
- Graduate Program in Tropical Diseases, Botucatu Medical School (FMB), São Paulo State University (UNESP), Botucatu 18618-687, Brazil
| | - Theerapong Krajaejun
- Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; (T.R.); (T.K.)
| | - Sandra de Moraes Gimenes Bosco
- Department of Chemical and Biological Sciences, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (A.C.P.); (J.C.S.V.)
- Faculty of Veterinary Medicine and Animal Science (FMVZ), São Paulo State University (UNESP), Botucatu 18618-681, Brazil; (G.S.d.P.); (A.L.O.)
- Correspondence: (J.L.C.); (S.d.M.G.B.)
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Mar Htun Z, Laikul A, Pathomsakulwong W, Yurayart C, Lohnoo T, Yingyong W, Kumsang Y, Payattikul P, Sae-Chew P, Rujirawat T, Jittorntam P, Jaturapaktrarak C, Chongtrakool P, Krajaejun T. Identification and Biotyping of Pythium insidiosum Isolated from Urban and Rural Areas of Thailand by Multiplex PCR, DNA Barcode, and Proteomic Analyses. J Fungi (Basel) 2021; 7:242. [PMID: 33804838 PMCID: PMC8063814 DOI: 10.3390/jof7040242] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/13/2021] [Accepted: 03/15/2021] [Indexed: 12/20/2022] Open
Abstract
Pythium insidiosum causes pythiosis, a fatal infectious disease of humans and animals worldwide. Prompt diagnosis and treatment are essential to improve the clinical outcome of pythiosis. Diagnosis of P. insidiosum relies on immunological, molecular, and proteomic assays. The main treatment of pythiosis aims to surgically remove all affected tissue to prevent recurrent infection. Due to the marked increase in case reports, pythiosis has become a public health concern. Thailand is an endemic area of human pythiosis. To obtain a complete picture of how the pathogen circulates in the environment, we surveyed the presence of P. insidiosum in urban (Bangkok) and rural areas of Thailand. We employed the hair-baiting technique to screen for P. insidiosum in 500 water samples. Twenty-seven culture-positive samples were identified as P. insidiosum by multiplex PCR, multi-DNA barcode (rDNA, cox1, cox2), and mass spectrometric analyses. These environmental strains of P. insidiosum fell into Clade-II and -III genotypes and exhibited a close phylogenetic/proteomic relationship with Thai clinical strains. Biodiversity of the environmental strains also existed in a local habitat. In conclusion, P. insidiosum is widespread in Thailand. A better understanding of the ecological niche of P. insidiosum could lead to the effective prevention and control of this pathogen.
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Affiliation(s)
- Zin Mar Htun
- Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand;
- Department of Microbiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand;
- Department of Microbiology, University of Medicine, Mandalay 05024, Myanmar
| | - Aree Laikul
- Department of Large Animal and Wildlife Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Nakhon Pathom 73140, Thailand;
| | | | - Chompoonek Yurayart
- Department of Microbiology and Immunology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand;
| | - Tassanee Lohnoo
- Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; (T.L.); (W.Y.); (Y.K.); (P.P.); (P.S.-C.); (T.R.); (P.J.); (C.J.)
| | - Wanta Yingyong
- Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; (T.L.); (W.Y.); (Y.K.); (P.P.); (P.S.-C.); (T.R.); (P.J.); (C.J.)
| | - Yothin Kumsang
- Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; (T.L.); (W.Y.); (Y.K.); (P.P.); (P.S.-C.); (T.R.); (P.J.); (C.J.)
| | - Penpan Payattikul
- Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; (T.L.); (W.Y.); (Y.K.); (P.P.); (P.S.-C.); (T.R.); (P.J.); (C.J.)
| | - Pattarana Sae-Chew
- Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; (T.L.); (W.Y.); (Y.K.); (P.P.); (P.S.-C.); (T.R.); (P.J.); (C.J.)
| | - Thidarat Rujirawat
- Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; (T.L.); (W.Y.); (Y.K.); (P.P.); (P.S.-C.); (T.R.); (P.J.); (C.J.)
| | - Paisan Jittorntam
- Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; (T.L.); (W.Y.); (Y.K.); (P.P.); (P.S.-C.); (T.R.); (P.J.); (C.J.)
| | - Chalisa Jaturapaktrarak
- Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; (T.L.); (W.Y.); (Y.K.); (P.P.); (P.S.-C.); (T.R.); (P.J.); (C.J.)
| | - Piriyaporn Chongtrakool
- Department of Microbiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand;
| | - Theerapong Krajaejun
- Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand;
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Clinical Outcomes of Radical Surgery and Antimicrobial Agents in Vascular Pythiosis: A Multicenter Prospective Study. J Fungi (Basel) 2021; 7:jof7020114. [PMID: 33557064 PMCID: PMC7913857 DOI: 10.3390/jof7020114] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/01/2021] [Accepted: 02/01/2021] [Indexed: 01/21/2023] Open
Abstract
Vascular pythiosis is a rare, neglected, life-threatening disease with mortality of 100% in patients with incomplete surgical resection or patients with persistently elevated serum β-d-glucan (BDG). The study was conducted to understand the clinical outcomes of new treatment protocols and potential use of erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP) as alternative monitoring tools, given recent favorable minimum inhibitory concentrations (MICs) of antibacterial agents and prohibitive cost of serum BDG in Thailand. A prospective cohort study of patients with vascular pythiosis was conducted between February 2019 and August 2020. After diagnosis, patients were followed at 0.5, 1, 1.5, 3, and 6 months. Descriptive statistics, Spearman's correlation coefficient, and general linear model for longitudinal data were used. Amongst the cohort of ten vascular pythiosis patients, four had residual disease after surgery. Among four with residual disease, one developed disseminated disease and died, one developed relapse disease requiring surgery, and two were successfully managed with antimicrobial agents. The spearman's correlation coefficients between BDG and ESR, and between BDG and CRP in patients without relapse or disseminated disease were 0.65 and 0.60, respectively. Tetracyclines and macrolides had most favorable minimum inhibitory concentrations and synergistic effects were observed in combinations of these two antibiotic classes. Adjunctive use of azithromycin and doxycycline preliminarily improved survival in vascular pythiosis patients with residual disease. Further studies are needed to understand the trends of ESR and CRP in this population.
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Chitasombat MN, Jongkhajornpong P, Lekhanont K, Krajaejun T. Recent update in diagnosis and treatment of human pythiosis. PeerJ 2020; 8:e8555. [PMID: 32117626 PMCID: PMC7036273 DOI: 10.7717/peerj.8555] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/13/2020] [Indexed: 12/20/2022] Open
Abstract
Human pythiosis is an infectious condition with high morbidity and mortality. The causative agent is the oomycete microorganism Pythium insidiosum. The pathogen inhabits ubiquitously in a wet environment, and direct exposure to the pathogen initiates the infection. Most patients with pythiosis require surgical removal of the affected organ, and many patients die from the disease. Awareness of pythiosis among healthcare personnel is increasing. In this review, we summarized and updated information on the diagnosis and treatment of human pythiosis. Vascular and ocular pythiosis are common clinical manifestations. Recognition of the typical clinical features of pythiosis is essential for early diagnosis. The definitive diagnosis of the disease requires laboratory testing, such as microbiological, serological, molecular, and proteomic assays. In vascular pythiosis, surgical intervention to achieve the organism-free margin of the affected tissue, in combination with the use of antifungal drugs and P. insidiosum immunotherapy, remains the recommended treatment. Ocular pythiosis is a serious condition and earliest therapeutic penetrating keratoplasty with wide surgical margin is the mainstay treatment. Thorough clinical assessment is essential in all patients to evaluate the treatment response and detect an early sign of the disease recurrence. In conclusion, early diagnosis and proper management are the keys to an optimal outcome of the patients with pythiosis.
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Affiliation(s)
- Maria Nina Chitasombat
- Division of Infectious Disease, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Passara Jongkhajornpong
- Department of Ophthalmology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Kaevalin Lekhanont
- Department of Ophthalmology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Theerapong Krajaejun
- Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
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10
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Human Pythiosis: Emergence of Fungal-Like Organism. Mycopathologia 2019; 185:801-812. [PMID: 31845178 DOI: 10.1007/s11046-019-00412-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 11/28/2019] [Indexed: 01/10/2023]
Abstract
Pythiosis is an emerging infectious disease caused by the aquatic oomycete Pythium insidiosum, a fungal-like organism. It is believed that P. insidiosum's zoospores, its infected form, play major role in pathogenesis. Vascular and ocular infections are the most common clinical manifestation in humans. It is difficult to establish the diagnosis given its relatively rarity and difficulty to distinguish P. insidiosum from other molds. Delay in diagnosis and treatment has been associated with poor outcomes. High index of suspicion is the key, particularly in thalassemia patients with arterial insufficiency and patients with fungal keratitis/endophthalmitis without improvement on antifungal therapy. Tissue culture and zoospore induction remain gold standard for diagnosis; however, DNA-based method should be performed simultaneously. The combination of radical surgery, antifungal agents, and immunotherapy has been recommended. It was previously believed that surgery with negative surgical margins was the essential to survive in vascular pythiosis; however, it was recently found that patients could have residual disease despite documented negative surgical margins as infected clot may be dislodged to proximal arterial sites prior to surgery. Serum β-D-glucan (BG) has been used to monitor disease response after treatment initiation in vascular pythiosis. A significant decrease in BG levels within 2 weeks after surgery is indicative of the absence of residual infection. Unfortunately, monitoring tools for ocular pythiosis are not yet available. Itraconazole plus terbinafine have generally been used in P. insidiosum-infected patients; however, antibacterial agents, including azithromycin and linezolid, have also been used with favorable outcomes in ocular disease. Recently, azithromycin or clarithromycin plus doxycyclin were used in two relapsed vascular pythiosis patients with good outcomes.
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Chechi JL, Franckin T, Barbosa LN, Alves FCB, Leite ADL, Buzalaf MAR, Delazari Dos Santos L, Bosco SDMG. Inferring putative virulence factors for Pythium insidiosum by proteomic approach. Med Mycol 2019; 57:92-100. [PMID: 29373751 DOI: 10.1093/mmy/myx166] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 01/05/2018] [Indexed: 12/23/2022] Open
Abstract
Pythium insidiosum is the etiologic agent of pythiosis, a life-threatening disease that affects human and animals, has difficult diagnosis, and therapy. Studies on protein characterization of P. insidiosum are scarce, so we aimed to determine the protein profile of P. insidiosum by mass spectrometry and bioinformatics strategies targeting in proteins that may act as putative virulence factors. Therefore, an extraction protocol was standardized to obtain the total proteins of P. insidiosum. By the analysis of Image Master 2D Platinum software, it was found that 186 spots ranging between 12 and 89 KDa and isoelectric point from 4 to 7. By the analysis of 2D-SDS-PAGE it was possible to visualize and excise 103 spots, which were hydrolyzed with trypsin and submitted to mass spectrometry, resulting in the identification of 36 different proteins. Three of them were classified as proteins supposedly related to virulence factors due to its functions, such as glucan 1,3-beta glucosidase, Heat shock protein (Hsp) 70 and enolase. These results may contribute to a better understanding of the virulence factors of this medically important oomycete, as well as to subsidize new studies on diagnosis and therapeutic approaches.
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Affiliation(s)
- Jéssica Luana Chechi
- Department of Microbiology and Immunology, Univ. Estadual Paulista (UNESP), Botucatu, Sao Paulo, Brazil
| | - Tarsila Franckin
- Department of Microbiology and Immunology, Univ. Estadual Paulista (UNESP), Botucatu, Sao Paulo, Brazil
| | - Lidiane Nunes Barbosa
- Department of Microbiology and Immunology, Univ. Estadual Paulista (UNESP), Botucatu, Sao Paulo, Brazil.,Center for the Studies of Venoms and Venomous Animals (CEVAP), Univ Estadual Paulista (UNESP), Botucatu, Sao Paulo, Brazil
| | | | - Aline de Lima Leite
- Department of Biological Sciences, Bauru School of Dentistry, University of Sao Paulo (USP), Bauru, Brazil
| | | | - Lucilene Delazari Dos Santos
- Center for the Studies of Venoms and Venomous Animals (CEVAP), Univ Estadual Paulista (UNESP), Botucatu, Sao Paulo, Brazil.,Graduate Program in Tropical Diseases, Botucatu Medical School (FMB), Univ Estadual Paulista (UNESP), Botucatu, Sao Paulo, Brazil
| | - Sandra de Moraes Gimenes Bosco
- Department of Microbiology and Immunology, Univ. Estadual Paulista (UNESP), Botucatu, Sao Paulo, Brazil.,Center for the Studies of Venoms and Venomous Animals (CEVAP), Univ Estadual Paulista (UNESP), Botucatu, Sao Paulo, Brazil
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12
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Shen D, Tang Z, Wang C, Wang J, Dong Y, Chen Y, Wei Y, Cheng B, Zhang M, Grenville-Briggs LJ, Tyler BM, Dou D, Xia A. Infection mechanisms and putative effector repertoire of the mosquito pathogenic oomycete Pythium guiyangense uncovered by genomic analysis. PLoS Genet 2019; 15:e1008116. [PMID: 31017897 PMCID: PMC6502433 DOI: 10.1371/journal.pgen.1008116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 05/06/2019] [Accepted: 04/01/2019] [Indexed: 11/18/2022] Open
Abstract
Pythium guiyangense, an oomycete from a genus of mostly plant pathogens, is an effective biological control agent that has wide potential to manage diverse mosquitoes. However, its mosquito-killing mechanisms are almost unknown. In this study, we observed that P. guiyangense could utilize cuticle penetration and ingestion of mycelia into the digestive system to infect mosquito larvae. To explore pathogenic mechanisms, a high-quality genome sequence with 239 contigs and an N50 contig length of 1,009 kb was generated. The genome assembly is approximately 110 Mb, which is almost twice the size of other sequenced Pythium genomes. Further genome analysis suggests that P. guiyangense may arise from a hybridization of two related but distinct parental species. Phylogenetic analysis demonstrated that P. guiyangense likely evolved from common ancestors shared with plant pathogens. Comparative genome analysis coupled with transcriptome sequencing data suggested that P. guiyangense may employ multiple virulence mechanisms to infect mosquitoes, including secreted proteases and kazal-type protease inhibitors. It also shares intracellular Crinkler (CRN) effectors used by plant pathogenic oomycetes to facilitate the colonization of plant hosts. Our experimental evidence demonstrates that CRN effectors of P. guiyangense can be toxic to insect cells. The infection mechanisms and putative virulence effectors of P. guiyangense uncovered by this study provide the basis to develop improved mosquito control strategies. These data also provide useful knowledge on host adaptation and evolution of the entomopathogenic lifestyle within the oomycete lineage. A deeper understanding of the biology of P. guiyangense effectors might also be useful for management of other important agricultural pests. Utilization of biocontrol agents has emerged as a promising mosquito control strategy, and Pythium guiyangense has wide potential to manage diverse mosquitoes with high efficiency. However, the molecular mechanisms underlying pathological processes remain almost unknown. We observed that P. guiyangense invades mosquito larvae through cuticle penetration and through ingestion of mycelia via the digestive system, jointly accelerating mosquito larvae mortality. We also present a high-quality genome assembly of P. guiyangense that contains two distinct genome complements, which likely resulted from a hybridization of two parental species. Our analyses revealed expansions of kinases, proteases, kazal-type protease inhibitors, and elicitins that may be important for adaptation of P. guiyangense to a mosquito-pathogenic lifestyle. Moreover, our experimental evidence demonstrated that some Crinkler effectors of P. guiyangense can be toxic to insect cells. Our findings suggest new insights into oomycete evolution and host adaptation by animal pathogenic oomycetes. Our new genome resource will enable better understanding of infection mechanisms, with the potential to improve the biological control of mosquitoes and other agriculturally important pests.
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Affiliation(s)
- Danyu Shen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Zhaoyang Tang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Cong Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Jing Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Yumei Dong
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Yang Chen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Yun Wei
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Biao Cheng
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Meiqian Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | | | - Brett M. Tyler
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Daolong Dou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Ai Xia
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- * E-mail:
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13
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Liu Y, Lan X, Song S, Yin L, Dry IB, Qu J, Xiang J, Lu J. In Planta Functional Analysis and Subcellular Localization of the Oomycete Pathogen Plasmopara viticola Candidate RXLR Effector Repertoire. FRONTIERS IN PLANT SCIENCE 2018; 9:286. [PMID: 29706971 PMCID: PMC5908963 DOI: 10.3389/fpls.2018.00286] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 02/19/2018] [Indexed: 05/20/2023]
Abstract
Downy mildew is one of the most destructive diseases of grapevine, causing tremendous economic loss in the grape and wine industry. The disease agent Plasmopara viticola is an obligate biotrophic oomycete, from which over 100 candidate RXLR effectors have been identified. In this study, 83 candidate RXLR effector genes (PvRXLRs) were cloned from the P. viticola isolate "JL-7-2" genome. The results of the yeast signal sequence trap assay indicated that most of the candidate effectors are secretory proteins. The biological activities and subcellular localizations of all the 83 effectors were analyzed via a heterologous Agrobacterium-mediated Nicotiana benthamiana expression system. Results showed that 52 effectors could completely suppress cell death triggered by elicitin, 10 effectors could partially suppress cell death, 11 effectors were unable to suppress cell death, and 10 effectors themselves triggered cell death. Live-cell imaging showed that the majority of the effectors (76 of 83) could be observed with informative fluorescence signals in plant cells, among which 34 effectors were found to be targeted to both the nucleus and cytosol, 29 effectors were specifically localized in the nucleus, and 9 effectors were targeted to plant membrane system. Interestingly, three effectors PvRXLR61, 86 and 161 were targeted to chloroplasts, and one effector PvRXLR54 was dually targeted to chloroplasts and mitochondria. However, western blot analysis suggested that only PvRXLR86 carried a cleavable N-terminal transit peptide and underwent processing in planta. Many effectors have previously been predicted to target organelles, however, to the best of our knowledge, this is the first study to provide experimental evidence of oomycete effectors targeted to chloroplasts and mitochondria.
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Affiliation(s)
- Yunxiao Liu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Xia Lan
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Shiren Song
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Ling Yin
- Guangxi Crop Genetic Improvement and Biotechnology Laboratory, Guangxi Academy of Agricultural Sciences, Nanning, China
| | - Ian B. Dry
- CSIRO Agriculture & Food, Urrbrae, SA, Australia
| | - Junjie Qu
- Guangxi Crop Genetic Improvement and Biotechnology Laboratory, Guangxi Academy of Agricultural Sciences, Nanning, China
| | - Jiang Xiang
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Jiang Lu
- Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Guangxi Crop Genetic Improvement and Biotechnology Laboratory, Guangxi Academy of Agricultural Sciences, Nanning, China
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14
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Clinicopathological features and outcomes of pythiosis. Int J Infect Dis 2018; 71:33-41. [PMID: 29653202 DOI: 10.1016/j.ijid.2018.03.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 03/29/2018] [Accepted: 03/30/2018] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVES Vascular pythiosis is a life-threatening infection caused by the oomycete Pythium insidiosum. This article reports the clinical presentation, serodiagnosis, pathology, and outcomes seen at the authors' institution. METHODS The cases of patients with proven vascular pythiosis at Ramathibodi Hospital, Mahidol University, Bangkok, Thailand from January 2006 to December 2016 were analyzed retrospectively. RESULTS Thirteen patients were analyzed, eight of whom had underlying thalassemias. Of the remaining five patients, one had aplastic anemia, one had myelodysplasia, one had acute leukemia, one had cirrhosis, and one had alcoholism. Neutropenic patients showed a rapid clinical deterioration. Atypical presentations including carotid arteritis, aneurysm, brain abscess, and stroke occurred in the non-thalassemic patients. Serology yielded positive results in all cases, with a rapid turnaround time. Serology has the advantage of providing a presurgical diagnosis, which allows prompt surgery and clinical cure to be achieved. Pathology revealed a neutrophilic response in the acute phase and a later shift to granuloma. Immunotherapy in combination with itraconazole and terbinafine was given. The amputation rate was 77%, and disease-free surgical margins were achieved in five cases (38%). The mortality rate was 31%. CONCLUSIONS This study highlights new aspects of pythiosis, such as the unusual host, clinical presentation, serology as a marker for rapid diagnosis, histopathology, and outcomes. Early recognition of the disease with prompt multimodality treatment may improve survival.
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15
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A multi-omics study of the grapevine-downy mildew (Plasmopara viticola) pathosystem unveils a complex protein coding- and noncoding-based arms race during infection. Sci Rep 2018; 8:757. [PMID: 29335535 PMCID: PMC5768699 DOI: 10.1038/s41598-018-19158-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 12/15/2017] [Indexed: 12/16/2022] Open
Abstract
Fungicides are applied intensively to prevent downy mildew infections of grapevines (Vitis vinifera) with high impact on the environment. In order to develop alternative strategies we sequenced the genome of the oomycete pathogen Plasmopara viticola causing this disease. We show that it derives from a Phytophthora-like ancestor that switched to obligate biotrophy by losing genes involved in nitrogen metabolism and γ-Aminobutyric acid catabolism. By combining multiple omics approaches we characterized the pathosystem and identified a RxLR effector that trigger an immune response in the wild species V. riparia. This effector is an ideal marker to screen novel grape resistant varieties. Our study reveals an unprecedented bidirectional noncoding RNA-based mechanism that, in one direction might be fundamental for P. viticola to proficiently infect its host, and in the other might reduce the effects of the infection on the plant.
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16
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Evolution of the Sterol Biosynthetic Pathway of Pythium insidiosum and Related Oomycetes Contributes to Antifungal Drug Resistance. Antimicrob Agents Chemother 2017; 61:AAC.02352-16. [PMID: 28115356 DOI: 10.1128/aac.02352-16] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 01/19/2017] [Indexed: 11/20/2022] Open
Abstract
Pythiosis is a life-threatening infectious disease caused by the oomycete Pythium insidiosum Direct exposure to Py. insidiosum zoospores can initiate infections of the eye, limb, gastrointestinal tract, or skin/subcutaneous tissue. Treatments for pythiosis have mostly relied on surgery. Antifungal drugs are generally ineffective against Py. insidiosum However, one patient with an invasive Py. insidiosum infection recovered completely following treatment with terbinafine and itraconazole. Additionally, the drug target sterol biosynthetic enzymes have been identified in the oomycete Aphanomyces euteiches It remains an open question whether Py. insidiosum is susceptible to the antifungal drugs and harbors any of the known drug target enzymes. Here, we determined the in vitro susceptibilities of terbinafine and itraconazole against 30 isolates of Py. insidiosum We also analyzed endogenous sterols and searched for genes encoding the sterol biosynthetic enzymes in the genomes of Py. insidiosum and related oomycetes. The susceptibility assay showed that the growth of each of the Py. insidiosum isolates was inhibited by the antifungal agents, but only at difficult-to-achieve concentrations, which explains the clinical resistance of the drugs in the treatment of pythiosis patients. Genome searches of Py. insidiosum and related oomycetes demonstrated that these organisms contained an incomplete set of sterol biosynthetic enzymes. Gas chromatographic mass spectrometry did not detect any sterol end products in Py. insidiosum In conclusion, Py. insidiosum possesses an incomplete sterol biosynthetic pathway. Resistance to antifungal drugs targeting enzymes in the ergosterol biosynthetic pathway in Py. insidiosum was due to modifications or losses of some of the genes encoding the drug target enzymes.
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17
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Development of an Anti-Elicitin Antibody-Based Immunohistochemical Assay for Diagnosis of Pythiosis. J Clin Microbiol 2016; 54:43-8. [PMID: 26719582 DOI: 10.1128/jcm.02113-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pythiosis is an emerging and life-threatening infectious disease of humans and animals living in tropical and subtropical countries and is caused by the fungus-like organism Pythium insidiosum. Antifungals are ineffective against this pathogen. Most patients undergo surgical removal of the infected organ, and many die from advanced infections. Early and accurate diagnosis leads to prompt management and promotes better prognosis for affected patients. Immunohistochemical assays (IHCs) have been developed using rabbit antibodies raised against P. insidiosum crude extract, i.e., culture filtrate antigen (CFA), for the histodiagnosis of pythiosis, but cross-reactivity with pathogenic fungi compromises the diagnostic performance of the IHC. Therefore, there is a need to improve detection specificity. Recently, the elicitin protein, ELI025, was identified in P. insidiosum, but it was not identified in other human pathogens, including true fungi. The ELI025-encoding gene was successfully cloned and expressed as a recombinant protein in Escherichia coli. This study aims to develop a new IHC using the rabbit anti-ELI025 antibody (anti-ELI) and to compare its performance with the previously reported anti-CFA-based IHC. Thirty-eight P. insidiosum histological sections stained positive by anti-ELI-based and anti-CFA-based IHCs indicating 100% detection sensitivity for the two assays. The anti-ELI antibody stained negative for all 49 negative-control sections indicating 100% detection specificity. In contrast, the anti-CFA antibody stained positive for one of the 49 negative controls (a slide prepared from Fusarium-infected tissue) indicating 98% detection specificity. In conclusion, the anti-ELI based IHC is sensitive and specific for the histodiagnosis of pythiosis and is an improvement over the anti-CFA-based assay.
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18
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Anderson RG, Deb D, Fedkenheuer K, McDowell JM. Recent Progress in RXLR Effector Research. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 28:1063-72. [PMID: 26125490 DOI: 10.1094/mpmi-01-15-0022-cr] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Some of the most devastating oomycete pathogens deploy effector proteins, with the signature amino acid motif RXLR, that enter plant cells to promote virulence. Research on the function and evolution of RXLR effectors has been very active over the decade that has transpired since their discovery. Comparative genomics indicate that RXLR genes play a major role in virulence for Phytophthora and downy mildew species. Importantly, gene-for-gene resistance against these oomycete lineages is based on recognition of RXLR proteins. Comparative genomics have revealed several mechanisms through which this resistance can be broken, most notably involving epigenetic control of RXLR gene expression. Structural studies have revealed a core fold that is present in the majority of RXLR proteins, providing a foundation for detailed mechanistic understanding of virulence and avirulence functions. Finally, functional studies have demonstrated that suppression of host immunity is a major function for RXLR proteins. Host protein targets are being identified in a variety of plant cell compartments. Some targets comprise hubs that are also manipulated by bacteria and fungi, thereby revealing key points of vulnerability in the plant immune network.
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Affiliation(s)
- Ryan G Anderson
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, U.S.A
| | - Devdutta Deb
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, U.S.A
| | - Kevin Fedkenheuer
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, U.S.A
| | - John M McDowell
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, U.S.A
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Reanpang T, Orrapin S, Orrapin S, Arworn S, Kattipatanapong T, Srisuwan T, Vanittanakom N, Lekawanvijit SP, Rerkasem K. Vascular Pythiosis of the Lower Extremity in Northern Thailand. INT J LOW EXTR WOUND 2015; 14:245-50. [DOI: 10.1177/1534734615599652] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pythiosis is a disease caused by Pythium insidiosum, a fungus-like organism. P. insidiosum is pathogenic in mammals, particularly in horses, dogs, and humans. Human pythiosis can be classified into 4 types: (1) cutaneous/subcutaneous, (2) ocular, (3) vascular, and (4) disseminated pythiosis. Vascular pythiosis is a rare disease but a serious limb- and life-threatening infection. We reviewed 22 cases over a 10-year period in Maharaj Nakorn Chiang Mai/Chiang Mai University Hospital. The survival rate was around 63.6% during our follow-up period. The only effective treatment was complete excision of the infected tissue, which was done mainly by major amputation, such as above-knee amputation. This report raises awareness of this disease, which needs preemptive diagnosis and appropriate treatment.
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Affiliation(s)
- Termpong Reanpang
- Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Saritphat Orrapin
- Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Saranat Orrapin
- Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Supapong Arworn
- Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | | | - Tanop Srisuwan
- Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Nongnuch Vanittanakom
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Suree P. Lekawanvijit
- Department of Pathology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kittipan Rerkasem
- Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
- Research Institute of Health Science, Chiang Mai University, Thailand
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20
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Lerksuthirat T, Lohnoo T, Inkomlue R, Rujirawat T, Yingyong W, Khositnithikul R, Phaonakrop N, Roytrakul S, Sullivan TD, Krajaejun T. The elicitin-like glycoprotein, ELI025, is secreted by the pathogenic oomycete Pythium insidiosum and evades host antibody responses. PLoS One 2015; 10:e0118547. [PMID: 25793767 PMCID: PMC4368664 DOI: 10.1371/journal.pone.0118547] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/20/2015] [Indexed: 12/31/2022] Open
Abstract
Pythium insidiosum is a unique oomycete that can infect humans and animals. Patients with a P. insidiosum infection (pythiosis) have high rates of morbidity and mortality. The pathogen resists conventional antifungal drugs. Information on the biology and pathogenesis of P. insidiosum is limited. Many pathogens secrete proteins, known as effectors, which can affect the host response and promote the infection process. Elicitins are secretory proteins and are found only in the oomycetes, primarily in Phytophthora and Pythium species. In plant-pathogenic oomycetes, elicitins function as pathogen-associated molecular pattern molecules, sterol carriers, and plant defense stimulators. Recently, we reported a number of elicitin-encoding genes from the P. insidiosum transcriptome. The function of elicitins during human infections is unknown. One of the P. insidiosum elicitin-encoding genes, ELI025, is highly expressed and up-regulated at body temperature. This study aims to characterize the biochemical, immunological, and genetic properties of the elicitin protein, ELI025. A 12.4-kDa recombinant ELI025 protein (rELI025) was expressed in Escherichia coli. Rabbit anti-rELI025 antibodies reacted strongly with the native ELI025 in P. insidiosum’s culture medium. The detected ELI025 had two isoforms: glycosylated and non-glycosylated. ELI025 was not immunoreactive with sera from pythiosis patients. The region near the transcriptional start site of ELI025 contained conserved oomycete core promoter elements. In conclusion, ELI025 is a small, abundant, secreted glycoprotein that evades host antibody responses. ELI025 is a promising candidate for development of diagnostic and therapeutic targets for pythiosis.
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Affiliation(s)
- Tassanee Lerksuthirat
- Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
- Molecular Medicine Program, Multidisciplinary Unit, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Tassanee Lohnoo
- Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Ruchuros Inkomlue
- Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Thidarat Rujirawat
- Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
- Molecular Medicine Program, Multidisciplinary Unit, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Wanta Yingyong
- Research Center, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Rommanee Khositnithikul
- Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Narumon Phaonakrop
- Proteomics Research Laboratory, Genome Institute, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Sittiruk Roytrakul
- Proteomics Research Laboratory, Genome Institute, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Thomas D. Sullivan
- Department of Pediatrics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Theerapong Krajaejun
- Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
- * E-mail:
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21
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Zanette RA, Bitencourt PER, Kontoyiannis DP, Fighera RA, Flores MM, Kommers GD, Silva PS, Ludwig A, Moretto MB, Alves SH, Santurio JM. Complex interaction of deferasirox and Pythium insidiosum: iron-dependent attenuation of growth in vitro and immunotherapy-like enhancement of immune responses in vivo. PLoS One 2015; 10:e0118932. [PMID: 25738758 PMCID: PMC4349436 DOI: 10.1371/journal.pone.0118932] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 01/07/2015] [Indexed: 12/22/2022] Open
Abstract
Pythium insidiosum iron acquisition mechanisms are unknown. We previously showed that the iron chelator deferasirox had weak activity in vitro and in rabbits with experimental pythiosis. Here we show that deferasirox causes damage to P. insidiosum hyphae in vitro, but that activity is diminished in the presence of exogenous iron. The tissue activity of the proinflammatory enzyme adenosine deaminase and the histological pattern observed in pythiosis lesions of rabbits treated with deferasirox were similar to the ones in animals treated with immunotherapy.
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Affiliation(s)
- Régis A. Zanette
- Graduate Program in Pharmacology, Health Science Center, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil
| | - Paula E. R. Bitencourt
- Graduate Program in Pharmaceutical Sciences, Health Science Center, UFSM, Santa Maria, RS, Brazil
| | - Dimitrios P. Kontoyiannis
- Department of Infectious Diseases, Infection Control and Employee Health, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Rafael A. Fighera
- Graduate Program in Veterinary Medicine, Health Science Center, UFSM, Santa Maria, RS, Brazil
| | - Mariana M. Flores
- Graduate Program in Veterinary Medicine, Health Science Center, UFSM, Santa Maria, RS, Brazil
| | - Glaucia D. Kommers
- Graduate Program in Veterinary Medicine, Health Science Center, UFSM, Santa Maria, RS, Brazil
| | - Priscila S. Silva
- Graduate Program in Pharmaceutical Sciences, Health Science Center, UFSM, Santa Maria, RS, Brazil
| | - Aline Ludwig
- Graduate Program in Pharmacology, Health Science Center, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil
| | - Maria B. Moretto
- Graduate Program in Pharmaceutical Sciences, Health Science Center, UFSM, Santa Maria, RS, Brazil
| | - Sydney H. Alves
- Graduate Program in Pharmacology, Health Science Center, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil
- Graduate Program in Pharmaceutical Sciences, Health Science Center, UFSM, Santa Maria, RS, Brazil
| | - Janio M. Santurio
- Graduate Program in Pharmacology, Health Science Center, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil
- * E-mail:
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22
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Transcriptome analysis of the entomopathogenic oomycete Lagenidium giganteum reveals putative virulence factors. Appl Environ Microbiol 2014; 80:6427-36. [PMID: 25107973 DOI: 10.1128/aem.02060-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A combination of 454 pyrosequencing and Sanger sequencing was used to sample and characterize the transcriptome of the entomopathogenic oomycete Lagenidium giganteum. More than 50,000 high-throughput reads were annotated through homology searches. Several selected reads served as seeds for the amplification and sequencing of full-length transcripts. Phylogenetic analyses inferred from full-length cellulose synthase alignments revealed that L giganteum is nested within the peronosporalean galaxy and as such appears to have evolved from a phytopathogenic ancestor. In agreement with the phylogeny reconstructions, full-length L. giganteum oomycete effector orthologs, corresponding to the cellulose-binding elicitor lectin (CBEL), crinkler (CRN), and elicitin proteins, were characterized by domain organizations similar to those of pathogenicity factors of plant-pathogenic oomycetes. Importantly, the L. giganteum effectors provide a basis for detailing the roles of canonical CRN, CBEL, and elicitin proteins in the infectious process of an oomycete known principally as an animal pathogen. Finally, phylogenetic analyses and genome mining identified members of glycoside hydrolase family 5 subfamily 27 (GH5_27) as putative virulence factors active on the host insect cuticle, based in part on the fact that GH5_27 genes are shared by entomopathogenic oomycetes and fungi but are underrepresented in nonentomopathogenic genomes. The genomic resources gathered from the L. giganteum transcriptome analysis strongly suggest that filamentous entomopathogens (oomycetes and fungi) exhibit convergent evolution: they have evolved independently from plant-associated microbes, have retained genes indicative of plant associations, and may share similar cores of virulence factors, such as GH5_27 enzymes, that are absent from the genomes of their plant-pathogenic relatives.
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Pan JH, Kerkar SP, Siegenthaler MP, Hughes M, Pandalai PK. A complicated case of vascular Pythium insidiosum infection treated with limb-sparing surgery. Int J Surg Case Rep 2014; 5:677-80. [PMID: 25194603 PMCID: PMC4189057 DOI: 10.1016/j.ijscr.2014.05.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 05/02/2014] [Accepted: 05/29/2014] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION Pythiosis is a serious life- and limb-threatening infection endemic to Thailand, but rarely seen in the Western hemisphere. Here, we present a unique case of vascular pythiosis initially managed with limb-sparing vascular bypass grafts complicated by a pseudoaneurysm in our repair. PRESENTATION OF CASE The patient is a 17 year-old Jamaican male with severe aplastic anemia. He sustained a minor injury to his left leg while fishing in Jamaica, which evolved to become an exquisitely tender inguinal swelling. His physical exam and imaging were significant for arteriovenous fistula with limb ischemia. Pathology obtained during surgery for an extra-anatomic vascular bypass showed extensive invasion by Pythium insidiosum. He later developed a pseudoaneurysm at the site of proximal anastomosis and required urgent intervention. DISCUSSION This patient presented with a rare, but classic case of vascular pythiosis, which was unrecognized at the time of presentation. A variety of therapeutic modalities have been used to treat this disease, including antibiotics, antifungals, and immunotherapy, but the ultimate management of vascular pythiosis is surgical source control. CONCLUSION A high index of suspicion in susceptible patients is needed for timely diagnosis of vascular pythiosis to achieve optimal source control.
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Affiliation(s)
- Jenny H Pan
- Surgery Branch, National Cancer Institute, National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Sid P Kerkar
- Center for Cancer Research, National Cancer Institute, National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Michael P Siegenthaler
- National Institute of Health (NIH), Heart Center at Suburban Hospital, Bethesda, MD 20814, USA
| | - Marybeth Hughes
- Surgery Branch, National Cancer Institute, National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Prakash K Pandalai
- Surgery Branch, National Cancer Institute, National Institutes of Health (NIH), Bethesda, MD 20892, USA.
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Loreto &ES, Tondolo JSM, Zanette RA, Alves SH, Santurio JM. Update on pythiosis immunobiology and immunotherapy. World J Immunol 2014; 4:88-97. [DOI: 10.5411/wji.v4.i2.88] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 05/06/2014] [Accepted: 06/11/2014] [Indexed: 02/05/2023] Open
Abstract
Pythiosis is an invasive, ulcerative, pyogranulomatous disease caused by Pythium insidiosum, a fungus-like oomycete that has been reported to affect humans, horses, dogs, and other mammals mainly in tropical and subtropical areas of the world. The disease is characterized by an eosinophilic granulomatous and a Th2 immune response which in turn helps to protect the fungus from the host cells. Pythiosis can present clinically in subcutaneous, gastrointestinal, and vascular tissues or in a systemically disseminated form depending on the species and site of infection. Changes in iron metabolism and anemia are commonly observed. The diagnosis is accomplished through clinical and pathological features, laboratory characteristics of cultures, serological and molecular tests. Treatment includes radical surgery, antimicrobial drugs, immunotherapy or a combination of these treatments. Immunotherapy is a practical and non-invasive alternative for treating pythiosis which is believed to promote a switch from a Th2 to Th1 immune response, resulting in a favorable clinical response. This therapy has demonstrated cure rates above 70% and 55% in horses and humans but low cure rates in dogs and cats. Despite the curative properties of this type of immunotherapy, the antibodies that are produced do not prevent host reinfection. Thus, development of effective adjuvants and new diagnostic techniques for early disease diagnosis are of utmost importance. The aim of this review was to promote pythiosis awareness and to provide an update about the immunotherapy and immunobiology of this disease.
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Krajaejun T, Lerksuthirat T, Garg G, Lowhnoo T, Yingyong W, Khositnithikul R, Tangphatsornruang S, Suriyaphol P, Ranganathan S, Sullivan TD. Transcriptome analysis reveals pathogenicity and evolutionary history of the pathogenic oomycete Pythium insidiosum. Fungal Biol 2014; 118:640-53. [DOI: 10.1016/j.funbio.2014.01.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 12/03/2013] [Accepted: 01/24/2014] [Indexed: 12/14/2022]
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Zanette RA, Santurio JM, Loreto ÉS, Alves SH, Kontoyiannis DP. Toll-deficient Drosophila is susceptible to Pythium insidiosum infection. Microbiol Immunol 2013; 57:732-5. [PMID: 23865688 DOI: 10.1111/1348-0421.12082] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 07/10/2013] [Accepted: 07/12/2013] [Indexed: 02/03/2023]
Abstract
There is a paucity of animal models of pythiosis, a life-threatening disease of humans and animals, the immunopathogenesis of which is poorly understood. A pythiosis model was developed by injecting Toll (Tl)-deficient Drosophila melanogaster flies with Pythium insidiosum zoospores. The infected Tl mutant flies had significantly lower survival rates (73.7%) than did control flies. This study reveals the important role of Tl pathway activation in fly immune response to pythiosis.
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Affiliation(s)
- Régis A Zanette
- Graduate Program in Pharmacology, Federal University of Santa Maria, Avenida Roraima, 1000, Santa Maria, RS, 97105-900, Brazil; Department of Infectious Diseases, Infection Control and Employee Health, University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX, 77030, USA
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Jiang RHY, de Bruijn I, Haas BJ, Belmonte R, Löbach L, Christie J, van den Ackerveken G, Bottin A, Bulone V, Díaz-Moreno SM, Dumas B, Fan L, Gaulin E, Govers F, Grenville-Briggs LJ, Horner NR, Levin JZ, Mammella M, Meijer HJG, Morris P, Nusbaum C, Oome S, Phillips AJ, van Rooyen D, Rzeszutek E, Saraiva M, Secombes CJ, Seidl MF, Snel B, Stassen JHM, Sykes S, Tripathy S, van den Berg H, Vega-Arreguin JC, Wawra S, Young SK, Zeng Q, Dieguez-Uribeondo J, Russ C, Tyler BM, van West P. Distinctive expansion of potential virulence genes in the genome of the oomycete fish pathogen Saprolegnia parasitica. PLoS Genet 2013; 9:e1003272. [PMID: 23785293 PMCID: PMC3681718 DOI: 10.1371/journal.pgen.1003272] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 12/10/2012] [Indexed: 01/31/2023] Open
Abstract
Oomycetes in the class Saprolegniomycetidae of the Eukaryotic kingdom Stramenopila have evolved as severe pathogens of amphibians, crustaceans, fish and insects, resulting in major losses in aquaculture and damage to aquatic ecosystems. We have sequenced the 63 Mb genome of the fresh water fish pathogen, Saprolegnia parasitica. Approximately 1/3 of the assembled genome exhibits loss of heterozygosity, indicating an efficient mechanism for revealing new variation. Comparison of S. parasitica with plant pathogenic oomycetes suggests that during evolution the host cellular environment has driven distinct patterns of gene expansion and loss in the genomes of plant and animal pathogens. S. parasitica possesses one of the largest repertoires of proteases (270) among eukaryotes that are deployed in waves at different points during infection as determined from RNA-Seq data. In contrast, despite being capable of living saprotrophically, parasitism has led to loss of inorganic nitrogen and sulfur assimilation pathways, strikingly similar to losses in obligate plant pathogenic oomycetes and fungi. The large gene families that are hallmarks of plant pathogenic oomycetes such as Phytophthora appear to be lacking in S. parasitica, including those encoding RXLR effectors, Crinkler's, and Necrosis Inducing-Like Proteins (NLP). S. parasitica also has a very large kinome of 543 kinases, 10% of which is induced upon infection. Moreover, S. parasitica encodes several genes typical of animals or animal-pathogens and lacking from other oomycetes, including disintegrins and galactose-binding lectins, whose expression and evolutionary origins implicate horizontal gene transfer in the evolution of animal pathogenesis in S. parasitica. Fish are an increasingly important source of animal protein globally, with aquaculture production rising dramatically over the past decade. Saprolegnia is a fungal-like oomycete and one of the most destructive fish pathogens, causing millions of dollars in losses to the aquaculture industry annually. Saprolegnia has also been linked to a worldwide decline in wild fish and amphibian populations. Here we describe the genome sequence of the first animal pathogenic oomycete and compare the genome content with the available plant pathogenic oomycetes. We found that Saprolegnia lacks the large effector families that are hallmarks of plant pathogenic oomycetes, showing evolutionary adaptation to the host. Moreover, Saprolegnia harbors pathogenesis-related genes that were derived by lateral gene transfer from the host and other animal pathogens. The retrotransposon LINE family also appears to be acquired from animal lineages. By transcriptome analysis we show a high rate of allelic variation, which reveals rapidly evolving genes and potentially adaptive evolutionary mechanisms coupled to selective pressures exerted by the animal host. The genome and transcriptome data, as well as subsequent biochemical analyses, provided us with insight in the disease process of Saprolegnia at a molecular and cellular level, providing us with targets for sustainable control of Saprolegnia.
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Affiliation(s)
- Rays H Y Jiang
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
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Zanette RA, Alves SH, Pilotto MB, Weiblen C, Fighera RA, Wolkmer P, Flores MM, Santurio JM. Iron chelation therapy as a treatment for Pythium insidiosum in an animal model. J Antimicrob Chemother 2013; 68:1144-7. [DOI: 10.1093/jac/dks534] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
Pythium insidiosum causes life-threatening disease in mammals. Animals with pythiosis usually develop anemia, and most human patients are reported to have thalassemia and the major consequence of thalassemia, iron overload. Therefore, this study evaluated the iron metabolism in rabbits experimentally infected with P. insidiosum. Ten infected rabbits were divided into two groups: one groups received a placebo, and the other was treated with immunotherapy. Five rabbits were used as negative controls. The hematological and biochemical parameters, including the iron profile, were evaluated. Microcytic hypochromic anemia was observed in the infected animals, and this condition was more accentuated in the untreated group. The serum iron level was decreased, whereas the transferrin level was increased, resulting in low saturation. The level of stainable iron in hepatocytes was markedly decreased in the untreated group. A high correlation was observed between the total iron binding capacity and the lesion size, and this correlation likely confirms the affinity of P. insidiosum for iron. The data from this study corroborate the previous implications of iron in the pathogenesis of pythiosis in humans and animals.
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Abstract
Many destructive diseases of plants and animals are caused by oomycetes, a group of eukaryotic pathogens important to agricultural, ornamental, and natural ecosystems. Understanding the mechanisms underlying oomycete virulence and the genomic processes by which those mechanisms rapidly evolve is essential to developing effective long-term control measures for oomycete diseases. Several common mechanisms underlying oomycete virulence, including protein toxins and cell-entering effectors, have emerged from comparing oomycetes with different genome characteristics, parasitic lifestyles, and host ranges. Oomycete genomes display a strongly bipartite organization in which conserved housekeeping genes are concentrated in syntenic gene-rich blocks, whereas virulence genes are dispersed into highly dynamic, repeat-rich regions. There is also evidence that key virulence genes have been acquired by horizontal transfer from other eukaryotic and prokaryotic species.
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Affiliation(s)
- Rays H Y Jiang
- The Broad Institute of the Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142, USA.
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Loreto ES, Alves SH, Santurio JM, Nogueira CW, Zeni G. Diphenyl diselenide in vitro and in vivo activity against the oomycete Pythium insidiosum. Vet Microbiol 2011; 156:222-6. [PMID: 22055205 DOI: 10.1016/j.vetmic.2011.10.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 08/30/2011] [Accepted: 10/07/2011] [Indexed: 02/06/2023]
Abstract
This study evaluated the in vitro activity of diphenyl diselenide against 19 Pythium insidiosum isolates and the in vivo therapeutic response of rabbits with experimentally induced pythiosis. In vitro: susceptibility tests were performed using the broth macrodilution method in accordance with the CLSI document M38-A2. The criteria for interpretation were as follows: MIC-1 and MIC-2 (inhibition of 90% and 100% of mycelium growth, respectively) and the minimum fungicide concentration (MIC-3). In vivo: twenty rabbits were divided into four groups with five animals each and treated for 40 consecutive days: groups 1 and 2 (experimentally induced pythiosis) were treated with diphenyl diselenide (10mg/kg/day) and canola oil (1 mL/kg/day), respectively; groups 3 and 4 (controls) were treated with canola oil (1 mL/kg/day) and diphenyl diselenide (10mg/kg/day), respectively. Toxicity was evaluated using biochemical and haematological parameters. In vitro susceptibility tests showed that 89.4% of isolates had a MIC-1 ≤ 0.5 μg/mL, 84.2% of isolates had a MIC-2 ≤ 1.0 μg/mL and 94.7% of isolates had a MIC-3 ≤ 2.0 μg/mL. The in vivo assay suggested that this compound has a fungistatic activity, and the biochemical and haematological parameters indicated that there was no renal, hepatic or haematological toxicity. The comparison of the unsaturated iron binding capacity levels between animals with and without pythiosis suggested the involvement of iron metabolism in the pathogenesis of pythiosis. This study demonstrated the absence of detectable toxicity caused by diphenyl diselenide and the in vitro fungicidal and in vivo fungistatic activities of this drug, which makes it an option for future therapeutic approaches in the treatment of pythiosis.
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Affiliation(s)
- Erico Silva Loreto
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, RS, Brazil
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