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Wei J, Fei Z, Pan G, Weiss LM, Zhou Z. Current Therapy and Therapeutic Targets for Microsporidiosis. Front Microbiol 2022; 13:835390. [PMID: 35356517 PMCID: PMC8959712 DOI: 10.3389/fmicb.2022.835390] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/14/2022] [Indexed: 11/13/2022] Open
Abstract
Microsporidia are obligate intracellular, spore-forming parasitic fungi which are grouped with the Cryptomycota. They are both opportunistic pathogens in humans and emerging veterinary pathogens. In humans, they cause chronic diarrhea in immune-compromised patients and infection is associated with increased mortality. Besides their role in pébrine in sericulture, which was described in 1865, the prevalence and severity of microsporidiosis in beekeeping and aquaculture has increased markedly in recent decades. Therapy for these pathogens in medicine, veterinary, and agriculture has become a recent focus of attention. Currently, there are only a few commercially available antimicrosporidial drugs. New therapeutic agents are needed for these infections and this is an active area of investigation. In this article we provide a comprehensive summary of the current as well as several promising new agents for the treatment of microsporidiosis including: albendazole, fumagillin, nikkomycin, orlistat, synthetic polyamines, and quinolones. Therapeutic targets which could be utilized for the design of new drugs are also discussed including: tubulin, type 2 methionine aminopeptidase, polyamines, chitin synthases, topoisomerase IV, triosephosphate isomerase, and lipase. We also summarize reports on the utility of complementary and alternative medicine strategies including herbal extracts, propolis, and probiotics. This review should help facilitate drug development for combating microsporidiosis.
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Affiliation(s)
- Junhong Wei
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Zhihui Fei
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Guoqing Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Louis M. Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, United States
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Zeyang Zhou
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
- College of Life Sciences, Chongqing Normal University, Chongqing, China
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Buppajarntham A, Atikankul T, Putaporntip C, Jongwutiwes S, Suankratay C. Myositis Caused by Trachipleistophora hominis in a Person With Human Immunodeficiency Virus: The First Case in Thailand. Open Forum Infect Dis 2021; 8:ofab494. [PMID: 34877363 PMCID: PMC8643666 DOI: 10.1093/ofid/ofab494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 09/27/2021] [Indexed: 11/14/2022] Open
Abstract
Background To date, cases of extraintestinal micro-sporidiosis have been increasingly reported in both otherwise healthy and immunocompromised individuals. Among them, microsporidial myositis is very rare. To the best of our knowledge, this is the first report of microsporidial myositis caused by Trachipleistophora hominis in a patient with human immunodeficiency virus (HIV) in Thailand. Case report A Thai man with HIV presented with fever and muscle pain at both anterior thighs and left arm for 3 months. Muscle biopsy was performed, and pathology exhibited neutrophil infiltration and focal aggregations of microsporidial spores. The 18S ribosomal RNA sequence revealed the species of this microsporidium as T hominis, and albendazole of 800mg/day was initiated. He gradually improved, and was discharged home 6 weeks after hospitalization. Conclusions To the best of our knowledge, this is the first report of microsporidial myositis caused by Trachipleistophora hominis in a person with HIV in Thailand.
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Affiliation(s)
- Aubonphan Buppajarntham
- Division of Infectious Diseases, Department of Medicine, Bangkok Phuket Hospital, Phuket, Thailand
| | - Taywin Atikankul
- Department of Pathology, Queen Savang Vadhana Memorial Hospital, Thai Red Cross Society, Chonburi, Thailand
| | - Chaturong Putaporntip
- Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Somchai Jongwutiwes
- Molecular Biology of Malaria and Opportunistic Parasites Research Unit, Department of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Chusana Suankratay
- Division of Infectious Diseases, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
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Abstract
Microsporidia are obligate intracellular pathogens identified ∼150 years ago as the cause of pébrine, an economically important infection in silkworms. There are about 220 genera and 1,700 species of microsporidia, which are classified based on their ultrastructural features, developmental cycle, host-parasite relationship, and molecular analysis. Phylogenetic analysis suggests that microsporidia are related to the fungi, being grouped with the Cryptomycota as a basal branch or sister group to the fungi. Microsporidia can be transmitted by food and water and are likely zoonotic, as they parasitize a wide range of invertebrate and vertebrate hosts. Infection in humans occurs in both immunocompetent and immunodeficient hosts, e.g., in patients with organ transplantation, patients with advanced human immunodeficiency virus (HIV) infection, and patients receiving immune modulatory therapy such as anti-tumor necrosis factor alpha antibody. Clusters of infections due to latent infection in transplanted organs have also been demonstrated. Gastrointestinal infection is the most common manifestation; however, microsporidia can infect virtually any organ system, and infection has resulted in keratitis, myositis, cholecystitis, sinusitis, and encephalitis. Both albendazole and fumagillin have efficacy for the treatment of various species of microsporidia; however, albendazole has limited efficacy for the treatment of Enterocytozoon bieneusi. In addition, immune restoration can lead to resolution of infection. While the prevalence rate of microsporidiosis in patients with AIDS has fallen in the United States, due to the widespread use of combination antiretroviral therapy (cART), infection continues to occur throughout the world and is still seen in the United States in the setting of cART if a low CD4 count persists.
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Jiang H, Chen Y, Bao J, Li X, Feng C, Xing Y, Chen Q. Isolation of the Parasite Enterocytospora artemiae From Chinese Grass Shrimp ( Palaemonetes sinensis)-First Report in Asia. Front Cell Infect Microbiol 2020; 10:580088. [PMID: 33365276 PMCID: PMC7750389 DOI: 10.3389/fcimb.2020.580088] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 11/09/2020] [Indexed: 11/13/2022] Open
Abstract
Chinese grass shrimp (Palaemonetes sinensis) is an economically important crustacean in Chinese aquaculture. Recently, we found that shrimp in Panjin city were infected with microsporidia, a group of fungi. The hepatopancreas of several infected shrimp showed white turbidity and pathological changes that negatively affected the health and appearance of the shrimp. Histopathology and transmission electron microscopy were used to examine the development of the parasite within its parasitophorous vacuole. Our results indicated that microsporidia developed asynchronously within the same parasitophorous vacuole. The spores were predominantly small, and rod or oval-shaped. The sizes of fresh spores were approximately 3.1 × 2.4 μm and fixed spores were 1.9 × 1.1 μm. The polar filament was isofilar with 5-6 coils and the thickness was 103.2 nm. Merogonial divisions occurred by binary fission and sporogonial division occurred by plasmotomy. The small subunit ribosomal DNA sequence (1295 bp) from the parasite was highly similar to the previously reported parasite Enterocytospora artemiae (99% nucleotide identity, JX915760). Using maximum likelihood to analyze the phylogenetic relationships, we found that this microsporidian should be grouped within Clade IV, an Enterocytospora-like clade, of the Microsporidia phylum. Based on this parasite's life cycle characteristics, morphology, and small subunit ribosomal DNA sequence, the parasite described here is likely E. artemiae, which has previously only been described in Europe and North America. Thus, this is the first report of E. artemiae both in Asia and economically important shrimp.
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Affiliation(s)
- Hongbo Jiang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, Shenyang Agricultural University, Shenyang, China
| | - Yuwen Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, Shenyang Agricultural University, Shenyang, China
| | - Jie Bao
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, Shenyang Agricultural University, Shenyang, China
| | - Xiaodong Li
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, Shenyang Agricultural University, Shenyang, China
| | - Chengcheng Feng
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, Shenyang Agricultural University, Shenyang, China
| | - Yuenan Xing
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, Shenyang Agricultural University, Shenyang, China
| | - Qijun Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, Shenyang Agricultural University, Shenyang, China
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5
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Han B, Takvorian PM, Weiss LM. Invasion of Host Cells by Microsporidia. Front Microbiol 2020; 11:172. [PMID: 32132983 PMCID: PMC7040029 DOI: 10.3389/fmicb.2020.00172] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 01/24/2020] [Indexed: 12/15/2022] Open
Abstract
Microsporidia are found worldwide and both vertebrates and invertebrates can serve as hosts for these organisms. While microsporidiosis in humans can occur in both immune competent and immune compromised hosts, it has most often been seen in the immune suppressed population, e.g., patients with advanced HIV infection, patients who have had organ transplantation, those undergoing chemotherapy, or patients using other immune suppressive agents. Infection can be associated with either focal infection in a specific organ (e.g., keratoconjunctivitis, cerebritis, or hepatitis) or with disseminated disease. The most common presentation of microsporidiosis being gastrointestinal infection with chronic diarrhea and wasting syndrome. In the setting of advanced HIV infection or other cases of profound immune deficiency microsporidiosis can be extremely debilitating and carries a significant mortality risk. Microsporidia are transmitted as spores which invade host cells by a specialized invasion apparatus the polar tube (PT). This review summarizes recent studies that have provided information on the composition of the spore wall and PT, as well as insights into the mechanism of invasion and interaction of the PT and spore wall with host cells during infection.
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Affiliation(s)
- Bing Han
- Department of Pathology, Albert Einstein College of Medicine, New York, NY, United States
- Department of Pathogenic Biology, School of Basic Medical Sciences, Shandong University, Jinan, China
| | - Peter M. Takvorian
- Department of Pathology, Albert Einstein College of Medicine, New York, NY, United States
- Department of Biological Sciences, Rutgers University, Newark, NJ, United States
| | - Louis M. Weiss
- Department of Pathology, Albert Einstein College of Medicine, New York, NY, United States
- Department of Medicine, Albert Einstein College of Medicine, New York, NY, United States
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6
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Microsporidial myositis in adult-onset immunodeficiency: case-based review. Rheumatol Int 2019; 39:1995-2003. [PMID: 31501996 DOI: 10.1007/s00296-019-04439-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/31/2019] [Indexed: 10/26/2022]
Abstract
Polymyositis is a diagnosis of exclusion. In patients with odd features, it can be of infective etiology. A high index of suspicion is required for diagnosis. A 55-year-old gentleman presented with gradual-onset proximal muscle weakness. Examination revealed mild distal weakness but no rash. Muscle enzymes were raised and tests for autoantibodies were negative. Biopsy revealed microsporidiosis. In view of this unusual infection, immunodeficiency was considered and he was found to have lymphopenia which antedated his illness. Later, he developed cranial nerve palsies due to multiple lesions in the pons. In addition, he had Cytomegalovirus viremia. Literature was reviewed to identify 20 cases of microsporidial myositis, its presentation, underlying immunodeficient state, and clinical course. Infective polymyositis should be considered in a patient with paucity of clinical and serological autoimmune features. Lymphopenia can point to underlying immunodeficiency. CMV infection could be the contributor to or bystander-effect of idiopathic lymphopenia.
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7
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Abstract
INTRODUCTION Microsporidia have been increasingly reported to infect humans. The most common presentation of microsporidiosis is chronic diarrhea, a significant mortality risk in immune-compromised patients. Albendazole, which inhibits tubulin, and fumagillin, which inhibits methionine aminopeptidase type 2 (MetAP2), are the two main therapeutic agents used for treatment of microsporidiosis. In addition, to their role as emerging pathogens in humans, microsporidia are important pathogens in insects, aquaculture, and veterinary medicine. New therapeutic targets and therapies have become a recent focus of attention for medicine, veterinary, and agricultural use. Areas covered: Herein, we discuss the detection and symptoms of microsporidiosis in humans and the therapeutic targets that have been utilized for the design of new drugs for the treatment of this infection, including triosephosphate isomerase, tubulin, MetAP2, topoisomerase IV, chitin synthases, and polyamines. Expert opinion: Enterocytozoon bieneusi is the most common microsporidia in human infection. Fumagillin has a broader anti-microsporidian activity than albendazole and is active against both Ent. bieneusi and Encephaliozoonidae. Microsporidia lack methionine aminopeptidase type 1 and are, therefore, dependent on MetAP2, while mammalian cells have both enzymes. Thus, MetAP2 is an essential enzyme in microsporidia and new inhibitors of this pathway have significant promise as therapeutic agents.
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Affiliation(s)
- Bing Han
- Department of Pathology, Division of Tropical Medicine and Parasitology, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Louis M. Weiss
- Department of Pathology, Division of Tropical Medicine and Parasitology, Albert Einstein College of Medicine, Bronx, NY 10461
- Department of Medicine, Division of Infectious Diseases, Albert Einstein College of Medicine, Bronx, NY 10461
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8
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Stentiford GD, Becnel JJ, Weiss LM, Keeling PJ, Didier ES, Williams BAP, Bjornson S, Kent ML, Freeman MA, Brown MJF, Troemel ER, Roesel K, Sokolova Y, Snowden KF, Solter L. Microsporidia - Emergent Pathogens in the Global Food Chain. Trends Parasitol 2016; 32:336-348. [PMID: 26796229 PMCID: PMC4818719 DOI: 10.1016/j.pt.2015.12.004] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 11/26/2015] [Accepted: 12/07/2015] [Indexed: 02/07/2023]
Abstract
Intensification of food production has the potential to drive increased disease prevalence in food plants and animals. Microsporidia are diversely distributed, opportunistic, and density-dependent parasites infecting hosts from almost all known animal taxa. They are frequent in highly managed aquatic and terrestrial hosts, many of which are vulnerable to epizootics, and all of which are crucial for the stability of the animal-human food chain. Mass rearing and changes in global climate may exacerbate disease and more efficient transmission of parasites in stressed or immune-deficient hosts. Further, human microsporidiosis appears to be adventitious and primarily associated with an increasing community of immune-deficient individuals. Taken together, strong evidence exists for an increasing prevalence of microsporidiosis in animals and humans, and for sharing of pathogens across hosts and biomes.
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Affiliation(s)
- G D Stentiford
- Pathology and Molecular Systematics Team, Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth, Dorset DT4 8UB, UK
| | - -J J Becnel
- United States Department of Agriculture (USDA) Agricultural Research Center (ARS), Center for Medical, Agricultural, and Veterinary Entomology (CMAVE), 1600 South West 23rd Drive, Gainesville, FL, 32608, USA
| | - L M Weiss
- Albert Einstein College of Medicine, 1300 Morris Park Avenue, Forchheimer 504, Bronx, NY 10641, USA
| | - P J Keeling
- Canadian Institute for Advanced Research, Botany Department, University of British Columbia, 3529-6270 University Boulevard, Vancouver, BC, V6T 1Z4 Canada
| | - E S Didier
- Division of Microbiology, Tulane National Primate Research Center and Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University, 1440 Canal Street, New Orleans, LA 70112, USA
| | - B-A P Williams
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope, Stocker Road, Exeter EX4 4QD, UK
| | - S Bjornson
- Department of Biology, Saint Mary's University, 923 Robie Street, Halifax, Nova Scotia, Canada
| | - M-L Kent
- Departments of Microbiology and Biomedical Sciences, 220 Nash Hall, Oregon State University, Corvallis, OR 97331, USA
| | - M A Freeman
- Ross University School of Veterinary Medicine, St. Kitts, West Indies
| | - M J F Brown
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - E-R Troemel
- University of California, San Diego, 4202 Bonner Hall, 9500 Gilman Drive #0349, La Jolla, CA 92093-0349, USA
| | - K Roesel
- International Livestock Research Institute, c/o Freie Universität Berlin, Institute of Parasitology and Tropical Veterinary Medicine, Robert-von-Ostertag-Strasse 7-13, Berlin, 14163 Germany
| | - Y Sokolova
- Department of Comparative Biomedical Sciences, Louisiana State University, School of Veterinary Medicine, 1909 Skip Bertman Drive, Baton RougeLA 70803, USA
| | - K F Snowden
- Texas A&M University, College of Veterinary Medicine and Biomedical Sciences, Department of Veterinary Pathobiology, Mailstop 4467, College Station, TX 77843-4467, USA
| | - L Solter
- Illinois Natural History Survey, Prairie Research Institute at the University of Illinois at Urbana-Champaign, 1816 South Oak Street, Champaign, IL 61820, USA.
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Desjardins CA, Sanscrainte ND, Goldberg JM, Heiman D, Young S, Zeng Q, Madhani HD, Becnel JJ, Cuomo CA. Contrasting host-pathogen interactions and genome evolution in two generalist and specialist microsporidian pathogens of mosquitoes. Nat Commun 2015; 6:7121. [PMID: 25968466 PMCID: PMC4435813 DOI: 10.1038/ncomms8121] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 04/07/2015] [Indexed: 12/14/2022] Open
Abstract
Obligate intracellular pathogens depend on their host for growth yet must also evade detection by host defenses. Here we investigate host adaptation in two Microsporidia, the specialist Edhazardia aedis and the generalist Vavraia culicis, pathogens of disease vector mosquitoes. Genomic analysis and deep RNA-Seq across infection time courses reveal fundamental differences between these pathogens. E. aedis retains enhanced cell surface modification and signalling capacity, upregulating protein trafficking and secretion dynamically during infection. V. culicis is less dependent on its host for basic metabolites and retains a subset of spliceosomal components, with a transcriptome broadly focused on growth and replication. Transcriptional profiling of mosquito immune responses reveals that response to infection by E. aedis differs dramatically depending on the mode of infection, and that antimicrobial defensins may play a general role in mosquito defense against Microsporidia. This analysis illuminates fundamentally different evolutionary paths and host interplay of specialist and generalist pathogens.
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Affiliation(s)
| | - Neil D Sanscrainte
- USDA, ARS, Center for Medical, Agricultural and Veterinary Entomology, 1600 SW 23rd Drive, Gainesville, Florida 32608, USA
| | | | - David Heiman
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Sarah Young
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Qiandong Zeng
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Hiten D Madhani
- Department of Biochemistry and Biophysics, University of California-San Francisco, San Francisco, California 94158, USA
| | - James J Becnel
- USDA, ARS, Center for Medical, Agricultural and Veterinary Entomology, 1600 SW 23rd Drive, Gainesville, Florida 32608, USA
| | - Christina A Cuomo
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
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Patel AK, Patel KK, Chickabasaviah YT, Shah SD, Patel DJ, Narayanappa G, Kumar A. Microsporidial polymyositis in human immunodeficiency virus-infected patients, a rare life-threatening opportunistic infection: clinical suspicion, diagnosis, and management in resource-limited settings. Muscle Nerve 2015; 51:775-80. [PMID: 25388126 DOI: 10.1002/mus.24513] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2014] [Indexed: 11/07/2022]
Abstract
INTRODUCTION Microsporidial myositis is a rare opportunistic infection that has been reported in HIV-infected and HIV-uninfected immunocompromised patients. METHODS In this study we present a retrospective analysis of 5 cases of microsporidial myositis in HIV-infected patients, including the clinical, laboratory, and histologic features, and a review of the literature. RESULTS Five young men with HIV infection [median CD4 count of 20 cells (range 14-144)/mm(3) ] who presented with signs and symptoms suggestive of myositis underwent EMG-NCV and muscle biopsy, which revealed signs compatible with microsporidial myositis. Early and aggressive treatment led to improvement in 3 patients. Two of the 5 patients died due to a delay in diagnosis, because the spores were mistaken for Candida without confirmatory stains or a high index of suspicion. CONCLUSIONS Myositis in HIV-infected patients with low CD4 counts should be evaluated using muscle biopsy. A high index of suspicion is required for early diagnosis of microsporidial myositis in HIV-infected patients. Early diagnosis and immediate, aggressive treatment are the keys to favorable outcomes in these patients.
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Affiliation(s)
- Atul K Patel
- Infectious Diseases Clinic, Vedanta Institute of Medical Sciences, Navarangpura, Ahmedabad, 380009, India
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Watts MR, Chan RCF, Cheong EYL, Brammah S, Clezy KR, Tong C, Marriott D, Webb CE, Chacko B, Tobias V, Outhred AC, Field AS, Prowse MV, Bertouch JV, Stark D, Reddel SW. Anncaliia algerae microsporidial myositis. Emerg Infect Dis 2014; 20:185-91. [PMID: 24447398 PMCID: PMC3901472 DOI: 10.3201/eid2002.131126] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The insect microsporidian Anncaliia algerae was first described in 2004 as a cause of fatal myositis in an immunosuppressed person from Pennsylvania, USA. Two cases were subsequently reported, and we detail 2 additional cases, including the only nonfatal case. We reviewed all 5 case histories with respect to clinical characteristics, diagnosis, and management and summarized organism life cycle and epidemiology. Before infection, all case-patients were using immunosuppressive medications for rheumatoid arthritis or solid-organ transplantation. Four of the 5 case-patients were from Australia. All diagnoses were confirmed by skeletal muscle biopsy; however, peripheral nerves and other tissues may be infected. The surviving patient received albendazole and had a reduction of immunosuppressive medications and measures to prevent complications. Although insects are the natural hosts for A. algerae, human contact with water contaminated by spores may be a mode of transmission. A. algerae has emerged as a cause of myositis, particularly in coastal Australia.
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Abstract
Parasitism, aptly defined as one of the 'living-together' strategies (Trager, 1986), presents a dynamic system in which the parasite and its host are under evolutionary pressure to evolve new and specific adaptations, thus enabling the coexistence of the two closely interacting partners. Microsporidia are very frequently encountered obligatory intracellular protistan parasites that can infect both animals and some protists and are a consummate example of various aspects of the 'living-together' strategy. Microsporidia, relatives of fungi in the superkingdom Opisthokonta, belong to the relatively small group of parasites for which the host cell cytoplasm is the site of both reproduction and maturation. The structural and physiological reduction of their vegetative stage, together with the manipulation of host cell physiology, enables microsporidia to live in the cytosolic environment for most of their life cycle in a way resembling endocytobionts. The ability to form structurally complex spores and the invention and assembly of a unique injection mechanism enable microsporidia to disperse within host tissues and between host organisms, resulting in long-lasting infections. Microsporidia have adapted their genomes to the intracellular way of life, evolved strategies how to obtain nutrients directly from the host and how to manipulate not only the infected cells, but also the hosts themselves. The enormous variability of host organisms and their tissues provide microsporidian parasites a virtually limitless terrain for diversification and ecological expansion. This review attempts to present a general overview of microsporidia, emphasising some less known and/or more recently discovered facets of their biology.
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Ultrastructure, development, and molecular phylogeny of Pleistophora hyphessobryconis, a broad host microsporidian parasite of Puntius tetrazona. Parasitol Res 2012; 111:1715-24. [DOI: 10.1007/s00436-012-3013-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Accepted: 06/13/2012] [Indexed: 11/24/2022]
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14
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Ultrastructure and molecular phylogenetics of a new isolate of Pleistophora pagri sp. nov. (Microsporidia, Pleistophoridae) from Pagrus pagrus in Egypt. Parasitol Res 2012; 111:1587-97. [PMID: 22773009 DOI: 10.1007/s00436-012-3012-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 06/04/2012] [Indexed: 10/28/2022]
Abstract
The spore morphology and molecular systematic of a new microsporidian which was isolated from the common sea bream Pagrus pagrus (F: Sparidae Linnaeus, 1758) from the Red Sea, Egypt have been studied. Fifty-six out of 300 (18.7%) of this fish were infected with microsporidian parasites. The infection was appeared as whitish, ellipsoid, round, or elongated nodules embedded in the epithelial lining of the peritoneum and also in the intestinal epithelium. Light microscopic study revealed that nodules were encapsulated by a fibrous layer encircling numerous mature spores measuring 1.7 ± 0.6 (1.5-2.7 μm) × 1.5 ± 0.3 μm (1.2-1.8 μm) in size. Ultrastructure of spores was characteristic for the genus Pleistophora: dimorphic, uninucleate spores (each spore possesses three to five polar filament coils) and a posterior vacuole. Also, the early recognizable stages of the parasite within nodules include uninucleated, binucleated, and multinucleated meronts followed by detachment of the plasmalemma of the sporont producing sporoblasts which mature to spores that consist of a spore coat and spore contents. Also, we analyzed the small subunit ribosomal gene (SSUrDNA) using PCR and sequencing specimens from the marine populations of P. pagrus fish from the Red Sea. From blast searches, sequence analysis, and phylogenetic analysis, we did not find corresponding GenBank entries to our species. Comparison of the nucleotide sequences showed that the sequence of our microsporidium was most similar to five Pleistophora species with degrees of identity (>91.5%). It was most similar (97.8% identity) to that of Pleistophora hyphessobryconis (account no. GU126672) differing in 19 nucleotide positions and with lower divergence value, Pleistophora ovariae (96.2% identity, account no. AJ252955), Pleistophora hippoglossoideos (91.9% identity, account no. AJ252953), Pleistophora mulleri (91.9% identity, account no. EF119339), and Pleistophora typicalis (91.9% identity, account no. AJ252956). So, they likely represent new species named Pleistophora pagri sp. n. with accession number JF797622 and a GC content of 53%.
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Ghosh K, Weiss LM. T cell response and persistence of the microsporidia. FEMS Microbiol Rev 2011; 36:748-60. [PMID: 22126330 DOI: 10.1111/j.1574-6976.2011.00318.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 10/28/2011] [Accepted: 11/08/2011] [Indexed: 11/28/2022] Open
Abstract
The microsporidia are a diverse phylum of obligate intracellular parasites related to the fungi that cause significant and sometimes life-threatening disease in immune-compromised hosts, such as AIDS and organ transplant patients. More recently, their role in causing pathology in immune-competent populations has also been appreciated. Interestingly, in several instances, the microsporidia have been shown to persist in their hosts long term, causing at opposite ends of the spectrum either an intractable chronic diarrhea and wasting in patients with advanced-stage AIDS or asymptomatic shedding of spores in healthy populations. Much remains to be studied regarding the immune response to these pathogens, but it seems clear that CD8+ T cells are essential in clearing infection. However, in the infection models examined thus far, the role for CD4+ T cells is unclear at best. Here, we discuss the possible reasons and ramifications of what may be a weak primary CD4+ T cell response against Encephalitozoon cuniculi. Given the central role of the CD4+ T cell in other models of adaptive immunity, a better appreciation of its role in responding to microsporidia may provide insight into the survival strategies of these pathogens, which allow them to persist in hosts of varied immune status.
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Affiliation(s)
- Kaya Ghosh
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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16
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Cali A, Neafie R, Weiss LM, Ghosh K, Vergara RB, Gupta R, Takvorian PM. Human vocal cord infection with the Microsporidium Anncaliia algerae. J Eukaryot Microbiol 2010; 57:562-7. [PMID: 20958855 DOI: 10.1111/j.1550-7408.2010.00510.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We describe a biopsy proven case of microsporidial infection of the false vocal cords in a 69-yr-old male with a history of chronic lymphocytic leukemia. The patient had hoarseness for several weeks before his admission to the hospital for shortness of breath. He had received chemotherapy with fludarabine 6 wk before this hospital admission. A biopsy of vocal cord nodules demonstrated an organism that was identified as Anncaliia algerae by electron microscopy. Molecular analysis of the small subunit RNA gene amplified by polymerase chain reaction further confirmed the identification of this organism as A. algerae. This case illustrates the ability of this insect pathogen to cause disease in immune-compromised mammalian hosts.
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Affiliation(s)
- Ann Cali
- Department of Biological Sciences, Rutgers University, Newark, New Jersey 07102, USA.
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17
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Structure of a microsporidian methionine aminopeptidase type 2 complexed with fumagillin and TNP-470. Mol Biochem Parasitol 2009; 168:158-67. [PMID: 19660503 DOI: 10.1016/j.molbiopara.2009.07.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 07/21/2009] [Accepted: 07/26/2009] [Indexed: 01/14/2023]
Abstract
Microsporidia are protists that have been reported to cause infections in both vertebrates and invertebrates. They have emerged as human pathogens particularly in patients that are immunosuppressed and cases of gastrointestinal infection, encephalitis, keratitis, sinusitis, myositis and disseminated infection are well described in the literature. While benzimidazoles are active against many species of microsporidia, these drugs do not have significant activity against Enterocytozoon bieneusi. Fumagillin and its analogues have been demonstrated to have activity invitro and in animal models of microsporidiosis and human infections due to E. bieneusi. Fumagillin and its analogues inhibit methionine aminopeptidase type 2. Encephalitozoon cuniculi MetAP2 (EcMetAP2) was cloned and expressed as an active enzyme using a baculovirus system. The crystal structure of EcMetAP2 was determined with and without the bound inhibitors fumagillin and TNP-470. This structure classifies EcMetAP2 as a member of the MetAP2c family. The EcMetAP2 structure was used to generate a homology model of the E. bieneusi MetAP2. Comparison of microsporidian MetAP2 structures with human MetAP2 provides insights into the design of inhibitors that might exhibit specificity for microsporidian MetAP2.
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18
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Monaghan SR, Kent ML, Watral VG, Kaufman RJ, Lee LEJ, Bols NC. Animal cell cultures in microsporidial research: their general roles and their specific use for fish microsporidia. In Vitro Cell Dev Biol Anim 2009; 45:135-47. [PMID: 19184249 PMCID: PMC4760642 DOI: 10.1007/s11626-008-9172-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Accepted: 12/20/2008] [Indexed: 10/21/2022]
Abstract
The use of animal cell cultures as tools for studying the microsporidia of insects and mammals is briefly reviewed, along with an in depth review of the literature on using fish cell cultures to study the microsporidia of fish. Fish cell cultures have been used less often but have had some success. Very short-term primary cultures have been used to show how microsporidia spores can modulate the activities of phagocytes. The most successful microsporidia/fish cell culture system has been relatively long-term primary cultures of salmonid leukocytes for culturing Nucleospora salmonis. Surprisingly, this system can also support the development of Enterocytozoon bienusi, which is of mammalian origin. Some modest success has been achieved in growing Pseudoloma neurophilia on several different fish cell lines. The eel cell line, EP-1, appears to be the only published example of any fish cell line being permanently infected with microsporidia, in this case Heterosporis anguillarum. These cell culture approaches promise to be valuable in understanding and treating microsporidia infections in fish, which are increasingly of economic importance.
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Affiliation(s)
- S Richelle Monaghan
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada.
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19
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IRONSIDE JOSEPHE, WILKINSON TOBYJ, ROCK JENNIFER. Distribution and Host Range of the MicrosporidianPleistophora mulleri. J Eukaryot Microbiol 2008; 55:355-62. [DOI: 10.1111/j.1550-7408.2008.00338.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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20
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Vávra J, Horák A, Modrý D, Lukes J, Koudela B. Trachipleistophora extenrec n. sp. a new microsporidian (fungi: microsporidia) infecting mammals. J Eukaryot Microbiol 2008; 53:464-76. [PMID: 17123410 DOI: 10.1111/j.1550-7408.2006.00139.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new microsporidian Trachipleistophora extenrec n. sp. was isolated from a muscle lesion of the streaked tenrec Hemicentetes semispinosus Cuvier, 1798 (Mammalia, Tenrecidae), an insectivore endemic to Madagascar. The spores isolated from the tenrec were infectious to severe combined immunodeficient (SCID) mice by intramuscular injection. Material obtained from muscular lesions in mice was used for the parasite description. All developmental stages of the microsporidian were covered by a dense coat, which during sporogony changed into the sporophorous vesicle wall. Eight, 16, 32, or more spores were formed inside the sporophorous vesicle as the result of the division by plasmotomy and sequential fission of a multinucleate sporogonial plasmodium. Spores were ovoid, 4.7 x 2.8 microm in size, had a large posterior vacuole, and had an isofilar polar tube with 15-16 coils. Although the fine structure and the developmental pattern of the organism were in some respects similar to the genus Vavraia, molecular phylogeny based on the gene sequences of the small subunit rRNA and RNA polymerase subunit II indicated that the organism belongs to the genus Trachipleistophora. The diagnostic characters of the genera Trachipleistophora and Vavraia are discussed as well as the discrepancies between the phylogenies of these two microsporidian genera based on morphology and molecules.
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Affiliation(s)
- Jirí Vávra
- Institute of Parasitology, Biological Centre of the Czech Academy of Sciences, Ceské Budejovice, Czech Republic
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21
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Wang W, Chen J. Ultrastructural study on a novel microsporidian, Endoreticulatus eriocheir sp. nov. (Microsporidia, Encephalitozoonidae), parasite of Chinese mitten crab, Eriocheir sinensis (Crustacea, Decapoda). J Invertebr Pathol 2007; 94:77-83. [PMID: 17097104 DOI: 10.1016/j.jip.2006.09.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2005] [Revised: 09/14/2006] [Accepted: 09/25/2006] [Indexed: 10/23/2022]
Abstract
A microsporidian pathogen, infecting the epithelial cells of the hepatopancreas of Chinese mitten crab, Eriocheir sinensis, was studied by electron microscopy. The detailed ultrastructure of life cycle of the pathogen including proliferative and sporogonic developmental stages are provided. All stages of the parasite are haplokaryotic and develop in a vacuole bounded by a single membrane in contact with host cell cytoplasm. Sporogenesis is synchronous with the same developmental stage in one vacuole. Sporogony shows a characteristic of multinucleate sporogonial plasmodia divided by rosette-like division, producing 4 or 8 sporoblasts. The mature spore is ellipsoidal, length (mean) 1.7 microm, width 1.0 microm, with a uninucleate in the center of the sporoplasm, 7 turns of the polar filament, a bell-like polaroplast of compact membranes and obliquely positioned posterior vacuole. The morphological characteristics of this novel microsporidian pathogen have led us to assign the parasite to a new species of Endoreticulatus, E. eriocheir sp. nov., that has not been reported previously from crab.
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Affiliation(s)
- Wen Wang
- Department of Biological Science and Technology, Nanjing University, Nanjing 210093, P.R. China.
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22
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Didier ES, Maddry JA, Brindley PJ, Stovall ME, Didier PJ. Therapeutic strategies for human microsporidia infections. Expert Rev Anti Infect Ther 2007; 3:419-34. [PMID: 15954858 DOI: 10.1586/14787210.3.3.419] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Over the past 20 years, microsporidia have emerged as a cause of infectious diseases in AIDS patients, organ transplant recipients, children, travelers, contact lens wearers and the elderly. Enterocytozoon bieneusi and the Encephalitozoon spp., Encephalitozoon cuniculi, Encephalitozoon hellem and Encephalitozoon intestinalis, are the most frequently identified microsporidia in humans, and are associated with diarrhea and systemic disease. The microsporidia are small, single-celled, obligately intracellular parasites that have been identified in water sources, as well as in wild, domestic and food-producing farm animals, thereby raising concerns for waterborne, foodborne and zoonotic transmission. Current therapies for microsporidiosis include albendazole, a benzimidazole that inhibits microtubule assembly and is effective against several microsporidia, including the Encephalitozoon spp., although it is less effective against Encephalitozoon bieneusi. Fumagillin, an antibiotic and antiangiogenic compound produced by Aspergillus fumigatus, is more broadly effective against Encephalitozoon spp. and E. bieneusi; however, is toxic when administered systemically to mammals. Recent studies are also focusing on compounds that target the microsporidia polyamines (e.g., polyamine analogs), methionine aminopeptidase 2 (e.g., fumagillin-related compounds), chitin inhibitors (e.g., nikkomycins), topoisomerases (e.g., fluoroquinolones) and tubulin (e.g., benzimidazole-related compounds).
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Affiliation(s)
- Elizabeth S Didier
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University, 1430 Tulane Avenue, New Orleans, LA 70112, USA.
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23
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24
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Zhang H, Huang H, Cali A, Takvorian PM, Feng X, Zhou G, Weiss LM. Investigations into microsporidian methionine aminopeptidase type 2: a therapeutic target for microsporidiosis. Folia Parasitol (Praha) 2005; 52:182-92. [PMID: 16004378 PMCID: PMC3109671 DOI: 10.14411/fp.2005.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The Microsporidia have been reported to cause a wide range of clinical diseases particularly in patients that are immunosuppressed. They can infect virtually any organ system and cases of gastrointestinal infection, encephalitis, ocular infection, sinusitis, myositis and disseminated infection are well described in the literature. While benzimidazoles such as albendazole are active against many species of Microsporidia, these drugs do not have significant activity against Enterocytozoon bieneusi. Fumagillin, ovalicin and their analogues have been demonstrated to have antimicrosporidial activity in vitro and in animal models of microsporidiosis. Fumagillin has also been demonstrated to have efficacy in human infections due to E. bieneusi. Fumagillin is an irreversible inhibitor of methionine aminopeptidase type 2 (MetAP2). Homology cloning employing the polymerase chain reaction was used to identify the MetAP2 gene from the human pathogenic microsporidia Encephalitozoon cuniculi, Encephalitozoon hellem, Encephalitozoon intestinalis, Brachiola algerae and E. bieneusi. The full-length MetAP2 coding sequence was obtained for all of the Encephalitozoonidae. Recombinant E. cuniculi MetAP2 was produced in baculovirus and purified using chromatographic techniques. The in vitro activity and effect of the inhibitors bestatin and TNP-470 on this recombinant microsporidian MetAP2 was characterized. An in silico model of E. cuniculi MetAP2 was developed based on crystallographic data on human MetAP2. These reagents provide new tools for the development of in vitro assay systems to screen candidate compounds for use as new therapeutic agents for the treatment of microsporidiosis.
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Affiliation(s)
- Hong Zhang
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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25
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Cali A, Weiss LM, Takvorian PM. A review of the development of two types of human skeletal muscle infections from microsporidia associated with pathology in invertebrates and cold-blooded vertebrates. Folia Parasitol (Praha) 2005; 52:51-61. [PMID: 16004364 PMCID: PMC3109649 DOI: 10.14411/fp.2005.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Traditionally, the Microsporidia were primarily studied in insects and fish. There were only a few human cases of microsporidiosis reported until the advent of AIDS, when the number of human microsporidian infections dramatically increased and the importance of these new pathogens to medicine became evident. Over a dozen different kinds of microsporidia infecting humans have been reported. While some of these infections were identified in new genera (Enterocytozoon, Vittaforma), there were also infections identified from established genera such as Pleistophora and Encephalitozoon. The genus Pleistophora, originally erected for a species described from fish muscle, and the genus Encephalitozoon, originally described from disseminated infection in rabbits, suggested a link between human infections and animals. In the 1980's, three Pleistophora sp. infections were described from human skeletal muscle without life cycles presented. Subsequently, the genus Trachipleistophora was established for a human-infecting microsporidium with developmental differences from species of the genus Pleistophora. Thus, the existence of a true Pleistophora sp. or spp. in humans was put into question. We have demonstrated the life-cycle stages of the original Pleistophora sp. infection from human muscle, confirming the existence of a true Pleistophora species in humans, P. ronneafiei Cali et Takvorian, 2003, the first demonstrated in a mammalian host. Another human infection, caused by a parasite from invertebrates, was Brachiola algerae Lowman, Takvorian et Cali, 2000. The developmental stages of this human muscle-infecting microsporidium demonstrate morphologically what we have also confirmed by molecular means, that B. algerae, the mosquito parasite, is the causative agent of this human skeletal muscle infection. B. algerae had previously been demonstrated in humans but only in surface infections, skin and eye. The diagnostic features of B. algerae and P. ronneafiei infections in human skeletal muscle are presented. While Encephalitozoon cuniculi has been known as both an animal (mammal) and human parasite, the idea of human microsporidial infections derived from cold-blooded vertebrates and invertebrates has only been suggested by microsporidian phylogeny based on small subunit ribosomal DNA sequences but has not been appreciated. The morphological data presented here demonstrate these relationships. Additionally, water, as a link that connects microsporidial spores in the environment to potential host organisms, is diagrammatically presented.
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Affiliation(s)
- Ann Cali
- Department of Biologic Sciences, Rutgers University, Newark, New Jersey 07102, USA.
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26
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Xu Y, Weiss LM. The microsporidian polar tube: a highly specialised invasion organelle. Int J Parasitol 2005; 35:941-53. [PMID: 16005007 PMCID: PMC3109658 DOI: 10.1016/j.ijpara.2005.04.003] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2005] [Revised: 03/28/2005] [Accepted: 04/05/2005] [Indexed: 11/30/2022]
Abstract
All of the members of the Microsporidia possess a unique, highly specialised structure, the polar tube. This article reviews the available data on the organisation, structure and function of this invasion organelle. It was over 100 years ago that Thelohan accurately described the microsporidian polar tube and the triggering of its discharge. In the spore, the polar tube is connected at the anterior end, and then coils around the sporoplasm. Upon appropriate environmental stimulation the polar tube rapidly discharges out of the spore pierces a cell membrane and serves as a conduit for sporoplasm passage into the new host cell. The mechanism of germination of spores, however, remains to be definitively determined. In addition, further studies on the characterisation of the early events in the rupture of the anterior attachment complex, eversion of the polar tube as well as the mechanism of host cell attachment and penetration are needed in order to clarify the function and assembly of this structure. The application of immunological and molecular techniques has resulted in the identification of three polar tube proteins referred to as PTP1, PTP2 and PTP3. The interactions of these identified proteins in the formation and function of the polar tube remain to be determined. Data suggest that PTP1 is an O-mannosylated glycoprotein, a post-translational modification that may be important for its function. With the availability of the Encephalitozoon cuniculi genome it is now possible to apply proteomic techniques to the characterisation of the components of the microsporidian spore and invasion organelle.
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Affiliation(s)
- Yanji Xu
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Louis M. Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Medicine, Albert Einstein College of Medicine, Room 504 Forchheimer Building, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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27
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Abstract
Microsporidia are long-known parasitic organisms of almost every animal group, including invertebrates and vertebrates. Microsporidia emerged as important opportunistic pathogens in humans when AIDS became pandemic and, more recently, have also increasingly been detected in otherwise immunocompromised patients, including organ transplant recipients, and in immunocompetent persons with corneal infection or diarrhea. Two species causing rare infections in humans, Encephalitozoon cuniculi and Brachiola vesicularum, had previously been described from animal hosts (vertebrates and insects, respectively). However, several new microsporidial species, including Enterocytozoon bieneusi, the most prevalent human microsporidian causing human immunodeficiency virus-associated diarrhea, have been discovered in humans, raising the question of their natural origin. Vertebrate hosts are now identified for all four major microsporidial species infecting humans (E. bieneusi and the three Encephalitozoon spp.), implying a zoonotic nature of these parasites. Molecular studies have identified phenotypic and/or genetic variability within these species, indicating that they are not uniform, and have allowed the question of their zoonotic potential to be addressed. The focus of this review is the zoonotic potential of the various microsporidia and a brief update on other microsporidia which have no known host or an invertebrate host and which cause rare infections in humans.
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Affiliation(s)
- Alexander Mathis
- Institute of Parasitology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
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28
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Abstract
Microsporidia have emerged as causes of infectious diseases in AIDS patients, organ transplant recipients, children, travelers, contact lens wearers, and the elderly. These organisms are small single-celled, obligate intracellular parasites that were considered to be early eukaryotic protozoa but were recently reclassified with the fungi. Of the 14 species of microsporidia currently known to infect humans, Enterocytozoon bieneusi and Encephalitozoon intestinalis are the most common causes of human infections and are associated with diarrhea and systemic disease. Species of microsporidia infecting humans have been identified in water sources as well as in wild, domestic, and food-producing farm animals, raising concerns for waterborne, foodborne, and zoonotic transmission. Current therapies for microsporidiosis include albendazole which is a benzimidazole that inhibits microtubule assembly and is effective against several microsporidia, including the Encephalitozoon species, but is less effective against E. bieneusi. Fumagillin, an antibiotic and anti-angiogenic compound produced by Aspergillus fumigatus, is more broadly effective against Encephalitozoon spp. and Enterocytozoon bieneusi but is toxic when administered systemically to mammals. Gene target studies have focused on methionine aminopeptidase 2 (MetAP2) for characterizing the mechanism of action and for identifying more effective, less toxic fumagillin-related drugs. Polyamine analogues have shown promise in demonstrating anti-microsporidial activity in culture and in animal models, and a gene encoding topoisomerase IV was identified in Vittaforma corneae, raising prospects for studies on fluoroquinolone efficacy against microsporidia.
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Affiliation(s)
- Elizabeth S Didier
- Division of Microbiology, Tulane National Primate Research Center, Covington, LA 70433, USA.
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Curry A, Beeching NJ, Gilbert JD, Scott G, Rowland PL, Currie BJ. Trachipleistophora hominis infection in the myocardium and skeletal muscle of a patient with AIDS. J Infect 2004; 51:e139-44. [PMID: 16230193 DOI: 10.1016/j.jinf.2004.11.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2004] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To review the literature relevant to microsporidial infection of muscle and to describe a case of human microsporidial infection involving both skeletal and cardiac muscle. METHODS Samples from an AIDS patient with myositis have been examined by light and electron microscopy. RESULTS We describe the findings at autopsy of a 47 year old Australian male with late stage AIDS, who had skeletal and cardiac muscle involvement with the microsporidian Trachipleistophora hominis. This is the third definitively identified case of human T. hominis infection and the first to describe infection of the myocardium. CONCLUSIONS Microsporidial infection of muscle is rare in humans, but more work is needed to elucidate both the organisms and routes of transmission of this group of parasitic protozoa.
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Affiliation(s)
- A Curry
- Health Protection Agency, Manchester Royal Infirmary, Clinical Sciences Building, Oxford Road, Manchester M13 9WL, UK.
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30
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Coyle CM, Weiss LM, Rhodes LV, Cali A, Takvorian PM, Brown DF, Visvesvara GS, Xiao L, Naktin J, Young E, Gareca M, Colasante G, Wittner M. Fatal myositis due to the microsporidian Brachiola algerae, a mosquito pathogen. N Engl J Med 2004; 351:42-7. [PMID: 15229306 PMCID: PMC3109631 DOI: 10.1056/nejmoa032655] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Christina M Coyle
- Department of Medicine, Jacobi Medical Center, Bronx, NY 10461, USA.
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