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de Albuquerque NRM, Haag KL. Using average nucleotide identity (ANI) to evaluate microsporidia species boundaries based on their genetic relatedness. J Eukaryot Microbiol 2023; 70:e12944. [PMID: 36039868 DOI: 10.1111/jeu.12944] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/26/2022] [Accepted: 08/27/2022] [Indexed: 11/28/2022]
Abstract
Microsporidia are obligatory intracellular parasites related to fungi and since their discovery their classification and origin has been controversial due to their unique morphology. Early taxonomic studies of microsporidia were based on ultrastructural spore features, characteristics of their life cycle and transmission modes. However, taxonomy and phylogeny based solely on these characteristics can be misleading. SSU rRNA is a traditional marker used in taxonomical classifications, but the power of SSU rRNA to resolve phylogenetic relationships between microsporidia is considered weak at the species level, as it may not show enough variation to distinguish closely related species. Overall genome relatedness indices (OGRI), such as average nucleotide identity (ANI), allows fast and easy-to-implement comparative measurements between genomes to assess species boundaries in prokaryotes, with a 95% cutoff value for grouping genomes of the same species. Due to the increasing availability of complete genomes, metrics of genome relatedness have been applied for eukaryotic microbes taxonomy such as microsporidia. However, the distribution of ANI values and cutoff values for species delimitation have not yet been fully tested in microsporidia. In this study we examined the distribution of ANI values for 65 publicly available microsporidian genomes and tested whether the 95% cutoff value is a good estimation for circumscribing species based on their genetic relatedness.
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Affiliation(s)
- Nathalia R M de Albuquerque
- Department of Genetics and Post-Graduation Program of Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Karen L Haag
- Department of Genetics and Post-Graduation Program of Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
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2
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Jaroenlak P, Cammer M, Davydov A, Sall J, Usmani M, Liang FX, Ekiert DC, Bhabha G. 3-Dimensional organization and dynamics of the microsporidian polar tube invasion machinery. PLoS Pathog 2020; 16:e1008738. [PMID: 32946515 PMCID: PMC7526891 DOI: 10.1371/journal.ppat.1008738] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/30/2020] [Accepted: 06/23/2020] [Indexed: 02/04/2023] Open
Abstract
Microsporidia, a divergent group of single-celled eukaryotic parasites, harness a specialized harpoon-like invasion apparatus called the polar tube (PT) to gain entry into host cells. The PT is tightly coiled within the transmissible extracellular spore, and is about 20 times the length of the spore. Once triggered, the PT is rapidly ejected and is thought to penetrate the host cell, acting as a conduit for the transfer of infectious cargo into the host. The organization of this specialized infection apparatus in the spore, how it is deployed, and how the nucleus and other large cargo are transported through the narrow PT are not well understood. Here we use serial block-face scanning electron microscopy to reveal the 3-dimensional architecture of the PT and its relative spatial orientation to other organelles within the spore. Using high-speed optical microscopy, we also capture and quantify the entire PT germination process of three human-infecting microsporidian species in vitro: Anncaliia algerae, Encephalitozoon hellem and E. intestinalis. Our results show that the emerging PT experiences very high accelerating forces to reach velocities exceeding 300 μm⋅s-1, and that firing kinetics differ markedly between species. Live-cell imaging reveals that the nucleus, which is at least 7 times larger than the diameter of the PT, undergoes extreme deformation to fit through the narrow tube, and moves at speeds comparable to PT extension. Our study sheds new light on the 3-dimensional organization, dynamics, and mechanism of PT extrusion, and shows how infectious cargo moves through the tube to initiate infection.
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Affiliation(s)
- Pattana Jaroenlak
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, New York, New York, United States of America
| | - Michael Cammer
- Microscopy Laboratory, Division of Advanced Research Technologies, New York University School of Medicine, New York, New York, United States of America
| | - Alina Davydov
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, New York, New York, United States of America
| | - Joseph Sall
- Microscopy Laboratory, Division of Advanced Research Technologies, New York University School of Medicine, New York, New York, United States of America
| | - Mahrukh Usmani
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, New York, New York, United States of America
| | - Feng-Xia Liang
- Microscopy Laboratory, Division of Advanced Research Technologies, New York University School of Medicine, New York, New York, United States of America
| | - Damian C. Ekiert
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, New York, New York, United States of America
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Gira Bhabha
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, New York, New York, United States of America
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3
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Sokolova YY, Weidner E, DiMario PJ. Development of Anncaliia algerae (Microsporidia) in Drosophila melanogaster. J Eukaryot Microbiol 2019; 67:125-131. [PMID: 31529563 DOI: 10.1111/jeu.12762] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/24/2019] [Accepted: 08/30/2019] [Indexed: 12/22/2022]
Abstract
Representatives of the genus Anncaliia are known as natural parasites of dipteran and coleopteran insects, amphipod crustaceans, but also humans, primarily with immunodeficiency. Anncaliia algerae-caused fatal myositis is considered as an emergent infectious disease in humans. A. (=Nosema, Brachiola) algerae, the best studied species of the genus, demonstrates the broadest among microsporidia range of natural and experimental hosts, but it has never been propagated in Drosophila. We present ultrastructural analysis of development of A. algerae in visceral muscles and adipocytes of Drosophila melanogaster 2 wk after per oral experimental infection. We observed typical to Anncaliia spp. features of ultrastructure and cell pathology including spore morphology, characteristic extensions of the plasma membrane, and presence of "ridges" and appendages of tubular material at proliferative stages. Anncaliia algerae development in D. melanogaster was particularly similar to one of A. algerae and A.(Brachiola) vesicularum in humans with acute myositis. Given D. melanogaster is currently the most established genetic model, with a fully sequenced genome and easily available transgenic forms and genomic markers, a novel host-parasite system might provide new genetic tools to investigate host-pathogen interactions of A. algerae, as well to test antimicrosporidia drugs.
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Affiliation(s)
- Yuliya Y Sokolova
- Institute of Cytology, 4 Tikhoretsky Av\194064, St. Petersburg, Russia.,Louisiana State University, Life Sciences Bldg, Baton Rouge, Louisiana, 70803, USA.,The George Washington University, Washington, District of Columbia, 20037, USA
| | - Earl Weidner
- Louisiana State University, Life Sciences Bldg, Baton Rouge, Louisiana, 70803, USA
| | - Patrick J DiMario
- Louisiana State University, Life Sciences Bldg, Baton Rouge, Louisiana, 70803, USA
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4
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Tokarev YS, Sokolova YY, Vasilieva AA, Issi IV. Molecular and Morphological Characterization of Anncaliia azovica
sp. n. (Microsporidia) Infecting Niphargogammarus intermedius
(Crustacea, Amphipoda) from the Azov Sea. J Eukaryot Microbiol 2017; 65:296-307. [DOI: 10.1111/jeu.12473] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/06/2017] [Accepted: 09/08/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Yuri S. Tokarev
- All-Russia Institute for Plant Protection; Russian Academy of Sciences; 3 Shosse Podbelskogo Pushkin-St. Petersburg 189620 Russia
| | - Yuliya Y. Sokolova
- Institute of Cytology; Russian Academy of Sciences; 4 Tikhoretsky Avenue St. Petersburg 194064 Russia
- Microscopy Center, Department of Comparative Biological Sciences; School of Veterinary Medicine, Louisiana State University; 1909 Skip Bertman Drive Baton Rouge Louisiana 70803
| | - Aleksandra A. Vasilieva
- All-Russia Institute for Plant Protection; Russian Academy of Sciences; 3 Shosse Podbelskogo Pushkin-St. Petersburg 189620 Russia
- Peter the Great St. Petersburg Polytechnic University; 29 Politechnicheskaya ul. St. Petersburg 195251 Russia
| | - Irma V. Issi
- All-Russia Institute for Plant Protection; Russian Academy of Sciences; 3 Shosse Podbelskogo Pushkin-St. Petersburg 189620 Russia
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5
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Santiana M, Takvorian PM, Altan-Bonnet N, Cali A. A Novel Fluorescent Labeling Method Enables Monitoring of Spatio-Temporal Dynamics of Developing Microsporidia. J Eukaryot Microbiol 2015; 63:318-25. [PMID: 26567000 DOI: 10.1111/jeu.12281] [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] [Received: 09/29/2015] [Revised: 10/28/2015] [Accepted: 11/02/2015] [Indexed: 12/01/2022]
Abstract
The microsporidium, Anncaliia algerae (Brachiola algerae), is a eukaryotic obligate intracellular parasite first isolated from mosquitoes and is an important opportunistic human pathogen that can cause morbidity and mortality among immune-compromised individuals including patients with AIDS and those undergoing chemotherapy. There is little known about the Microsporidia-host cell interface in living host cells, due to current approaches being limited by the lack of fluorescent reporters for detecting the parasite lifecycle. Here, we have developed and applied novel vital fluorescent parasite labeling methodologies in conjunction with fluorescent protein-tagged reporters to track simultaneously the dynamics of both parasite and host cell specific components, including the secretory and endocytic trafficking pathways, during the entire infection time period. We have found dramatic changes in the dynamics of host secretory trafficking organelles during the course of infection. The Golgi compartment is gradually disassembled and regenerated into mini-Golgi structures in parallel with cellular microtubule depolymerization. Importantly, we find that Microsporidia progeny are associated with these de novo formed mini-Golgi structures. These host structures appear to create a membrane bound niche environment for parasite development. Our studies presented here provide novel imaging tools and methodologies that will facilitate in understanding the biology of microsporidial parasites in the living host.
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Affiliation(s)
- Marianita Santiana
- Federated Department of Biological Sciences, Rutgers University, Newark, New Jersey, 07102.,Laboratory of Host-Pathogen Dynamics, Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Peter M Takvorian
- Federated Department of Biological Sciences, Rutgers University, Newark, New Jersey, 07102
| | - Nihal Altan-Bonnet
- Laboratory of Host-Pathogen Dynamics, Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Ann Cali
- Federated Department of Biological Sciences, Rutgers University, Newark, New Jersey, 07102
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6
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Santiana M, Pau C, Takvorian PM, Cali A. Analysis of the beta-tubulin gene and morphological changes of the microsporidium Anncaliia algerae both suggest albendazole sensitivity. J Eukaryot Microbiol 2014; 62:60-8. [PMID: 25105446 DOI: 10.1111/jeu.12160] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 05/27/2014] [Accepted: 07/08/2014] [Indexed: 11/29/2022]
Abstract
The Microsporidium, Anncaliia algerae, an obligate intracellular parasite, has been identified as an opportunistic human pathogen, but treatment has not been evaluated for infections with this organism. Albendazole, an antitubulin polymerization drug used against parasitic worm infections, has been the medication of choice used to treat some microsporidial infections affecting humans, with varying results ranging from clearing infection (Encephalitozoon) to resistance (Enterocytozoon). This study illustrates the effect of albendazole treatment on A. algerae infection in Rabbit Kidney (RK13) cells and Human Fetal Lung (HFL-1) fibroblasts. Albendazole appears to have an attenuating effect on A. algerae infection and albendazole's IC50 in RK13 cells is 0.1 μg/ml. Long-term treatment inhibits up to 98% of spore production, but interrupting treatment reestablishes the infection without new exposure to the parasite as supported by microscopic observations. The parasite's beta-tubulin gene was purified, cloned, and sequenced. Five of the six specific amino acids, associated with benzimidazole sensitivity, are conserved in A. algerae. These findings suggest that A. algerae is sensitive to albendazole; however, the organism is not completely cleared from cultures.
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7
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Galván-Díaz AL, Magnet A, Fenoy S, Henriques-Gil N, Haro M, Gordo FP, Miró G, del Águila C, Izquierdo F. Microsporidia detection and genotyping study of human pathogenic E. bieneusi in animals from Spain. PLoS One 2014; 9:e92289. [PMID: 24651457 PMCID: PMC3961313 DOI: 10.1371/journal.pone.0092289] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 02/20/2014] [Indexed: 12/03/2022] Open
Abstract
Microsporidia are ubiquitous parasites infecting all animal phyla and we present evidence that supports their zoonotic potential. Fecal samples taken from domestic (cats and dogs), farm (pigs, rabbits and ostriches) and wild animals (foxes) from different provinces of Spain were evaluated for microsporidia infection by light microscopy and PCR. After Microsporidia species identification, E. bieneusi genotypes were additionally studied by sequence analysis of the ITS region. Eighty-five samples out of 159 exhibited structures that were compatible with microsporidia spores by Webeŕs stain with 37 of them being confirmed by PCR. Microsporidia species identified included E. bieneusi, E. intestinalis and A. algerae. We report the first diagnosis of E. intestinalis and E. bieneusi in ostriches and A. algerae in pigs. We also provide new information on the molecular characterization of E. bieneusi isolates both in rabbits and ostriches. All of the E. bieneusi genotypes identified belonged to the zoonotic group of genotypes (Group I) including genotypes A (dogs), I (pigs), D (rabbits and foxes) and type IV (ostriches). Our results demonstrate that microsporidia are present in domestic, farm and wild animals in Spain, corroborating their potential role as a source of human infection and environmental contamination.
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Affiliation(s)
- Ana Luz Galván-Díaz
- Facultad de Farmacia, Universidad San Pablo CEU, Boadilla del Monte, Madrid, Spain
- Escuela de Microbiología, Grupo de Parasitología, Universidad de Antioquia, Medellín, Colombia
| | - Angela Magnet
- Facultad de Farmacia, Universidad San Pablo CEU, Boadilla del Monte, Madrid, Spain
| | - Soledad Fenoy
- Facultad de Farmacia, Universidad San Pablo CEU, Boadilla del Monte, Madrid, Spain
| | - Nuno Henriques-Gil
- Facultad de Medicina, Universidad San Pablo CEU, Boadilla del Monte, Madrid, Spain
| | - María Haro
- Facultad de Farmacia, Universidad San Pablo CEU, Boadilla del Monte, Madrid, Spain
| | | | - Guadalupe Miró
- Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Madrid, Spain
| | - Carmen del Águila
- Facultad de Farmacia, Universidad San Pablo CEU, Boadilla del Monte, Madrid, Spain
| | - Fernando Izquierdo
- Facultad de Farmacia, Universidad San Pablo CEU, Boadilla del Monte, Madrid, Spain
- * E-mail:
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8
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In vitro growth of microsporidia Anncaliia algerae in cell lines from warm water fish. In Vitro Cell Dev Biol Anim 2010; 47:104-13. [DOI: 10.1007/s11626-010-9366-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 10/20/2010] [Indexed: 10/18/2022]
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9
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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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10
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Barratt JLN, Harkness J, Marriott D, Ellis JT, Stark D. Importance of nonenteric protozoan infections in immunocompromised people. Clin Microbiol Rev 2010; 23:795-836. [PMID: 20930074 PMCID: PMC2952979 DOI: 10.1128/cmr.00001-10] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
There are many neglected nonenteric protozoa able to cause serious morbidity and mortality in humans, particularly in the developing world. Diseases caused by certain protozoa are often more severe in the presence of HIV. While information regarding neglected tropical diseases caused by trypanosomatids and Plasmodium is abundant, these protozoa are often not a first consideration in Western countries where they are not endemic. As such, diagnostics may not be available in these regions. Due to global travel and immigration, this has become an increasing problem. Inversely, in certain parts of the world (particularly sub-Saharan Africa), the HIV problem is so severe that diseases like microsporidiosis and toxoplasmosis are common. In Western countries, due to the availability of highly active antiretroviral therapy (HAART), these diseases are infrequently encountered. While free-living amoebae are rarely encountered in a clinical setting, when infections do occur, they are often fatal. Rapid diagnosis and treatment are essential to the survival of patients infected with these organisms. This paper reviews information on the diagnosis and treatment of nonenteric protozoal diseases in immunocompromised people, with a focus on patients infected with HIV. The nonenteric microsporidia, some trypanosomatids, Toxoplasma spp., Neospora spp., some free-living amoebae, Plasmodium spp., and Babesia spp. are discussed.
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Affiliation(s)
- J L N Barratt
- Department of Microbiology, St. Vincent's Hospital, Darlinghurst 2010, NSW, Australia.
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11
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Abstract
SUMMARYThe phylum Microspora is ancient and diverse and affects a wide range of hosts. There is unusually high use of vertical transmission and this has significant consequences for transmission and pathogenicity. Vertical transmission is associated with low pathogenesis but nevertheless can have significant impact through associated traits such as sex ratio distortion. The majority of microsporidia have mixed transmission cycles and it is not clear whether they are able to modify their phenotype according to environmental circumstances. There is a great need to understand the mechanisms controlling transmission and one of the first challenges for the genomics era is to find genes associated with life cycle stages. Similarly we cannot currently predict the ease with which these parasites might switch between host groups. Phylogenetic analysis suggests that there are strong relationships between Microsporidia and their hosts. However closer typing of parasite isolates, in relation to host range and disease phenotype, is required to assess future environmental risk from these pathogens.
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12
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Dia N, Lavie L, Méténier G, Toguebaye BS, Vivarès CP, Cornillot E. InterB multigenic family, a gene repertoire associated with subterminal chromosome regions of Encephalitozoon cuniculi and conserved in several human-infecting microsporidian species. Curr Genet 2007; 51:171-86. [PMID: 17235519 DOI: 10.1007/s00294-006-0114-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 11/08/2006] [Accepted: 11/28/2006] [Indexed: 11/30/2022]
Abstract
Microsporidia are fungi-related obligate intracellular parasites that infect numerous animals, including man. Encephalitozoon cuniculi harbours a very small genome (2.9 Mbp) with about 2,000 coding sequences (CDSs). Most repeated CDSs are of unknown function and are distributed in subterminal regions that mark the transitions between subtelomeric rDNA units and chromosome cores. A potential multigenic family (interB) encoding proteins within a size range of 579-641 aa was investigated by PCR and RT-PCR. Thirty members were finally assigned to the E. cuniculi interB family and a predominant interB transcript was found to originate from a newly identified gene on chromosome III. Microsporidian species from eight different genera infecting insects, fishes or mammals, were tested for a possible intra-phylum conservation of interB genes. Only representatives of the Encephalitozoon, Vittaforma and Brachiola genera, differing in host range but all able to invade humans, were positive. Molecular karyotyping of Brachiola algerae showed a complex set of chromosome bands, providing a haploid genome size estimate of 15-20 Mbp. In spite of this large difference in genome complexity, B. algerae and E. cuniculi shared some similar interB gene copies and a common location of interB genes in near-rDNA subterminal regions.
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Affiliation(s)
- Ndongo Dia
- Equipe Parasitologie Moléculaire et Cellulaire, Laboratoire de Biologie des Protistes, UMR CNRS 6023, Bâtiment Biologie A, Université Blaise Pascal, 63177 Aubière cedex, France
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13
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Franzen C, Nassonova ES, Schölmerich J, Issi IV. Transfer of the members of the genus Brachiola (microsporidia) to the genus Anncaliia based on ultrastructural and molecular data. J Eukaryot Microbiol 2006; 53:26-35. [PMID: 16441582 DOI: 10.1111/j.1550-7408.2005.00066.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Two microsporidian genera, AnncaliiaIssi, Krylova, & Nicolaeva 1993 and BrachiolaCali et al. 1998, possess a Nosema-type life cycle and unique cell surface ornamentations, which include precocious electron-dense coating of the plasmalemma and a variety of secretory structures deposited on the parasite surface and scattered in the host cell cytoplasm. Comparative analysis of ultrastructure of Anncaliia meligethi (the type species of the genus Anncaliia) and of B. vesicularum and B. algerae (the best-studied members of the genus Brachiola) clearly demonstrated that these microsporidia share many distinctive morphological features. The comparison of small subunit ribosomal DNA sequences showed high sequence identity of A. meligethi and B. algerae. Phylogenetic analyses indicated that the rDNA sequences of A. meligethi clustered with those of B. algerae suggesting a close relatedness of these microsporidia. The combination of molecular and morphological data provided clear evidence that these microsporidia belong to the same genus and therefore, warranted emendation of the genus Anncaliia and establishments of the following new combinations: Anncaliia vesicularum nov. comb., Anncaliia algerae nov. comb., Anncaliia connori nov. comb., and Anncaliia gambiae nov. comb. The generic name Brachiola is submerged according to the rule of priority.
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Affiliation(s)
- Caspar Franzen
- Department of Internal Medicine I, University of Regensburg, Regensburg, Germany.
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14
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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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15
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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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