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Advances in Parasitology 2001The microsporidia are an ancient and diverse group of protists which have many unusual characteristics. These include prokaryotic-like 70s ribosomes, enclosed nuclear... (Review)
Review
The microsporidia are an ancient and diverse group of protists which have many unusual characteristics. These include prokaryotic-like 70s ribosomes, enclosed nuclear division, a lack of mitochondria and complex life cycles which frequently involve vertical transmission. This use of vertical transmission is unparalleled by other protists and is seen only among bacterial endosymbionts and sex ratio distorters and in host cell organelles. Transovarially transmitted microsporidia can have unusual and profound effects on host population sex ratios. We here consider the mechanisms of transovarial transmission and its implications for parasite evolution. We review parasite/host relationships and the evolution of virulence under transovarial transmission and consider the implications of these parasites for host ecology and evolution.
Topics: Animals; Arthropods; Biological Evolution; Female; Host-Parasite Interactions; Male; Microsporidia; Microsporidiosis; Ovary; Sex Ratio; Virulence
PubMed: 11013755
DOI: 10.1016/s0065-308x(01)48005-5 -
The Journal of Eukaryotic Microbiology Sep 2020On their spore surfaces, Microsporidia often develop a canopy of filaments with characteristics of intermediate filaments (IF), as we demonstrated in previous studies on...
On their spore surfaces, Microsporidia often develop a canopy of filaments with characteristics of intermediate filaments (IF), as we demonstrated in previous studies on Thelohania sp., Ameson michaelis, and Spraguea lophii. Genomic studies indicate that among invertebrates, lamins that may localize in the cytoplasm or nucleus, are the only known IF type. These IFs can bind to the substrate containing cell adhesion molecules (CAMs) cadherins, associated with β and γ catenins. The objects of this study were to determine whether microsporidia have CAMs with the attached IFs on their envelopes and to find out if these proteins are provided by the host. An examination was made for localization of lamins and CAMs on the spores of the mentioned above species and Anncaliia algerae, plus in the host animals. Then, we determined whether the spores of A. michaelis and A. algerae could bind vertebrate nuclear lamin onto the spore surface. We also tested transgenic Drosophila melanogaster stocks bearing cadherin-GFP to see whether developing A. algerae parasites in these hosts could acquire host CAMs. The tests were positive for all these experiments. We hypothesize that microsporidia are able to acquire host lamin IFs and cell adhesion catenin-cadherin complexes from the host.
Topics: Animals; Cadherins; Catenins; Cell Adhesion; Drosophila melanogaster; Host-Parasite Interactions; Intermediate Filaments; Lamins; Microscopy, Electron, Transmission; Microsporidia
PubMed: 32498127
DOI: 10.1111/jeu.12811 -
Journal of Infection in Developing... May 2021Human microsporidiosis represents an important and rapidly emerging opportunistic disease. The present study investigated the prevalence of microsporidia among HIV...
INTRODUCTION
Human microsporidiosis represents an important and rapidly emerging opportunistic disease. The present study investigated the prevalence of microsporidia among HIV positive and HIV negative patients with or without diarrhoea in Vhembe and Mopani Districts in the Limpopo Province.
METHODOLOGY
A total of 170 stool samples were collected from these patients and microsporidia species was detected using a Real-Time PCR targeting a conserved region of the small ribosomal subunit rRNA (SSU-rRNA) gene of Enterocytozoon bieneusi, Encephalitozoon intestinalis, Encephalitozoon hellem, and Encephalitozoon cuniculi.
RESULTS
Fifty six (32.9%) were positive for microsporidia. The prevalence was higher in HIV negative patients (36.6%) while 24.1% of patients who were HIV positive had microsporidia. Microsporidia was more common among patients aged between 1 and 10 years (52.6%). However among the HIV positive patients, microsporidia prevalence was higher among those that were not taking antiretrovirals (ARVs) compared to those who were on ARVs, (36.6%) and (24.1%), respectively. Microsporidia was also noted to be significantly associated with diarrheal and stomach pains; p = 0.02 and p = 0.048, respectively. Furthermore, microsporidia infections was more prevalent among patients who had animals at home (p = 0.037).
CONCLUSIONS
Study has shown a high prevalence of microsporidia among patients attending primary health centers in the Mopani District for the first time. Prevalence of microsporidia was higher among HIV negative and HIV positive patients who were not on ARV treatment. Keeping animals in the household appeared to be a risk of getting infected with microsporidia. Further studies are needed to determine the genetic characteristics of these organisms in the study population.
Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Demography; Feces; Female; HIV Infections; Humans; Infant; Male; Microsporidia; Microsporidiosis; Middle Aged; Prevalence; South Africa; Young Adult
PubMed: 34106896
DOI: 10.3855/jidc.12988 -
Virulence 2011Microsporidia are obligate intracellular parasites that have evolved an elaborate mechanism for invading animal host cells, but which have otherwise greatly reduced... (Review)
Review
Microsporidia are obligate intracellular parasites that have evolved an elaborate mechanism for invading animal host cells, but which have otherwise greatly reduced biological complexity. In particular, microsporidia possess the smallest autonomous nuclear genomes known (as opposed to nucleus derived organelles, or nucleomorphs), and their 'anaerobic' core carbon metabolism is severely limited. Here we compare the extremes to which these two characteristics have evolved, and contrast how their reduction has either proceeded within the constraints of an unchanging set of functions, or has reduced the functional capabilities of the cell. Specifically, we review how the smallest known nuclear genome, the 2.3 Mbp genome of Encephalitozoon intestinalis, has arrived at this diminutive form without significantly affecting its protein-coding complexity in comparison with closely related, larger genomes. In contrast to this, Enterocytozoon bieneusi has a relatively large genome, and yet has lost all enzymes necessary to synthesize ATP from sugar - imposing a major limitation on the functional capabilities of the cell. The extremity of this reduction demands a re-evaluation of metabolic processes in other microsporidia: although pathways such as glycolysis are present, comparative genomic data suggest they may not play the cellular role that they are generally assumed to play.
Topics: Animals; Fungal Proteins; Genome, Fungal; Humans; Microsporidia; Microsporidiosis
PubMed: 21217203
DOI: 10.4161/viru.2.1.14606 -
Frontiers in Cellular and Infection... 2021Microsporidia are a group of spore-forming, fungus-related pathogens that can infect both invertebrates and vertebrates including humans. The primary infection site is...
Microsporidia are a group of spore-forming, fungus-related pathogens that can infect both invertebrates and vertebrates including humans. The primary infection site is usually digestive tract, but systemic infections occur as well and cause damages to organs such as lung, brain, and liver. The systemic spread of microsporidia may be intravascular, requiring attachment and colonization in the presence of shear stress. Von Willebrand Factor (VWF) is a large multimeric intravascular protein and the key attachment sites for platelets and coagulation factors. Here in this study, we investigated the interactions between VWF and microsporidia (), and the modulating effects on after VWF binding. Microfluidic assays showed that binds to ultra-large VWF strings under shear stress. germination assay and infection assay proved that significantly increased the rates of germination and infection, and these effects would be reversed by VWF blocking antibody. Mass spectrometry analysis further revealed that VWF-incubation altered various aspects of including metabolic activity, levels of structural molecules, and protein maturation. Our findings demonstrated that VWF can bind microsporidia in circulation, and modulate its pathogenicity, including promoting germination and infection rate. VWF facilitates microsporidia intravascular spreading and systemic infection.
Topics: Animals; Encephalitozoon; Humans; Microsporidia; von Willebrand Factor
PubMed: 34095003
DOI: 10.3389/fcimb.2021.694957 -
Folia Parasitologica 1994Heterosporous (polymorphic) microsporidia in mosquitoes are characterized by intricate life cycles involving multiple spore types responsible for horizontal (per os) and... (Review)
Review
Heterosporous (polymorphic) microsporidia in mosquitoes are characterized by intricate life cycles involving multiple spore types responsible for horizontal (per os) and vertical (transovarial) transmission. They affect two generations of the mosquito and some involve an obligate intermediate host. Heterosporous microsporidia are generally very host and tissue specific with complex developmental sequences comprised of unique stages and events. Full details on the intricate relationships between heterosporous microsporidia and their mosquito hosts have only recently been elucidated. Edhazardia aedis (Kudo, 1930) and Culicospora magna (Kudo, 1920) have developmental sequences in larvae that involve gametogony followed by plasmogamy and nuclear association to form diplokarya. These diplokaryotic stages then undergo karyogamy and form binucleate spores responsible for transovarial transmission. In the filial generation, haplosis occurs as a result of nuclear dissociation to produce uninucleate spores infectious to larval mosquitoes. Amblyospora californica (Kellen et Lipa, 1960) has similar sequences except that haplosis is by meiosis to produce spores infectious for a copepod intermediate host. A third spore type is formed in the intermediate host responsible for infection in a new generation of the mosquito host.
Topics: Animals; Culicidae; Female; Host-Parasite Interactions; Male; Microscopy, Electron; Microsporida
PubMed: 7927065
DOI: No ID Found -
Parasitology Research Jun 2019We describe the type species of a novel genus of microsporidian parasite, Pseudokabatana alburnus n. gen. n. sp., infecting the liver of topmouth culter, Culter alburnus... (Review)
Review
We describe the type species of a novel genus of microsporidian parasite, Pseudokabatana alburnus n. gen. n. sp., infecting the liver of topmouth culter, Culter alburnus Basilewsky, 1855, from Lake Poyang off Xingzi county, Jiangxi Province, China. The parasite elicits formation of spherical xenomas of up to 1.2 mm in diameter containing all observed life stages from early merogonal plasmodia to mature spores contained within the cytoplasm of host hepatocytes. Merogonal plasmodia existed in direct contact with the host cytoplasm and contained up to 20 visible nuclei. Plasmotomy of the multinucleate plasmodium led to formation of uninucleate cells in which the nucleus underwent further division to form bi-nucleate presporonts, sporonts (defined by cells with a thickened endospore) and eventually sporoblasts (containing pre-cursors of the spore extrusion apparatus). Mature spores were pyriform and monokaryotic, measuring 2.3 ± 0.19 μm long and 1.3 ± 0.10 μm wide. Spores possessed a bipartite polaroplast and 5-6 coils of a polar filament, in a single rank. The obtained partial SSU rRNA gene sequence, 1383 bp in length, did not match any of microsporidia available in GenBank. SSU rDNA-based phylogenetic analysis indicated a new taxon branching with Kabatana rondoni, a parasite infecting the skeletal muscle of Gymnorhamphichthys rondoni from the Amazon River. Due to different host and tissue tropism, the novel taxon did not fit the diagnostic criteria for the genus Kabatana. Further, based on SSU rDNA-inferred phylogenetic analyses, different ultrastructural features of developmental stages, and ecological considerations, a new genus Pseudokabatana and type species Pseudokabatana alburnus n. sp. was erected for the parasite in topmouth culter.
Topics: Animals; China; Cyprinidae; DNA, Ribosomal; Fish Diseases; Liver; Microsporidia; Microsporidiosis; Phylogeny
PubMed: 30976967
DOI: 10.1007/s00436-019-06303-z -
Tsitologiia 2016Microsporidia comprise a group of fungi-related obligate intracellular eukaryotic pathogens with extremely wide host range: from protists to mammals. Adaptation to... (Review)
Review
Microsporidia comprise a group of fungi-related obligate intracellular eukaryotic pathogens with extremely wide host range: from protists to mammals. Adaptation to intracellular parasitism drives these parasites towards significant reduction and modification of the genome and functional apparatus, which causes extreme dependence on the host cell, as well as sophisticated host-parasite relationships. In this review we summarize our results and recent literature data about microsporidian interactions with the host at the cellular level. The impacts of these pathogens to infected cells include induction of hypertrophy, restructuring and modification of the cytoskeleton and the vesicular transport system of the host cells. Microsporidians also able to stimulate the metabolic processes in the infected cells and inhibit their defensive reactions. The main tool of the direct regulatory impact of microsporidia on the host cell apparently is the secretion of the special protein effectors capable to interfere to regulatory and signaling pathways of the host cell.
Topics: Animals; Cell Physiological Phenomena; Cytoplasm; Host-Parasite Interactions; Microsporidia
PubMed: 30183199
DOI: No ID Found -
PLoS Neglected Tropical Diseases Dec 2023Microsporidia are fungal obligate intracellular pathogens, which infect most animals and cause microsporidiosis. Despite the serious threat that microsporidia pose to...
Microsporidia are fungal obligate intracellular pathogens, which infect most animals and cause microsporidiosis. Despite the serious threat that microsporidia pose to humans and agricultural animals, few drugs are available for the treatment and control of microsporidia. To identify novel inhibitors, we took advantage of the model organism Caenorhabditis elegans infected with its natural microsporidian Nematocida parisii. We used this system to screen the Pandemic Response Box, a collection of 400 diverse compounds with known antimicrobial activity. After testing these compounds in a 96-well format at high (100 μM) and low (40 μM) concentrations, we identified four inhibitors that restored the ability of C. elegans to produce progeny in the presence of N. parisii. All four compounds reduced the pathogen load of both N. parisii and Pancytospora epiphaga, a C. elegans-infecting microsporidia related to human-infecting species. One of these compounds, a known inhibitor of a viral protease, MMV1006203, inhibited invasion and prevented the firing of spores. A bis-indole derivative, MMV1593539, decreased spore viability. An albendazole analog, MMV1782387, inhibited proliferation of N. parisii. We tested albendazole as well as 5 other analogs and observed that MMV1782387 was amongst the strongest inhibitors of N. parisii and displayed the least host toxicity. Our study further demonstrates the effectiveness of the C. elegans-N. parisii system for discovering microsporidia inhibitors and the compounds we identified provide potential scaffolds for anti-microsporidia drug development.
Topics: Animals; Humans; Caenorhabditis elegans; Albendazole; Pandemics; Microsporidia; Microsporidiosis
PubMed: 38064503
DOI: 10.1371/journal.pntd.0011806 -
The Journal of Eukaryotic Microbiology Nov 2018Some protists with microsporidian-like cell biological characters, including Mitosporidium, Paramicrosporidium, and Nucleophaga, have SSU rRNA gene sequences that are...
Some protists with microsporidian-like cell biological characters, including Mitosporidium, Paramicrosporidium, and Nucleophaga, have SSU rRNA gene sequences that are much less divergent than canonical Microsporidia. We analysed the phylogenetic placement and environmental diversity of microsporidian-like lineages that group near the base of the fungal radiation and show that they group in a clade with metchnikovellids and canonical microsporidians, to the exclusion of the clade including Rozella, in line with what is currently known of their morphology and cell biology. These results show that the phylogenetic scope of Microsporidia has been greatly underestimated. We propose that much of the lineage diversity previously thought to be cryptomycotan/rozellid is actually microsporidian, offering new insights into the evolution of the highly specialized parasitism of canonical Microsporidia. This insight has important implications for our understanding of opisthokont evolution and ecology, and is important for accurate interpretation of environmental diversity. Our analyses also demonstrate that many opisthosporidian (aphelid+rozellid+microsporidian) SSU V4 OTUs from Neotropical forest soils group with the short-branching Microsporidia, consistent with the abundance of their protist and arthropod hosts in soils. This novel diversity of Microsporidia provides a unique opportunity to investigate the evolutionary origins of a highly specialized clade of major animal parasites.
Topics: Animals; Arthropods; Biodiversity; Chytridiomycota; DNA, Fungal; Ecology; Eukaryota; Evolution, Molecular; Flagella; Genome, Fungal; Lichens; Microsporidia; Phylogeny; Soil Microbiology
PubMed: 29603494
DOI: 10.1111/jeu.12519