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Clinical Microbiology Reviews Dec 2021Microsporidia are obligate intracellular pathogens identified ∼150 years ago as the cause of pébrine, an economically important infection in silkworms. There are...
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.
Topics: Gastrointestinal Diseases; Humans; Microsporidia; Microsporidiosis; Phylogeny; Prevalence
PubMed: 34190570
DOI: 10.1128/CMR.00010-20 -
Current Biology : CB Sep 2023In this Quick guide, Thomas Whelan and Naomi Fast introduce the microsporidia: obligate intracellular parasites with the most extremely reduced genomes known in...
In this Quick guide, Thomas Whelan and Naomi Fast introduce the microsporidia: obligate intracellular parasites with the most extremely reduced genomes known in eukaryotes.
Topics: Microsporidia; Eukaryota
PubMed: 37751700
DOI: 10.1016/j.cub.2023.06.076 -
Trends in Parasitology Aug 2021
Topics: Animals; Humans; Microsporidia; Microsporidiosis
PubMed: 33941494
DOI: 10.1016/j.pt.2021.04.003 -
Current Protocols May 2024Nematodes are naturally infected by the fungal-related pathogen microsporidia. These ubiquitous eukaryotic parasites are poorly understood, despite infecting most types...
Nematodes are naturally infected by the fungal-related pathogen microsporidia. These ubiquitous eukaryotic parasites are poorly understood, despite infecting most types of animals. Identifying novel species of microsporidia and studying them in an animal model can expedite our understanding of their infection biology and evolution. Nematodes present an excellent avenue for pursuing such work, as they are abundant in the environment and many species are easily culturable in the laboratory. The protocols presented here describe how to isolate bacterivorous nematodes from rotting substrates, screen them for microsporidia infection, and molecularly identify the nematode and microsporidia species. Additionally, we detail how to remove environmental contaminants and generate a spore preparation of microsporidia from infected samples. We also discuss potential pitfalls and provide suggestions on how to mitigate them. These protocols allow for the identification of novel microsporidia species, which can serve as an excellent starting point for genomic analysis, determination of host specificity, and infection characterization. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Gathering samples Support Protocol 1: Generating 10× and 40× Escherichia coli OP50 and seeding NGM plates Basic Protocol 2: Microsporidia screening, testing for Caenorhabditis elegans susceptibility, and sample freezing Basic Protocol 3: DNA extraction, PCR amplification, and sequencing to identify nematode and microsporidia species Basic Protocol 4: Removal of contaminating microbes and preparation of microsporidia spores Support Protocol 2: Bleach-synchronizing nematodes.
Topics: Animals; Microsporidia; Nematoda; Caenorhabditis elegans; DNA, Fungal; Polymerase Chain Reaction; Microsporidiosis; Spores, Fungal
PubMed: 38727641
DOI: 10.1002/cpz1.1035 -
Experientia Supplementum (2012) 2022Microsporidia are a group of pathogens, which can pose severe risks to the immunocompromised population, such as HIV-infected individuals or organ transplant recipients....
Microsporidia are a group of pathogens, which can pose severe risks to the immunocompromised population, such as HIV-infected individuals or organ transplant recipients. Adaptive immunity has been reported to be critical for protection, and mice depleted of T cells are unable to control these infections. In a mouse model of infection, CD8 T cells have been found to be the primary effector cells and are responsible for protecting the infected host. Also, as infection is acquired via a peroral route, CD8 T cells in the gut compartment act as a first line of defense against these pathogens. Thus, generation of a robust CD8 T-cell response exhibiting polyfunctional ability is critical for host survival. In this chapter, we describe the effector CD8 T cells generated during microsporidia infection and the factors that may be essential for generating protective immunity against these understudied but significant pathogens. Overall, this chapter will highlight the necessity for a better understanding of the development of CD8 T-cell responses in gut-associated lymphoid tissue (GALT) and provide some insights into therapies that may be used to restore defective CD8 T-cell functionality in an immunocompromised situation.
Topics: Adaptive Immunity; Animals; CD8-Positive T-Lymphocytes; Immunity, Mucosal; Mice; Microsporidia; Microsporidiosis
PubMed: 35544009
DOI: 10.1007/978-3-030-93306-7_13 -
Parasitology Research May 2020The reduction and specialization of the energy metabolism system is a common trait in the evolution of intracellular parasites. One group of fungi-related parasites, the... (Review)
Review
The reduction and specialization of the energy metabolism system is a common trait in the evolution of intracellular parasites. One group of fungi-related parasites, the Microsporidia, seems to have developed this trait far more than other eukaryotes. As an extreme adaptation for a parasitic lifestyle, some of them have completely lost the ability to synthesize ATP, relying heavily upon the metabolic processes of host cells to ensure their own development and reproduction. For a long time, only fragmentary data on the functioning and evolution of the energy metabolism system in microsporidia was available. However, the recent discovery of microsporidia-related microorganisms, the Cryptomycota and Aphelida, alongside with the genome sequencing and new data about basal groups in the Microsporidia has shed new light on this problem. Here, we review recent data about functioning of the energy metabolism system in microsporidia and closely related organisms, and discuss possible evolutionary pathways in the group.
Topics: Energy Metabolism; Evolution, Molecular; Fungi; Genome, Fungal; Host-Parasite Interactions; Loss of Function Mutation; Microsporidia; Phylogeny
PubMed: 32200463
DOI: 10.1007/s00436-020-06657-9 -
Cellular Microbiology Nov 2020Microsporidia are a large group of fungal-related obligate intracellular parasites. They are responsible for infections in humans as well as in agriculturally and... (Review)
Review
Microsporidia are a large group of fungal-related obligate intracellular parasites. They are responsible for infections in humans as well as in agriculturally and environmentally important animals. Although microsporidia are abundant in nature, many of the molecular mechanisms employed during infection have remained enigmatic. In this review, we highlight recent work showing how microsporidia invade, proliferate and exit from host cells. During invasion, microsporidia use spore wall and polar tube proteins to interact with host receptors and adhere to the host cell surface. In turn, the host has multiple defence mechanisms to prevent and eliminate these infections. Microsporidia encode numerous transporters and steal host nutrients to facilitate proliferation within host cells. They also encode many secreted proteins which may modulate host metabolism and inhibit host cell defence mechanisms. Spores exit the host in a non-lytic manner that is dependent on host actin and endocytic recycling proteins. Together, this work provides a fuller picture of the mechanisms that these fascinating organisms use to infect their hosts.
Topics: Adaptive Immunity; Animals; Cell Proliferation; Fungal Proteins; Host-Pathogen Interactions; Humans; Immunity, Innate; Microsporidia; Microsporidiosis; Spores, Fungal; Stress, Physiological
PubMed: 32748538
DOI: 10.1111/cmi.13247 -
Materials Science & Engineering. C,... Jun 2021Many approaches and technologies have been developed as treatments for microsporidian, infections but effective, broad-spectrum, and sustainable therapeutic approaches...
Many approaches and technologies have been developed as treatments for microsporidian, infections but effective, broad-spectrum, and sustainable therapeutic approaches have not been found. Silver nanoparticles (AgNPs) have antimicrobial activity and are widely used against many different pathogens. AgNPs provide an opportunity to develop formulations that will control microsporidia. In this study, we synthesized AgNPs via a chemical reduction method and evaluated their formation, morphology, and stability using transmission electron microscopy (TEM) and ultraviolet spectroscopy analysis. We verified that AgNPs could disrupt the spore cell membrane and spore germination of microsporidia Nosema bombycis. This resulted in the release of microsporidia nucleic acids, proteins, and respiratory chain enzymes. The anti-microsporidia activity of AgNPs was studied by measuring the silkworm larvae survival rate and spore genome replication after microsporidia infection. AgNPs have anti-microsporidian activity and could be effective components of formulations for treating or preventing microsporidia infection.
Topics: Animals; Bombyx; Metal Nanoparticles; Nosema; Silver
PubMed: 33965113
DOI: 10.1016/j.msec.2021.112106 -
Experientia Supplementum (2012) 2022Microsporidia are a large phylum of obligate intracellular parasites that infect an extremely diverse range of animals and protists. In this chapter, we review what is... (Review)
Review
Microsporidia are a large phylum of obligate intracellular parasites that infect an extremely diverse range of animals and protists. In this chapter, we review what is currently known about microsporidia host specificity and what factors influence microsporidia infection. Extensive sampling in nature from related hosts has provided insight into the host range of many microsporidia species. These field studies have been supported by experiments conducted in controlled laboratory environments which have helped to demonstrate host specificity. Together, these approaches have revealed that, while examples of generalist species exist, microsporidia specificity is often narrow, and species typically infect one or several closely related hosts. For microsporidia to successfully infect and complete their life cycle within a compatible host, several steps must occur, including spore germination, host cell invasion, and proliferation of the parasite within the host tissue. Many factors influence infection, including temperature, seasonality, nutrient availability, and the presence or absence of microbes, as well as the developmental stage, sex, and genetics of the host. Several studies have identified host genomic regions that influence resistance to microsporidia, and future work is likely to uncover molecular mechanisms of microsporidia host specificity in more detail.
Topics: Animals; Host Specificity; Life Cycle Stages; Microsporidia; Microsporidiosis
PubMed: 35544000
DOI: 10.1007/978-3-030-93306-7_4 -
Experientia Supplementum (2012) 2022There have been several significant new findings regarding Microsporidia of fishes over the last decade. Here we provide an update on new taxa, new hosts and new...
There have been several significant new findings regarding Microsporidia of fishes over the last decade. Here we provide an update on new taxa, new hosts and new diseases in captive and wild fishes since 2013. The importance of microsporidiosis continues to increase with the rapid growth of finfish aquaculture and the dramatic increase in the use of zebrafish as a model in biomedical research. In addition to reviewing new taxa and microsporidian diseases, we include discussions on advances with diagnostic methods, impacts of microsporidia on fish beyond morbidity and mortality, novel findings with transmission and invertebrate hosts, and a summary of the phylogenetics of fish microsporidia.
Topics: Animals; Aquaculture; Microsporidia; Microsporidiosis; Phylogeny; Zebrafish
PubMed: 35544007
DOI: 10.1007/978-3-030-93306-7_11