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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 -
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 -
The Journal of Veterinary Medical... Feb 2016Microsporidia are obligate intracellular mitochondria-lacking pathogens that rely on host cells to grow and multiply. Microsporidia, currently classified as fungi, are... (Review)
Review
Microsporidia are obligate intracellular mitochondria-lacking pathogens that rely on host cells to grow and multiply. Microsporidia, currently classified as fungi, are ubiquitous in nature and are found worldwide. They infect a large number of mammals and are recognized as opportunistic infection agents in HIV-AIDS patients. Its importance for veterinary medicine has been unveiled in recent years through the description of clinical and subclinical forms of infection in domestic and wild animals. Domestic and wild birds may be infected by the same human microsporidia, reinforcing their zoonotic potential. Microsporidiosis in fish is prevalent and causes significant economic losses for fish farming. Some species of microsporidia have been propagated in cell cultures, which may provide conditions for the development of diagnostic techniques, understanding of pathogenesis and immune responses and for the discovery of potential therapies. Unfortunately, the cultivation of these parasites is not fully standardized in most research laboratories, especially in the veterinary field. The aim of this review is to relate the most important microsporidia of veterinary interest and demonstrate how these pathogens can be grown and propagated in cell culture for diagnostic purposes or for pathogenesis studies. Cultivation of microsporidia allowed the study of its life cycle, metabolism, pathogenesis and diagnosis, and may also serve as a repository for these pathogens for molecular, biochemical, antigenic and epidemiological studies.
Topics: Animals; Humans; Microsporidia; Microsporidiosis; Mycology; Veterinary Medicine
PubMed: 26346746
DOI: 10.1292/jvms.15-0401 -
Emerging Microbes & Infections Dec 2023Intestinal microsporidiosis is most often caused by , and to a lesser extent by species of the genus . Until now, was not clearly known to induce disease restricted to...
Intestinal microsporidiosis is most often caused by , and to a lesser extent by species of the genus . Until now, was not clearly known to induce disease restricted to the intestine, or rarely in HIV subjects or in tropical countries. We report here 11 cases of delineated intestinal microsporidioses due to diagnosed in France in non-HIV patients. Briefly, all patients were immunocompromised. They all suffered from diarrhoea, associated in nearly 50% of cases with weight loss. Concerning treatment, 5/11 patients had a discontinuation or a decrease of their immunosuppressive therapy, and 4/11 received albendazole. All patients recovered. Five different genotypes were identified based on the rRNA ITS sequence.
Topics: Humans; Encephalitozoon; Microsporidiosis; Enterocytozoon; Intestines; Feces
PubMed: 37706342
DOI: 10.1080/22221751.2023.2258997 -
Transplant Infectious Disease : An... Aug 2021Microsporidiosis has been largely reported in patients with acquired immunodeficiency syndrome, but emerged as a cause of persistent diarrhea in solid organ transplant...
BACKGROUND
Microsporidiosis has been largely reported in patients with acquired immunodeficiency syndrome, but emerged as a cause of persistent diarrhea in solid organ transplant patients.
METHODS
Through the French Microsporidiosis Network and the Groupe français de recherche en greffe de foie, we collected all microsporidiosis cases identified in liver transplant patients between 1995 and 2020 in France.
RESULTS
We identified 24 liver transplant recipients with microsporidiosis. Sex ratio was balanced and median age was 58.8 (3.5-83.5) years (there were 4 children). Microsporidiosis occurred at a median time of 3.9 (0.1-18.9) years post-transplant. Median duration of diarrhea before diagnosis was 22 days (12-45). Therapeutic care included immunosuppressive therapy changes in 20 patients, as follows: stop cyclosporine or tacrolimus (n = 2), dose reduction of cyclosporine or tacrolimus (n = 12), stop MMF (n = 5), and dose reduction of corticosteroids (n = 1). In addition, 15 patients received specific therapy against microsporidiosis: fumagillin (n = 11) or albendazole (n = 4). Median duration of treatment was 14 days (8-45 days). Finally, 7 patients had immunosuppressive treatment tapering only. Microsporidiosis was complicated by renal failure in 15 patients, requiring dialysis in one case. Two patients had infection relapse. No patient presented proven rejection within the 3 months after microsporidiosis. None of the patients died within the 3 months after microsporidiosis.
CONCLUSIONS
Microsporidiosis is a very rare infection after liver transplantation but can induce severe dehydration and renal failure. Therefore, it must be systematically sought in any case of persistent diarrhea after first line screening of frequent infectious causes.
Topics: Child; Cyclosporine; Graft Rejection; Humans; Immunosuppressive Agents; Liver Transplantation; Microsporidiosis; Middle Aged; Organ Transplantation; Retrospective Studies; Tacrolimus
PubMed: 34101311
DOI: 10.1111/tid.13665 -
The Ocular Surface Apr 2023Ocular microsporidiosis comprises two entirely different spectra of disease as keratoconjunctivitis and stromal keratitis. Microsporidial keratoconjunctivitis (MKC) has... (Review)
Review
Ocular microsporidiosis comprises two entirely different spectra of disease as keratoconjunctivitis and stromal keratitis. Microsporidial keratoconjunctivitis (MKC) has been increasingly reported in the past two decades, probably due to raised awareness, simpler diagnostic procedures, and a better understanding of the clinical presentation. It is characterized by the presence of raised, coarse, punctate, multifocal, round to oval, greyish-white corneal epithelial lesions which usually evolve into nummular scars before resolution. Conjunctivitis seen is non-purulent and of mild-moderate intensity, with mixed papillary-follicular reaction. The mode of transmission and pathogenesis is poorly understood. Despite lack of inflammatory response, uncommon associations reported were- endotheliitis, corneal edema, limbitis, uveitis, and sub-epithelial infiltrates. There has been no consensus on the management of MKC. It varies from the use of multiple antimicrobial agents to simple lubricants. The majority of the disease goes underdiagnosed or misdiagnosed and treated as adenoviral keratoconjunctivitis, with topical steroids or anti-virals empirically. Changing trends have been noticed in the pattern of infection, possibly with increasing evidence of Vittaforma corneae as causative organisms, previously reported to cause stromal keratitis. An elaborate review of the past and present literature on MKC is provided in this review article, along with gaps in knowledge, and future directions of research.
Topics: Microsporidia; Microsporidiosis; Keratoconjunctivitis; Eye
PubMed: 34419638
DOI: 10.1016/j.jtos.2021.08.008 -
Emerging Infectious Diseases Mar 2022We identified Encephalitozoon cuniculi genotype II parasites as a cause of extraintestinal microsporidiosis in 2 owners of birds also infected with E. cuniculi. Patients...
We identified Encephalitozoon cuniculi genotype II parasites as a cause of extraintestinal microsporidiosis in 2 owners of birds also infected with E. cuniculi. Patients experienced long-lasting nonspecific symptoms; the disease course was more progressive in a patient with diabetes. Our findings suggest direct bird-to-human transmission of this pathogen.
Topics: Animals; Birds; Encephalitozoon cuniculi; Encephalitozoonosis; Genotype; Humans; Microsporidiosis
PubMed: 35202528
DOI: 10.3201/eid2803.211556 -
[Zhonghua Yan Ke Za Zhi] Chinese... Nov 2022A case of keratitis caused by microsporidia infection was reported. A 57-year-old female patient, without any obvious predisposing cause, presented with eye redness, eye...
A case of keratitis caused by microsporidia infection was reported. A 57-year-old female patient, without any obvious predisposing cause, presented with eye redness, eye abrasion and vision loss for one year in the left eye. The patient was diagnosed with viral keratitis based on laboratory examinations and clinical symptoms two months ago in our hospital. He was given outpatient treatment for antivirus. Two months later, he was admitted to our hospital with worsened condition that presented with corneal ulcer. After admission, corneal scraping examination was performed for the detection of microsporidia with calcofluor white (CFW) and Ziehl-Neelsen staining, the smear revealed multiple oval spore-like structures, with acid-fast positive and showed blue fluorescence on potassium hydroxide with CFW stain, confirming a diagnosis of microsporidial keratitis in the left eye. Treatment: topical use of ofloxacin eye ointment and voriconazole eye drops was not effective, and then penetrating keratoplasty was performed, and the patient's condition was stable after surgery. At present, they are still in treatment and follow-up.
Topics: Male; Female; Humans; Middle Aged; Eye Infections, Fungal; Cornea; Keratitis; Microsporidia; Microsporidiosis
PubMed: 36348537
DOI: 10.3760/cma.j.cn112142-20211129-00565 -
Experientia Supplementum (2012) 2022The microsporidian Enterocytozoon bieneusi is an obligate intracellular pathogen that causes enteric disease (microsporidiosis) in humans and has been recorded in a wide...
The microsporidian Enterocytozoon bieneusi is an obligate intracellular pathogen that causes enteric disease (microsporidiosis) in humans and has been recorded in a wide range of animal species worldwide. The transmission of E. bieneusi is direct and likely occurs from person to person and from animal to person via the ingestion of spores in water, food, or the environment. The identification of E. bieneusi is usually accomplished by molecular means, typically using the sequence of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. Currently, ~820 distinct genotypes of E. bieneusi have been recorded in at least 210 species of vertebrates (mammals, birds, reptiles, and amphibians) or invertebrates (insects and mussels) in more than 50 countries. In this chapter, we provide a perspective on (1) clinical aspects of human microsporidiosis; (2) the genome and DNA markers for E. bieneusi as well as molecular methods for the specific and genotypic identification of E. bieneusi; (3) epidemiological aspects of E. bieneusi of animals and humans, with an emphasis on the genotypes proposed to be zoonotic, human-specific, and animal-specific; and (4) future research directions to underpin expanded molecular studies to better understand E. bieneusi and microsporidiosis.
Topics: Animals; Enterocytozoon; Genotype; Humans; Mammals; Microsporidia; Microsporidiosis; Phylogeny
PubMed: 35544010
DOI: 10.1007/978-3-030-93306-7_14