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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 -
Trends in Parasitology Aug 2021
Topics: Animals; Humans; Microsporidia; Microsporidiosis
PubMed: 33941494
DOI: 10.1016/j.pt.2021.04.003 -
Clinical Transplantation Sep 2019These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management...
Intestinal parasites including Cryptosporidium, Cyclospora, Giardia, and Microsporidia, Entamoeba histolytica, Strongyloides, Schistosomiasis, and Echinococcus: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice.
These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of intestinal parasites in the pre- and post-transplant period. Intestinal parasites are prevalent in the developing regions of the world. With increasing travel to and from endemic regions, changing immigration patterns, and the expansion of transplant medicine in developing countries, they are increasingly recognized as a source of morbidity and mortality in solid-organ transplant recipients. Parasitic infections may be acquired from the donor allograft, from reactivation, or from de novo acquisition post-transplantation. Gastrointestinal multiplex assays have been developed; some of the panels include testing for Cryptosporidium, Cyclospora, Entamoeba histolytica, and Giardia, and the performance is comparable to conventional methods. A polymerase chain reaction test, not yet widely available, has also been developed to detect Strongyloides in stool samples. New recommendations have been developed to minimize the risk of Strongyloides donor-derived events. Deceased donors with epidemiological risk factors should be screened for Strongyloides and recipients treated if positive as soon as the results are available. New therapeutic agents and studies addressing the optimal treatment regimen for solid-organ transplant recipients are unmet needs.
Topics: Animals; Anthelmintics; Cryptosporidiosis; Cryptosporidium; Cyclospora; Cyclosporiasis; Donor Selection; Echinococcosis; Echinococcus; Entamoeba histolytica; Entamoebiasis; Giardia; Giardiasis; Helminths; Humans; Intestinal Diseases, Parasitic; Microsporidia; Microsporidiosis; Organ Transplantation; Practice Guidelines as Topic; Schistosoma; Schistosomiasis; Societies, Medical; Strongyloides; Strongyloidiasis; Tissue Donors; Transplant Recipients
PubMed: 31145496
DOI: 10.1111/ctr.13618 -
Journal of Clinical Microbiology Nov 2014Microsporidia are highly specialized obligate intracellular organisms that are closely related to fungi. Although traditionally associated with diarrheal illness in... (Review)
Review
Microsporidia are highly specialized obligate intracellular organisms that are closely related to fungi. Although traditionally associated with diarrheal illness in patients with AIDS, extraintestinal infections involving various organs have been reported with increasing frequency in the past decade, particularly in immunocompromised hosts. Diagnosis is usually accomplished by light microscopic identification of spores in body fluids and tissues, using a variety of stains. Transmission electron microscopy, immunofluorescence assays, or molecular methods are necessary for identification to the genus and species level. Early diagnosis is essential for preventing the significant associated morbidity and mortality of extraintestinal microsporidiosis.
Topics: Humans; Immunocompromised Host; Microbiological Techniques; Microsporidia; Microsporidiosis
PubMed: 24829239
DOI: 10.1128/JCM.00971-14 -
Current Opinion in Microbiology Aug 2015Microsporidia comprise one of the largest groups of obligate intracellular pathogens and can infect virtually all animals, but host response to these fungal-related... (Review)
Review
Microsporidia comprise one of the largest groups of obligate intracellular pathogens and can infect virtually all animals, but host response to these fungal-related microbes has been poorly understood. Several new studies of the host transcriptional response to microsporidia infection have found infection-induced regulation of genes involved in innate immunity, ubiquitylation, metabolism, and hormonal signaling. In addition, microsporidia have recently been shown to exploit host recycling endocytosis for exit from intestinal cells, and to interact with host degradation pathways. Microsporidia infection has also been shown to profoundly affect behavior in insect hosts. Altogether, these and other recent findings are providing much-needed insight into the underlying mechanisms of microsporidia interaction with host animals.
Topics: Animals; Disease Models, Animal; Host-Pathogen Interactions; Humans; Immunity, Innate; Insecta; Microsporidia; Microsporidiosis
PubMed: 25847674
DOI: 10.1016/j.mib.2015.03.006 -
Revista Chilena de Infectologia :... 2018
Topics: Microsporidia; Microsporidiosis
PubMed: 29652974
DOI: 10.4067/s0716-10182018000100073 -
Clinics in Laboratory Medicine Jun 2015Infection by the ingested pathogens of microsporidia occur primarily in immunosuppressed patients (including untreated HIV/AIDS) and are diagnosed by stool examination,... (Review)
Review
Infection by the ingested pathogens of microsporidia occur primarily in immunosuppressed patients (including untreated HIV/AIDS) and are diagnosed by stool examination, small bowel biopsy with special stains, or electron microscopy (for definitive speciation), or by various molecular techniques. Although electron microscopy has been the definitive diagnostic tool for speciation, genetic sequencing increasingly provides the definitive diagnosis for new species, such as Anncaliia algerae. Further genetic sequencing of the common pathogens may allow for the development of advanced molecular diagnostics providing high diagnostic sensitivity and throughput.
Topics: Diagnosis, Differential; Feces; Humans; Immunocompromised Host; Microsporidia; Microsporidiosis
PubMed: 26004651
DOI: 10.1016/j.cll.2015.02.011 -
Developmental and Comparative Immunology Jun 2018Microsporidia are a group of fungi-like intracellular and unicellular parasites, which infect nearly all animals. As "master parasites", over 1400 microsporidian species... (Review)
Review
Microsporidia are a group of fungi-like intracellular and unicellular parasites, which infect nearly all animals. As "master parasites", over 1400 microsporidian species have been described to date. Microsporidia infections in economical invertebrates (e.g., silkworm, shrimp) cause huge financial losses, while other microsporidia infections in daphnia, nematode, locust, honeybee and mosquito play important roles in the regulation of their population size. Research investigating invertebrate host responses following microsporidia infections has yielded numerous interesting results, especially pertaining to the innate immune response to these pathogens. In this review, we comparatively summarize the invertebrate host responses to various microsporidia infections. We discuss numerous critical events in host responses including ubiquitin-mediated resistance, production of reactive oxygen species, melanization and innate immune pathways, and the increased basic metabolism and the accumulation of juvenile hormone in infected hosts. Recent studies progressing our understanding of microsporidia infection are also highlighted. Collectively, these advances shed more light on general rules of invertebrate host immune responses and pathogenesis mechanisms of microsporidia, and concurrently offer valuable clues for further research on the crosstalk between hosts and intracellular pathogens.
Topics: Animals; Host-Pathogen Interactions; Humans; Immunity, Innate; Insect Proteins; Invertebrates; Microsporidia; Microsporidiosis; Pest Control, Biological; Phylogeny; Respiratory Burst; Ubiquitin
PubMed: 29428490
DOI: 10.1016/j.dci.2018.02.004 -
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 -
Advances in Parasitology 2021Enterocytozoon bieneusi is a microsporidian microorganism that causes intestinal disease in animals including humans. E. bieneusi is an obligate intracellular pathogen,... (Review)
Review
Enterocytozoon bieneusi is a microsporidian microorganism that causes intestinal disease in animals including humans. E. bieneusi is an obligate intracellular pathogen, typically causing severe or chronic diarrhoea, malabsorption and/or wasting. Currently, E. bieneusi is recognised as a fungus, although its exact classification remains contentious. The transmission of E. bieneusi can occur from person to person and/or animals to people. Transmission is usually via the faecal-oral route through E. bieneusi spore-contaminated water, environment or food, or direct contact with infected individuals. Enterocytozoon bieneusi genotypes are usually identified and classified by PCR-based sequencing of the internal transcribed spacer region (ITS) of nuclear ribosomal DNA. To date, ~600 distinct genotypes of E. bieneusi have been recorded in ~170 species of animals, including various orders of mammals and reptiles as well as insects in >40 countries. Moreover, E. bieneusi has also been found in recreational water, irrigation water, and treated raw- and waste-waters. Although many studies have been conducted on the epidemiology of E. bieneusi, prevalence surveys of animals and humans are scant in some countries, such as Australia, and transmission routes of individual genotypes and related risk factors are poorly understood. This article/chapter reviews aspects of the taxonomy, biology and epidemiology of E. bieneusi; the diagnosis, treatment and prevention of microsporidiosis; critically appraises the naming system for E. bieneusi genotypes as well as the phylogenetic relationships of these genotypes; provides new insights into the prevalence and genetic composition of E. bieneusi populations in animals in parts of Australia using molecular epidemiological tools; and proposes some areas for future research in the E. bieneusi/microsporidiosis field.
Topics: Animals; Enterocytozoon; Food Microbiology; Humans; Microsporidiosis; Prevalence; Water Microbiology; Zoonoses
PubMed: 33482973
DOI: 10.1016/bs.apar.2020.10.001