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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 -
Journal of Cutaneous Pathology Jul 2020Microsporidia are a group of obligate intracellular parasites that naturally infect domestic and wild animals. Human microsporidiosis is an increasingly recognized...
Microsporidia are a group of obligate intracellular parasites that naturally infect domestic and wild animals. Human microsporidiosis is an increasingly recognized multisystem opportunistic infection. The clinical manifestations are diverse with diarrhea being the most common presenting symptom. We present a 52-year-old woman with a history of amyopathic dermatomyositis complicated by interstitial lung disease managed with mycophenolate mofetil and hydroxychloroquine who presented with a 7-month history of recurrent subcutaneous nodules as well as intermittent diarrhea and chronic sinusitis. A punch biopsy showed superficial and deep lymphocytic and granulomatous dermatitis with focal necrosis. Tissue stains for microorganisms revealed oval 1 to 3 μm spores within the necrotic areas in multiple tissue stains. Additional studies at the Centers for Disease Control and Prevention confirmed cutaneous microsporidiosis. This case is one of very few confirmed examples of cutaneous microsporidiosis reported in the literature.
Topics: Dermatomycoses; Dermatomyositis; Enzyme Inhibitors; Female; Humans; Hydroxychloroquine; Immunocompromised Host; Lung Diseases, Interstitial; Microsporidiosis; Middle Aged; Mycophenolic Acid
PubMed: 32125011
DOI: 10.1111/cup.13674 -
The Veterinary Record Jul 2023There is a relative paucity of data examining the prevalence of renal pathology in wild rabbits.
BACKGROUND
There is a relative paucity of data examining the prevalence of renal pathology in wild rabbits.
METHODS
Sixty-two wild rabbits that had been shot for population control in Cambridgeshire, UK, underwent postmortem examination, including macroscopic and microscopic renal assessment.
RESULTS
The majority (82%) of the animals had macroscopically and microscopically normal kidneys. One animal (1.6%) had severe perirenal abscessation. Pasteurella spp. was isolated from this lesion. Ten rabbits (16%) had microscopic renal pathology comprising minimal to mild renal inflammation or fibrosis. No Encephalitozoon cuniculi organisms were detected histologically.
LIMITATIONS
The sample population was composed of shot rabbits, so the probability of detecting moribund individuals was reduced. Extrapolation of these data to the wider UK wild rabbit population may be limited as rabbits were shot at two sites within a 3 km radius of each other.
CONCLUSION
Renal pathology is rare in the population examined.
Topics: Animals; Rabbits; Kidney; Encephalitozoon cuniculi; Brain; Encephalitozoonosis
PubMed: 37095703
DOI: 10.1002/vetr.2948 -
Infection, Genetics and Evolution :... Nov 2019Microsporidia are composed of a highly diverse group of single-celled, obligate intracellular fungi that colonize an extremely wide range of other eukaryotes, among... (Review)
Review
Microsporidia are composed of a highly diverse group of single-celled, obligate intracellular fungi that colonize an extremely wide range of other eukaryotes, among which Enterocytozoon bieneusi is the most common species responsible for human microsporidiasis. Genotyping of E. bieneusi based on sequence analysis of the ribosomal internal transcribed spacer (ITS) has recognized ~500 genotypes in humans and a great variety of other mammals and birds. Those genotypes vary in genetic or hereditary characteristics and form 11 genetic groups in phylogenetic analysis of the ITS nucleotide sequences. Some of genotypes in Group 1 (e.g., D, EbpC, and type IV) and Group 2 (e.g., BEB4, BEB6, I, and J) have broad host and geographic ranges, constituting a major risk for zoonotic or cross-species transmission. By contrast, host specificity seems common in Group 3 to Group 11 whose members appear well adapted to specific hosts and thus would have minimal or unknown effects on public health. Multilocus sequence typing using the ITS, three microsatellites MS1, MS3, and MS7, and one minisatellite MS4, and population genetic analysis of Group 1 isolates reveal the occurrence of clonality, potential host adaptation, and population differentiation of E. bieneusi in various hosts. Nonetheless, it is still highly desirable to explore novel genetic markers with enough polymorphisms, to type complex or unstructured E. bieneusi populations of various host species and geographic origins, notably those belonging to Group 2 to Group 11. Additional population genetic and comparative genomic data are needed to elucidate the actual extent of host specificity in E. bieneusi and its potential impacts on zoonotic or interspecies transmission of microsporidiasis.
Topics: Animals; DNA, Ribosomal Spacer; Enterocytozoon; Genetic Variation; Genetics, Population; Genotype; Host Specificity; Humans; Microsporidiosis; Multilocus Sequence Typing; Phylogeny; Public Health Surveillance; Zoonoses
PubMed: 31494271
DOI: 10.1016/j.meegid.2019.104033 -
Current Opinion in Insect Science Apr 2018The common and widespread parasite Nosema ceranae is considered a major threat to the Western honey bee at both the individual and colony levels. Several studies... (Review)
Review
The common and widespread parasite Nosema ceranae is considered a major threat to the Western honey bee at both the individual and colony levels. Several studies demonstrated that infection by this parasite may affect physiology, behavior, and survival of honey bees. N. ceranae infection impairs midgut integrity and alters the energy demand in honey bees. The infection can also significantly suppress the bee immune response and modify pheromone production in worker and queen honey bees leading to precocious foraging. However, the presence of N. ceranae is not systematically associated with colony weakening and honey bee mortality. This variability depends upon parasite or host genetics, nutrition, climate or interactions with other stressors such as environmental contaminants or other parasites.
Topics: Animals; Bees; Behavior, Animal; Female; Microsporidiosis; Nosema
PubMed: 29764655
DOI: 10.1016/j.cois.2018.02.017 -
Rheumatology International Nov 2019Polymyositis is a diagnosis of exclusion. In patients with odd features, it can be of infective etiology. A high index of suspicion is required for diagnosis. A... (Review)
Review
Polymyositis is a diagnosis of exclusion. In patients with odd features, it can be of infective etiology. A high index of suspicion is required for diagnosis. A 55-year-old gentleman presented with gradual-onset proximal muscle weakness. Examination revealed mild distal weakness but no rash. Muscle enzymes were raised and tests for autoantibodies were negative. Biopsy revealed microsporidiosis. In view of this unusual infection, immunodeficiency was considered and he was found to have lymphopenia which antedated his illness. Later, he developed cranial nerve palsies due to multiple lesions in the pons. In addition, he had Cytomegalovirus viremia. Literature was reviewed to identify 20 cases of microsporidial myositis, its presentation, underlying immunodeficient state, and clinical course. Infective polymyositis should be considered in a patient with paucity of clinical and serological autoimmune features. Lymphopenia can point to underlying immunodeficiency. CMV infection could be the contributor to or bystander-effect of idiopathic lymphopenia.
Topics: Humans; Male; Microsporidiosis; Middle Aged; Myositis
PubMed: 31501996
DOI: 10.1007/s00296-019-04439-w -
Nature Microbiology Oct 2023
Topics: Microsporidia; Spores, Fungal; Microsporidiosis; Ribosomes
PubMed: 37709901
DOI: 10.1038/s41564-023-01481-0 -
Medical Mycology Apr 2023Microsporidia are fungi-related eukaryotic intracellular parasites that opportunistically infect immunocompromised individuals such as those infected by the human...
Microsporidia are fungi-related eukaryotic intracellular parasites that opportunistically infect immunocompromised individuals such as those infected by the human immunodeficiency virus (HIV). Among them, Enterocytozoon bieneusi and Encephalitozoon spp. are the most clinically relevant species. We investigated the occurrence and genetic diversity of microsporidial and protist infections in mostly immunocompetent HIV-positive patients in Madrid, Spain. A structured questionnaire was used to retrieve data on factors potentially associated with an increased risk of infection, including sexual attitudes and sex-risk behaviour. Faecal samples (n = 96) from 81 HIV-positive patients were collected and analysed by molecular (PCR and Sanger sequencing) methods. Two microsporidial pathogens were detected: Ent. bieneusi (2.5%, 95% CI: 0.3-8.6) and Enc.intestinalis (4.9%, 95% CI: 1.4-12.2). The two Ent. bieneusi isolates were identified as zoonotic genotype A. Among protists, Entamoeba dispar was the species most prevalently found (33.3%, 95% CI: 23.2-44.7), followed by Blastocystis spp. (19.8%, 95% CI: 11.7-30.1), Giardia duodenalis (13.6%, 95% CI: 7.0-23.0), and Cryptosporidium spp. and Entamoeba histolytica (2.5%, 95% CI: 0.3-8.6 each). Cyclospora cayetanensis and Cystoisospora belli were not detected. Subtypes ST1 (70.6%, 12/17) and ST3 (29.4%, 5/17) were identified within Blastocystis sp., sub-assemblages AII and BIII (50%, 1/2 each) within G. duodenalis, and Cry. parvum and canine-adapted Cry. canis (50%, 1/2 each) within Cryptosporidium spp. Microsporidial and protist parasites were frequent in well-controlled, mostly immunocompetent HIV-positive patients and should be included in diagnostic algorithms when diarrhoea is present.
Topics: Animals; Dogs; Humans; Cryptosporidiosis; Cryptosporidium; Encephalitozoon; Enterocytozoon; Feces; Genotype; HIV Infections; Microsporidia; Prevalence; Spain; Protozoan Infections; Microsporidiosis
PubMed: 37024274
DOI: 10.1093/mmy/myad039 -
Transactions of the Royal Society of... Sep 2017With the transformation of HIV infection from an acutely life-threatening disease into a chronic condition (as a consequence of the development of effective...
With the transformation of HIV infection from an acutely life-threatening disease into a chronic condition (as a consequence of the development of effective antiretroviral medication), the perceived clinical importance of diagnosing and treating microsporidian infections diminished, at least in industrialized countries. In locales where effective antiretroviral therapy is not available, as well as in patients with immunodeficiency for reasons other than HIV infection (e.g., following organ transplantation), and in individuals with suspected ocular microsporidiosis, diagnosing microsporidian infections remains a clinical priority. Molecular techniques can readily distinguish different species of microsporidia. At least one molecular diagnostic platform that can detect the intestinal parasites Encephalitozoon intestinalis and Enterocytozoon bieneusi is commercially available.
Topics: Humans; Microsporidia; Microsporidiosis; Molecular Diagnostic Techniques; Polymerase Chain Reaction
PubMed: 29244189
DOI: 10.1093/trstmh/trx070 -
Medical Mycology Sep 2022Microsporidia comprises a diverse group of obligate, intracellular, and spore-forming parasites that infect a wide range of animals. Among them, Enterocytozoon bieneusi...
Microsporidia comprises a diverse group of obligate, intracellular, and spore-forming parasites that infect a wide range of animals. Among them, Enterocytozoon bieneusi is the most frequently reported species in humans and other mammals and birds. Data on the epidemiology of E. bieneusi in wildlife are limited. Hence, E. bieneusi was investigated in eight wild ungulate species present in Spain (genera Ammotragus, Capra, Capreolus, Cervus, Dama, Ovis, Rupicapra, and Sus) by molecular methods. Faecal samples were collected from free-ranging (n = 1058) and farmed (n = 324) wild ungulates from five Spanish bioregions. The parasite was detected only in red deer (10.4%, 68/653) and wild boar (0.8%, 3/359). Enterocytozoon bieneusi infections were more common in farmed (19.4%, 63/324) than in wild (1.5%, 5/329) red deer. A total of 11 genotypes were identified in red deer, eight known (BEB6, BEB17, EbCar2, HLJD-V, MWC_d1, S5, Type IV, and Wildboar3) and three novel (DeerSpEb1, DeerSpEb2, and DeerSpEb3) genotypes. Mixed genotype infections were detected in 15.9% of farmed red deer. Two genotypes were identified in wild boar, a known (Wildboar3) and a novel (WildboarSpEb1) genotypes. All genotypes identified belonged to E. bieneusi zoonotic Groups 1 and 2. This study provides the most comprehensive epidemiological study of E. bieneusi in Spanish ungulates to date, representing the first evidence of the parasite in wild red deer populations worldwide. Spanish wild boars and red deer are reservoir of zoonotic genotypes of E. bieneusi and might play an underestimated role in the transmission of this microsporidian species to humans and other animals.
Topics: Animals; Animals, Wild; China; Deer; Enterocytozoon; Feces; Genotype; Humans; Microsporidiosis; Phylogeny; Prevalence; Sheep; Sheep Diseases; Spain; Sus scrofa; Swine; Swine Diseases
PubMed: 36095135
DOI: 10.1093/mmy/myac070