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Clinical Microbiology and Infection :... Feb 1995Human microsporidiosis is a parasitic infection due to species of four different genera: Encephalitozoon; Enterocytozoon; Nosema; and Pleistophora. Although well known...
Human microsporidiosis is a parasitic infection due to species of four different genera: Encephalitozoon; Enterocytozoon; Nosema; and Pleistophora. Although well known as a cause of disease in animals, microsporidiosis was only occasionally reported in humans. Recently, in human immunodeficiency virus (HIV)-infected patients, microsporidia belonging to Encephalitozoon and Enterocytozoon species have proved to be important opportunistic pathogens. Enterocytozoon bieneusi is associated with chronic intermittent diarrhea, cholangiopathy and sinusitis whereas Encephalitozoon intestinalis, Encephalitozoon hellem and Encephalitozoon cuniculi, the three Encephalitozoon species found in humans, are associated with diarrhea, rhinosinusitis, keratoconjunctivitis, nephritis and hepatitis. Diagnosis of microsporidial infections in humans was until recently an invasive, laborious procedure including electron microscopy of small intestine biopsies. However, new simple staining methods using Uvitex 2B or modified trichrome stain for feces and other body fluids have facilitated clinical diagnosis as well as drug evaluation and epidemiological studies. The application of monoclonal antibodies and molecular techniques such as the polymerase chain reaction have further improved microsporidial diagnosis. Treatment of Entero. bieneusi has, until now, been unsuccessful whereas albendazole has proved to be an effective treatment for Encephalitozoon species infection. Identification of effective treatment for Entero. bieneusi infections and further study of the pathogenicity of these microsporidial infections in immunocompetent hosts are important future challenges.
PubMed: 11866734
DOI: 10.1111/j.1469-0691.1995.tb00450.x -
Journal of Clinical Microbiology Nov 1994Microsporidia are primitive, spore-forming, mitochondria-lacking, eukaryotic protozoa that are obligate intracellular parasites. They are known to parasitize almost...
Polyclonal and monoclonal antibody and PCR-amplified small-subunit rRNA identification of a microsporidian, Encephalitozoon hellem, isolated from an AIDS patient with disseminated infection.
Microsporidia are primitive, spore-forming, mitochondria-lacking, eukaryotic protozoa that are obligate intracellular parasites. They are known to parasitize almost every group of animals including humans. Recently, microsporidia have increasingly been found to infect patients with AIDS. Five genera (Encephalitozoon, Enterocytozoon, Nosema, Septata, and Pleistophora) of microsporidia are known to infect humans. Enterocytozoon organisms cause gastrointestinal disease in a majority of AIDS patients with microsporidiosis. However, a smaller, but an expanding, number of patients with AIDS are being diagnosed with ocular and disseminated infection with Encephalitozoon hellem. Although microsporidial spores can be identified in clinical samples by a staining technique such as one with Weber's chromotrope stain, identification to the species level is dependent on cumbersome and time-consuming electron microscopy. We have recently isolated and established in continuous culture several strains of E. hellem from urine, bronchoalveolar lavage, and sputum samples from AIDS patients with disseminated microsporidiosis. We developed polyclonal and monoclonal antibodies and PCR primers to a strain of E. hellem that can be used successfully to identify E. hellem from other species of microsporidia either in clinical specimens or in cultures established from clinical specimens. Since patients infected with Encephalitozoon spp. are known to respond favorably to albendazole, identification of the parasite to the species level would be invaluable in the treatment of disseminated microsporidiosis.
Topics: Acquired Immunodeficiency Syndrome; Animals; Antibodies, Monoclonal; Antigens, Protozoan; Base Sequence; DNA, Protozoan; Encephalitozoon; Female; Humans; Immunoblotting; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Polymerase Chain Reaction; RNA, Ribosomal; Rabbits
PubMed: 7852569
DOI: 10.1128/jcm.32.11.2760-2768.1994 -
APMIS : Acta Pathologica,... Nov 1994Microsporidia are primitive mitochondria-lacking spore-forming eukaryotic protozoa that infect a wide variety of animals and also humans. Of the five genera...
Microsporidia are primitive mitochondria-lacking spore-forming eukaryotic protozoa that infect a wide variety of animals and also humans. Of the five genera (Encephalitozoon, Enterocytozoon, Septata, Nosema and Pleistophora) that cause infections in humans, Enterocytozoon bieneusi, Septata intestinalis, and Encephalitozoon hellem are being increasingly identified in patients with acquired immunodeficiency syndrome (AIDS). E. bieneusi causes gastrointestinal disease, S. intestinalis causes gastrointestinal and disseminated disease, and E. hellem causes ocular as well as disseminated disease. We have established in continuous culture a strain of microsporidia isolated from the urine and throat washings of an Italian AIDS patient and identified it as Encephalitozoon hellem, based on its ultrastructural morphology, antigenic pattern, and polymerase chain reaction-amplified small subunit ribosomal RNA. We believe that this is the first time that a strain of microsporidia has been isolated from the throat washings of a patient with microsporidiosis.
Topics: AIDS-Related Opportunistic Infections; Adult; Animals; Base Sequence; Cell Line; Chlorocebus aethiops; DNA Primers; Encephalitozoon; Encephalitozoonosis; Fluorescent Antibody Technique; Humans; Immunoblotting; Italy; Microscopy, Electron; Microscopy, Electron, Scanning; Molecular Sequence Data; Pharynx; RNA, Ribosomal; Vero Cells
PubMed: 7833001
DOI: No ID Found -
Clinical Microbiology Reviews Oct 1994Microsporidia are obligate intracellular spore-forming protozoal parasites belonging to the phylum Microspora. Their host range is extensive, including most... (Review)
Review
Microsporidia are obligate intracellular spore-forming protozoal parasites belonging to the phylum Microspora. Their host range is extensive, including most invertebrates and all classes of vertebrates. More than 100 microsporidial genera and almost 1,000 species have now been identified. Five genera (Enterocytozoon spp., Encephalitozoon spp., Septata spp., Pleistophora sp., and Nosema spp.) and unclassified microsporidia (referred to by the collective term Microsporidium) have been associated with human disease, which appears to manifest primarily in immunocompromised persons. The clinical manifestations of microsporidiosis are diverse and include intestinal, pulmonary, ocular, muscular, and renal disease. Among persons not infected with human immunodeficiency virus, ten cases of microsporidiosis have been documented. In human immunodeficiency virus-infected patients, on the other hand, over 400 cases of microsporidiosis have been identified, the majority attributed to Enterocytozoon bieneusi, an important cause of chronic diarrhea and wasting. Diagnosis of microsporidiosis currently depends on morphological demonstration of the organisms themselves. Initial detection of microsporidia by light microscopic examination of tissue sections and of more readily obtainable specimens such as stool, duodenal aspirates, urine, sputum, nasal discharge, bronchoalveolar lavage fluid, and conjunctival smears is now becoming routine practice. Definitive species identification is made by using the specific fluorescein-tagged antibody (immunofluorescence) technique or electron microscopy. Treatment options are limited, but symptomatic improvement of Enterocytozoon bieneusi infection may be achieved with the anthelmintic-antiprotozoal drug albendazole. Preliminary observations suggest that Septata intestinalis and Encephalitozoon infections may be cured with albendazole. Progress is being made with respect to in vitro propagation of microsporidia, which is crucial for developing antimicrosporidial drugs. Furthermore, molecular techniques are being developed for diagnostic purposes, taxonomic classification, and analysis of phylogenetic relationships of microsporidia.
Topics: Animals; HIV Infections; Humans; Microscopy, Electron; Microscopy, Electron, Scanning; Microsporida; Microsporidiosis
PubMed: 7834600
DOI: 10.1128/CMR.7.4.426 -
Clinical Infectious Diseases : An... Sep 1994Microsporidia are obligate, intracellular, spore-forming protozoal parasites. Their host range is extensive and includes most invertebrates and all classes of...
Microsporidia are obligate, intracellular, spore-forming protozoal parasites. Their host range is extensive and includes most invertebrates and all classes of vertebrates. Five microsporidial genera (Enterocytozoon, Encephalitozoon, Septata, Pleistophora, and Nosema) and unclassified microsporidia have been associated with human disease, which appears to manifest primarily in immunocompromised persons. The clinical manifestations of microsporidiosis are diverse and include intestinal, pulmonary, ocular, muscular, and renal disease. The majority of microsporidial infections in persons infected with human immunodeficiency virus (HIV) are attributed to Enterocytozoon bieneusi, an important cause of chronic diarrhea and wasting. Four cases of microsporidial infection among persons not infected with HIV who had documented or presumed cellular immunodeficiency and four cases of corneal stroma infection due to microsporidia in immunocompetent patients have been described. Furthermore, the first case of traveler's diarrhea due to E. bieneusi in an immunocompetent and otherwise healthy patient is reported in this issue. The sources of human microsporidial infections and modes of transmission are unknown.
Topics: Animals; HIV Infections; Humans; Immunocompetence; Immunocompromised Host; Microsporida; Protozoan Infections
PubMed: 7811872
DOI: 10.1093/clinids/19.3.517 -
The Journal of Eukaryotic Microbiology 1994In conclusion, at the current time the most important task of the laboratory for proper clinical management of the patient with microsporidiosis is to perform... (Review)
Review
In conclusion, at the current time the most important task of the laboratory for proper clinical management of the patient with microsporidiosis is to perform genus-level diagnosis of the agent, i.e. distinguishing Encephalitozoon sp. infection from other microsporidial agents including Septata, Enterocytozoon, Nosema, and Pleistophora. This can be performed in any well-equipped pathology department with access to electron microscopy. If species identification is desired, we currently recommend consultation with one of several laboratories specializing in this area until diagnostic reagents become more widely available.
Topics: AIDS-Related Opportunistic Infections; Encephalitozoonosis; Eye Infections, Parasitic; Female; Humans; Male; Prostatitis; Respiratory Tract Infections; Urinary Tract Infections
PubMed: 7804259
DOI: No ID Found -
Folia Parasitologica 1994Microsporidiosis is an increasingly important opportunistic infection in HIV-positive patients. Five species of microsporidia (Enterocytozoon bieneusi, Encephalitozoon... (Review)
Review
Microsporidiosis is an increasingly important opportunistic infection in HIV-positive patients. Five species of microsporidia (Enterocytozoon bieneusi, Encephalitozoon hellem and E. cuniculi, Septata intestinalis, and Pleistophora sp.) have been reported to occur in AIDS, with each agent producing a different clinicopathologic spectrum of disease. This communication reviews routine and specialized methods for diagnosis of these important pathogenic protozoa, including biopsy, cytology, ultrastructural and immunologic examination, and tissue culture, and describes the current knowledge of organ distribution for microsporidia in persons with AIDS.
Topics: AIDS-Related Opportunistic Infections; Animals; Biopsy; Culture Techniques; Cytological Techniques; Humans; Microscopy, Electron; Microsporida; Microsporidiosis; Serologic Tests
PubMed: 7927059
DOI: No ID Found -
Przeglad Epidemiologiczny 1994The list of infections, threatening patients with impaired immunological system, especially infected with HIV, prolongs systematically. Since early eighties many authors... (Review)
Review
The list of infections, threatening patients with impaired immunological system, especially infected with HIV, prolongs systematically. Since early eighties many authors pay attention to little known type of protozoan: Microspora. More and more often new microsporidia species are described as a cause of disease, especially in patients with AIDS. We present review of literature data concerning species known up to now as pathogenic for man: Encephalitozoon cuniculi, Encephalitozoon hellem, Nosema connori and Nosema corneum, Pleistophora sp., as well as enteropathogenic for AIDS-patients-Enterocytozoon bieneusi and Septata intestinalis.
Topics: Animals; HIV Seropositivity; Humans; Microsporida; Microsporidiosis
PubMed: 7597182
DOI: No ID Found -
Archives of Pathology & Laboratory... Dec 1993The obligate intracellular protozoan parasites belonging to the phylum Microspora are ubiquitous. They parasitize insects and all five classes of vertebrates. Only one... (Comparative Study)
Comparative Study Review
The obligate intracellular protozoan parasites belonging to the phylum Microspora are ubiquitous. They parasitize insects and all five classes of vertebrates. Only one genus infects mammals and birds but at least four genera affect humans. Two genera have been isolated from human specimens and both infect experimental animals. Some genera (eg, Enterocytozoon and Pleistophora) seem to be limited to a very few tissues but others (Encephalitozoon and the Encephalitozoon-like genus Septata) can infect multiple organs. Lesions range from classic microgranulomas to foci of infected cells unaccompanied by any inflammatory response. The most commonly occurring microsporidia infection of man (Enterocytozoon bieneusi) is characterized by infection of enterocytes of the villus tips of the small intestine, accompanied by villus blunting, crypt hyperplasia, sloughing of infected villus tip cells, and increased numbers of intraepithelial lymphocytes.
Topics: Animals; Humans; Microsporida; Microsporidiosis
PubMed: 8250691
DOI: No ID Found -
Clinical Microbiology Reviews Jan 1993Nine cases of unusual infections in humans are presented. In each case, we present the clinical history, histopathologic changes (if indicated), morphologic features of... (Review)
Review
Nine cases of unusual infections in humans are presented. In each case, we present the clinical history, histopathologic changes (if indicated), morphologic features of the causative organism, diagnosis, discussion, differential diagnosis, therapy, and current literature. All of the cases are illustrated with pertinent photographs. The nine cases are as follows: (i) acanthocephaliasis, the first acquired human infection by Moniliformis moniliformis in the United States; (ii) dipylidiasis, an uncommon infection caused by the dog tapeworm, Dipylidium caninum; (iii) granulomatous amebic encephalitis, caused by the recently identified leptomyxid group of amebae; (iv) schistosomiasis, a dual infection of the urinary bladder with the rare presentation of both adult worms and eggs of Schistosoma haematobium and Schistosoma mansoni in tissue sections; (v) syphilitic gastritis, an uncommon presentation of Treponema pallidum infection, in a patient with an additional incidental infection by Helicobacter pylori; (vi) microsporidiosis, the only infection caused by a Pleistophora sp. in humans; (vii) sporotrichosis, a rare disseminated infection caused by Sporothrix schenckii with numerous yeast cells in the scrotum; (viii) angiostrongyliasis, the first and only infection caused by Angiostrongylus costaricensis acquired in either Puerto Rico or the United States; and (ix) botryomycosis of the skin and subcutaneous tissue, caused by gram-positive cocci with an unusually large number of granules.
Topics: Adult; Aged; Amebiasis; Bacterial Infections; Cestode Infections; Diagnosis, Differential; Female; Helminthiasis; Humans; Infant; Male; Middle Aged; Protozoan Infections; Schistosomiasis; Sporotrichosis; Syphilis
PubMed: 8457979
DOI: 10.1128/CMR.6.1.34