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fine structure of a new human microsporidian, encephalitozoon hellem, in culture.encephalitozoon hellem is a new human microsporidian isolated from corneal biopsies and conjunctival scrapings of three aids patients and cultured in madin darby canine kidney (mdck) cells. encephalitozoon hellem and encephalitozoon cuniculi display different protein profiles with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and unique antibody binding patterns with murine antisera against western blots of each organism. developmental stages of e. hellem in culture are similar to e. ...19911920150
isolation and characterization of a new human microsporidian, encephalitozoon hellem (n. sp.), from three aids patients with keratoconjunctivitis.a new human microsporidian was isolated from cultures of madin-darby canine kidney cells incubated with conjunctival scrapings or corneal tissues from three aids patients with keratoconjunctivitis. the three isolates were morphologically similar to encephalitozoon cuniculi. the spores averaged 1 x 1.5-2.0 microns, had six to eight polar filament coils, displayed monokaryotic nuclei, and possessed relatively thick endospores with irregularly shaped exospores. organisms developed within a parasito ...19911995733
human microsporidiosis. 19902121831
prevalence of antibodies to encephalitozoon cuniculi in stray dogs as determined by an elisa.an elisa, using encephalitozoon cuniculi spores as antigen, was used to determine the prevalence of specific anti-e cuniculi igg in a group of stray dogs. in a preliminary survey 51 of 248 sera were classified as positive with titres of 1:400 to 1:3200. the 18 sera with titres of 1:400 were reclassified as negative when no igg binding to the spores could be detected by comparison with a standard curve of anti-e cuniculi igg. the remaining 33 sera (13.3 per cent) were classified as low, moderate ...19892497576
human microsporidiosis and aids.several protozoan parasites of the phylum microspora, previously only rarely recognized in humans, are being detected with increasing frequency in patients with aids. these protozoa are small obligate intracellular parasites of the intestine, liver, muscles, cornea, and several other tissues. they are difficult to detect because they stain poorly, often evoke little or no tissue response, and require electron-microscopic methods for classification. although there are no human isolates, serologic ...19892649958
detection of microsporidia (enterocytozoon bieneusi) in intestinal biopsy specimens from human immunodeficiency virus-infected patients by pcr.intestinal microsporidiosis has been implicated as a major cause of chronic diarrhea in human immunodeficiency virus (hiv)-infected patients. so far diagnosis depends on direct visualization of the parasites by light and transmission electron microscopy. we evaluated the diagnostic value of microsporidian dna amplification by pcr on duodenal biopsy specimens obtained from patients with and without intestinal microsporidiosis caused by enterocytozoon bieneusi. thirteen hiv-infected patients (all ...19957494017
genetic and immunological characterization of the microsporidian septata intestinalis cali, kotler and orenstein, 1993: reclassification to encephalitozoon intestinalis.the relationships between the encephalitozoon-like septata intestinalis and other microsporidia that occur in humans; notably encephalitozoon cuniculi and encephalitozoon hellem, is insufficiently documented using morphological descriptions alone. to assess mutual relationships, we have examined other phenotypic as well as genetic aspects of s. intestinalis, obtained both from tissue culture and clinical specimens, in comparison with a number of other microsporidia. phenotypic characterization w ...19957724235
detection of microsporidia by indirect immunofluorescence antibody test using polyclonal and monoclonal antibodies.during a screening for monoclonal antibodies (mabs) to the microsporidian encephalitozoon hellem, three murine hybridoma cell lines producing strong enzyme-linked immunosorbent assay (elisa) reactivities were cloned twice, were designated c12, e9, and e11, and were found to secrete mabs to the immunoglobulin m isotype. on subsequent elisas, the three mabs reacted most strongly to e. hellem, and they reacted somewhat less to encephalitozoon cuniculi and least to nosema corneum, two other microspo ...19948195366
purification and characterization of human microsporidian polar tube proteins. 19968822888
identification of microsporidia causing human disease. 19968822891
immunologic and molecular characteristics of encephalitozoon-like microsporidia isolated from humans and rabbits indicate that encephalitozoon cuniculi is a zoonotic parasite.to assess the zoonotic potential of encephalitozoon-like microsporidia, we isolated and cultivated spores from specimens of urine, respiratory secretions, and stool from six patients infected with human immunodeficiency virus and from nine rabbits. because spores of encephalitozoon-like species are indistinguishable by microscopy, we characterized the isolates by western blot analysis and by restriction enzyme analysis of the small subunit (ssu) rdna after amplification by the polymerase chain r ...19968852978
two encephalitozoon cuniculi strains of human origin are infectious to rabbits.the microsporidian encephalitozoon cuniculi can infect a wide variety of mammals including man. in this study, e. cuniculi isolates of animal origin were compared with 6 isolates obtained from hiv-infected patients. based on results of western blot analysis, random amplified polymorphic dna (rapd) and the sequence of the rdna internal transcribed spacer (its) the isolates were classified into 3 groups with the repeated element 5'gttt-3' in the its being a reliable genetic marker. five isolates f ...19979011071
western blot and immunofluorescence analysis of a human isolate of encephalitozoon cuniculi established in culture from the urine of a patient with aids.microsporidia spores, identified as encephalitozoon cuniculi (cdc: v282), were isolated from the urine of a patient with acquired immunodeficiency syndrome and disseminated microsporidiosis, established in continuous culture on monkey kidney cells (e6), and antiserum was produced in rabbits. immunoblot studies that used the patient serum and the rabbit sera against cdc:v282, encephalitozoon hellem (cdc:0291:v213), and encephalitozoon intestinalis (cdc:v297) revealed that cdc:v282 and the rabbit ...19979057698
species-specific identification of microsporidia in stool and intestinal biopsy specimens by the polymerase chain reaction.in view of the increasing number of cases of human microsporidiosis, simple and rapid methods for clear identification of microsporidian parasites to the species level are required. in the present study, the polymerase chain reaction (pcr) was used for species-specific detection of encephalitozoon cuniculi. encephalitozoon hellem, encephalitozoon (septata) intestinalis, and enterocytozoon bieneusi in both tissue and stool. using stool specimens and intestinal biopsies of patients infected with e ...19979228477
bovine leukemia virus-induced clinical signs and morphological changes of encephalitozoonosis in rabbits.fourteen three-month-old rabbits spontaneously-infected with the microsporidium encephalitozoon cuniculi levaditi, nicolau et schoen, 1923 were inoculated intravenously with lymphocytes (ly) from seropositive bovine leukemia virus infected cattle (ly/blv) or with fetal lamb kidney cells infected with bovine fetal leukemia (flk/blv). thirteen rabbits were seropositive to blv at least for a period of three months. six rabbits died of pulmonary lesions. chronic inflammatory lesions of encephalitozo ...19979437837
animal models of human microsporidial infections.two new models have been described for enterocytozoon bieneusi, non-human primates and immuno-suppressed gnotobiotic pigs, but there still is no successful cell culture system. the intestinal xenograft system holds promise as an animal model for encephalitozoon intestinalis. encephalitozoon hellem is easily propagated in mice, and also may be an important cause of spontaneous disease of psittacine birds. encephalitozoon cuniculi occurs spontaneously in a wide variety of animals and can be induce ...199810090081
rabbit intestinal xenograft model for human encephalitozoon infections in mice.the gastrointestinal tract is a common portal of entry for encephalitozoon cuniculi, one of several microsporidial organisms emerging as opportunistic pathogens in immunocompromised humans. although most human microsporidial pathogens can be propagated in vitro and in a variety of laboratory animals, an experimental animal system to specifically study intestinal uptake and systemic spread of these organisms does not exist.199910331549
strain differentiation in microsporidia.microsporidia are obligate intracellular, spore-forming protozoa and are regarded as newly emerging pathogens . enterocytozoon spp. as well as encephalitozoon spp. are recognized as major aetiological agents in chronic diarrhoea of immnunocompromised patients. the detection and differentiation of strains within microsporidial species is a prerequisite for the elucidation of their hitherto unknown reservoirs and their mode of transmission . in enterocytozoon bieneusi, the most prevalent human-pat ...199810622643
phagocytic uptake of encephalitozoon cuniculi by nonprofessional phagocytes.encephalitozoon cuniculi is an obligate intracellular, spore-forming parasite belonging to the microsporidia that can cause disseminated infection in immunocompromised persons. e. cuniculi spores infect host cells by germination, i.e., by explosively everting the polar filament, through which the spore contents (sporoplasms) are subsequently injected into the cytoplasm. in addition, we observed intracellular, nongerminated spores in various nonprofessional phagocytes. in mrc5 cells, the number o ...200011083817
the microsporidian encephalitozoon.encephalitozoon cuniculi is an attractive model system for amitochondriate intracellular eukaryotic parasites. it is characterized by a very small genome (below 3 mbp) and a unique invasion apparatus. furthermore, as an infectious agent, it is important in human and veterinary medicine. the compactness of its genome involves the reduction of rdna sequences as well as of some protein-coding genes and intergenic regions. its highly differentiated apparatus to penetrate the host cell, an extrusome- ...200111169593
[microsporidiosis].opportunistic parasites: microsporidia are primitive eukaryotic parasites widespread in a large range of animal species. these opportunistic parasites can cause infections in humans, mainly in immunocompromised patients. pathogenic species: four microsporidian species are important in human pathology, enterocytozoon bieneusi, encephalitozoon intestinalis, encephalitozoon cuniculi and encephalitozoon hellem. laboratory diagnosis: a difficult task, laboratory diagnosis is based on direct microscop ...200111225488
dual microsporidial infection with encephalitozoon cuniculi and enterocytozoon bieneusi in an hiv-positive patient.this report describes the first dual microsporidial infection with encephalitozoon cuniculi and enterocytozoon bieneusi in an hiv-positive patient. in view of clinical and epidemiological findings, our e. cuniculi isolate was deduced to be of the dog strain. the patient's occupational involvement with dogs indicates that canines should be considered as a reservoir of human infections for both microsporidial species. furthermore, our report provides detailed clinical and radiological information ...200111545489
in vitro activity of polyoxin d and nikkomycin z against encephalitozoon cuniculi.microsporidia of the genus encephalitozoon are emerging protozoal agents that mainly infect immunocompromised patients with aids. at present, disseminated infections with members of the genus encephalitozoon can only be successfully treated with albendazole. as chitin is a basic component of the microsporidian spore. we evaluated, in vitro, the susceptibility of a human-derived strain of encephalitozoon cuniculi to polyoxin d and nikkomycin z, which are known competitive inhibitors of chitin syn ...200212049463
first isolation and characterisation of encephalitozoon cuniculi from a free-ranging rat (rattus norvegicus).the microsporidian species encephalitozoon cuniculi can infect a wide variety of mammals including man. it is a common parasite in rabbits and several sporadic infections in laboratory rats have been described. based on molecular data three e. cuniculi strains have been identified. here we describe the first in vitro propagation of e. cuniculi, which was isolated from a free-ranging rat (rattus norvegicus). the rat was one of three seropositive animals among 23 rats captured in the city of zuric ...200212163239
serological investigation of canine encephalitozoonosis in norway.encephalitozoon cuniculi, a microsporidian parasite of vertebrates, is considered a health risk to aids patients and other immunocompromised human beings. in most hosts, infection with the parasite runs a subclinical course. in some carnivore species, however, clinical disease affecting whole litters arises from intrauterine transmission of the parasite. in both blue foxes ( alopex lagpus) and dogs ( canis familiaris), outbreaks of encephalitozoonosis can be severe. canine encephalitooonosis has ...200312474043
the cog database: an updated version includes eukaryotes.the availability of multiple, essentially complete genome sequences of prokaryotes and eukaryotes spurred both the demand and the opportunity for the construction of an evolutionary classification of genes from these genomes. such a classification system based on orthologous relationships between genes appears to be a natural framework for comparative genomics and should facilitate both functional annotation of genomes and large-scale evolutionary studies.200312969510
strand compositional asymmetries of nuclear dna in eukaryotes.both dna replication and transcription are structurally asymmetric processes. an asymmetric nucleotide substitution pattern has been observed between the leading and the lagging strand, and between the coding and the noncoding strand, in eubacterial, viral, and organelle genomes. similar studies in eukaryotes have been rare, because the origins of replication in nuclear genomes are mostly unknown and the replicons are much shorter than those of prokaryotes. to circumvent these predicaments, all ...200314629042
a comprehensive evolutionary classification of proteins encoded in complete eukaryotic genomes.sequencing the genomes of multiple, taxonomically diverse eukaryotes enables in-depth comparative-genomic analysis which is expected to help in reconstructing ancestral eukaryotic genomes and major events in eukaryotic evolution and in making functional predictions for currently uncharacterized conserved genes.200414759257
polyamine metabolism in a member of the phylum microspora (encephalitozoon cuniculi): effects of polyamine analogues.the uptake, biosynthesis and catabolism of polyamines in the microsporidian parasite encephalitozoon cuniculi are detailed with reference to the effects of oligoamine and arylamine analogues of polyamines. enc. cuniculi, an intracellular parasite of mammalian cells, has both biosynthetic and catabolic enzymes of polyamine metabolism, as demonstrated in cell-free extracts of mature spores. the uptake of polyamines was measured in immature, pre-emergent spores isolated from host cells by percoll g ...200415133083
comparative analysis of complete genomes reveals gene loss, acquisition and acceleration of evolutionary rates in metazoa, suggests a prevalence of evolution via gene acquisition and indicates that the evolutionary rates in animals tend to be conserved.in this study we systematically examined the differences between the proteomes of metazoa and other eukaryotes. metazoans (homo sapiens, ceanorhabditis elegans and drosophila melanogaster) were compared with a plant (arabidopsis thaliana), fungi (saccharomyces cerevisiae and schizosaccaromyces pombe) and encephalitozoan cuniculi. we identified 159 gene families that were probably lost in the metazoan branch and 1263 orthologous families that were specific to metazoa and were likely to have origi ...200415448184
fatal pulmonary microsporidiosis due to encephalitozoon cuniculi following allogeneic bone marrow transplantation for acute myelogenous leukemia.microsporidia are ubiquitous obligate eukaryotic intracellular parasites that are now felt to be more akin to degenerate fungi than to protozoa. microsporidia can be highly pathogenic, causing a broad range of symptoms in humans, especially individuals who are immunocompromised. the vast majority of human cases of microsporidiosis have been reported during the past 20 years, in patients with hiv/aids, while only relatively rare cases have been described in immunocompetent individuals. however, m ...200516036880
activity of bleach, ethanol and two commercial disinfectants against spores of encephalitozoon cuniculi.encephalitozoon cuniculi is a small protist parasite in the phylum microspora. hosts are infected by ingestion or inhalation of spores passed in the urine or feces. infection with e. cuniculi is usually asymptomatic, except in young or immunocompromised hosts. this study examined the effects of various disinfectants on in vitro infectivity of e. cuniculi spores. spores of e. cuniculi were exposed to several dilutions of commercial bleach, 70% ethanol and dilutions of commercial disinfectants hit ...200616368193
genetic structure and evolution of the vps25 family, a yeast escrt-ii component.vps25p is the product of yeast gene vps25 and is found in an endosomal sorting complex required for transport (escrt)-ii, along with vps22p and vps36p. this complex is essential for sorting of ubiquitinated biosynthetic and endosomal cargoes into endosomes.200616889659
comparative analysis of trichomonad genome sizes and karyotypes.in parasitic protists, the genome sizes range from 2.9mb in encephalitozoon cuniculi to about 160mb in trichomonas vaginalis. the suprisingly large genome size of the former human parasite resulted from the expansion of various repetitive elements, specific gene families, and possibly from large-scale genome duplication. the reason for this phenomenon, as well as whether other trichomonad species have undergone a similar genome expansion, is not known. in this work we studied the genomes of nine ...200818606195
frequent occurrence of human-associated microsporidia in fecal droppings of urban pigeons in amsterdam, the netherlands.human-associated microsporidia were frequently observed in fecal samples of 331 feral pigeons in amsterdam, the netherlands, obtained during high- and low-breeding periods. thirty-six of 331 samples (11%) contained the human pathogens enterocytozoon bieneusi (n = 18), encephalitozoon hellem (n = 11), encephalitozoon cuniculi (n = 6), and encephalitozoon intestinalis (n = 1); 5 samples contained other microsporidia. pigeon feces can be an important source of human microsporidian infection.200818805997
structural and functional characterization of a putative polysaccharide deacetylase of the human parasite encephalitozoon cuniculi.the microsporidian encephalitozoon cuniculi is an intracellular eukaryotic parasite considered to be an emerging opportunistic human pathogen. the infectious stage of this parasite is a unicellular spore that is surrounded by a chitin containing endospore layer and an external proteinaceous exospore. a putative chitin deacetylase (ecu11_0510) localizes to the interface between the plasma membrane and the endospore. chitin deacetylases are family 4 carbohydrate esterases in the cazy classificatio ...200919472335
purified ptp1 protein induces antigen-specific protective immunity against encephalitozoon cuniculi.microsporidiosis poses a problem for immunocompromised individuals including patients with hiv infection as well as those with organ transplantation. recent reports from africa have suggested that microsporidiosis with diarrhea is an independent risk factor for malnutrition in children. previous studies from our laboratory have demonstrated that cd8(+) t cells are an essential component of protective immunity against the microsporidium encephalitozoon cuniculi. mutant mice lacking this t cell su ...201020348007
the varying microsporidian genome: existence of long-terminal repeat retrotransposon in domesticated silkworm parasite nosema bombycis.microsporidia are a group of intracellular parasites with an extremely compact genome and there is no confirmed evidence that retroelements are parasitised in these organisms. using the dataset of 200,000 genomic shotgun reads of the silkworm pebrine nosema bombycis, we have identified the eight complete n. bombycis long-terminal repeat retrotransposon (nbr) elements. all of the nbr elements are ty3/gypsy members and have close relationships to saccharomycetes long-terminal repeat retrotransposo ...200616797019
staining of microsporidian spores by optical brighteners with remarks on the use of brighteners for the diagnosis of aids associated human microsporidioses.conditions for the effective fluorescence labelling of microsporidian spores by optical brighteners, based on the presence of chitin in the spore wall, are described. spores of vairimorpha ephestiae, v. necatrix, v. plodiae, nosema bombycis, n. apis, n. algerae, encephalitozoon cuniculi and enterocytozoon bieneusi were examined. the degree of binding of calcofluor white m2r (cfw) to untreated spores depends on the conditions and time of storage and the degree of bacterial contamination of the sp ...19937516908
isolation of encephalitozoon cuniculi from urine samples.encephalitozoon cuniculi was isolated from the urine of infected rabbits using human and canine tissue cultures. the organism was isolated from 7 of 11 contaminated urines from seropositive animals. the advantages of urine over tissue as a source of e. cuniculi are that it is obtainable from living animals, can be examined for the presence of organisms, and is essentially free of cells likely to overgrow the tissue cultures used for isolation.1977926750
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