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Journal of Clinical Microbiology Nov 1996Microsporidia are zoonotic protozoa which were rare human pathogens prior to 1985, when Enterocytozoon bieneusi was described in human immunodeficiency virus-infected...
Microsporidia are zoonotic protozoa which were rare human pathogens prior to 1985, when Enterocytozoon bieneusi was described in human immunodeficiency virus-infected patients with chronic diarrhea. Another species, Encephalitozoon (Septata) intestinalis, is associated with diarrhea and chronic sinusitis, and approximately 25 cases have been reported in the literature. However, other microsporidial infections in human immunodeficiency virus-infected patients remain extremely rare. We report the first case of a Pleistophora sp.-like microsporidian infection presenting as a progressive severe myosotis associated with fever and weight loss. The organism was demonstrated by light microscopy and electron microscopy in corneal scrapings, skeletal muscle, and nasal discharge. Electron microscopy showed an electron-dense surface coat with "sunflare"-like projections surrounding all stages of development of meronts (two to four nuclei, dividing by binary fission), sporonts, and sporoblasts. Division of sporonts, in which sporonts separate from the thick outer coat, creating a sporophorous vesicle, is by binary fission, differentiating this organism from Pleistophora sp. The spore measures 4.0 by 2.5 microns and has a rugose exospore. A new genus and species, Trachipleistophora hominis, has been established for this parasite. The patient was treated with albendazole, sulfadiazine, and pyrimethamine, and the clinical symptoms resolved.
Topics: AIDS-Related Opportunistic Infections; Adult; Albendazole; Animals; Anti-Infective Agents; Drug Therapy, Combination; Humans; Male; Microscopy, Electron; Microsporida; Microsporidiosis; Myositis; Pyrimethamine; Sulfadiazine
PubMed: 8897186
DOI: 10.1128/jcm.34.11.2803-2811.1996 -
Current Opinion in Infectious Diseases Oct 1999Sources of human microsporidial infection remain speculative, but possible animal reservoirs are emerging. Of the common human microsporidial infections, Enterocytozoon...
Sources of human microsporidial infection remain speculative, but possible animal reservoirs are emerging. Of the common human microsporidial infections, Enterocytozoon bieneusi has now been identified in non-human primates, pigs, dogs and a cat; Encephalitozoon intestinalis in dogs, pigs, cows, goats and donkeys and Encephalitozoon hellem in budgerigars and parrots. Evidence of species heterogeneity is also emerging suggesting that some animal isolates may be distinctive. Further molecular epidemiological studies need to be undertaken to clarify which animal genotypes can also infect humans. Some of the less common microsporidial infections found in humans, such as those involving Pleistophora-like species, may be the result of infrequent accidental exposure (for example, inadequately cooked infected fish muscle) and establishment, particularly if the individual is severely immunocompromised.
PubMed: 17035814
DOI: 10.1097/00001432-199910000-00010 -
Parasitology Research Jan 2011Out of 600 marine fish from the Red Sea belonging to three different species that were collected and examined for microsporidian parasites, 87 (14.5%) fish were found to...
Out of 600 marine fish from the Red Sea belonging to three different species that were collected and examined for microsporidian parasites, 87 (14.5%) fish were found to be infected. The infection was recorded as cysts or xenomas embedded in the gut epithelium and the peritoneal cavity of the three fish species. The highest percent of infection with microsporidian parasites was recorded in Saurida tumbil 19.5% (39/200) followed by Pagrus pagrus 15% (45/300) and the lowest percent of infection was recorded in Epinephelus chlorostigma 3% (three out of 100). After rupture of the cysts, the spores were released and examined by light microscopy. Each spore was elongated to ellipsoidal in shape and possessed a posterior vacuole which is characteristic to phylum Microspora. They measure 1.6 ± 0.5 μm (1.5-2.4 μm) × 1.3 ± 0.1 μm (1.3-2.0 μm) in Saurida tumbil and Pagrus pagrus, respectively. The spores of Pleistophora sp recorded from E. chlorostigma were ovoid to pyriform in shape and measure 1.9 ± 0.5 μm (1.8-2.7 μm) × 1.6 ± 0.4 μm (1.5-2.4 μm).
Topics: Animals; Fish Diseases; Fishes; Histocytochemistry; Indian Ocean; Intestinal Mucosa; Microscopy; Microsporidia; Microsporidiosis; Peritoneal Cavity; Prevalence
PubMed: 20865429
DOI: 10.1007/s00436-010-2061-1 -
The Journal of Animal Ecology Mar 2015Predatory functional responses play integral roles in predator-prey dynamics, and their assessment promises greater understanding and prediction of the predatory impacts...
Predatory functional responses play integral roles in predator-prey dynamics, and their assessment promises greater understanding and prediction of the predatory impacts of invasive species. Other interspecific interactions, however, such as parasitism and higher-order predation, have the potential to modify predator-prey interactions and thus the predictive capability of the comparative functional response approach. We used a four-species community module (higher-order predator; focal native or invasive predators; parasites of focal predators; native prey) to compare the predatory functional responses of native Gammarus duebeni celticus and invasive Gammarus pulex amphipods towards three invertebrate prey species (Asellus aquaticus, Simulium spp., Baetis rhodani), thus, quantifying the context dependencies of parasitism and a higher-order fish predator on these functional responses. Our functional response experiments demonstrated that the invasive amphipod had a higher predatory impact (lower handling time) on two of three prey species, which reflects patterns of impact observed in the field. The community module also revealed that parasitism had context-dependent influences, for one prey species, with the potential to further reduce the predatory impact of the invasive amphipod or increase the predatory impact of the native amphipod in the presence of a higher-order fish predator. Partial consumption of prey was similar for both predators and occurred increasingly in the order A. aquaticus, Simulium spp. and B. rhodani. This was associated with increasing prey densities, but showed no context dependencies with parasitism or higher-order fish predator. This study supports the applicability of comparative functional responses as a tool to predict and assess invasive species impacts incorporating multiple context dependencies.
Topics: Acanthocephala; Amphipoda; Animals; Chironomidae; Ephemeroptera; Food Chain; Introduced Species; Isopoda; Pleistophora; Population Dynamics; Predatory Behavior; Trout
PubMed: 25265905
DOI: 10.1111/1365-2656.12292 -
Parassitologia Dec 1991Parasites of the phylum Microspora are obligatory intracellular protoza with a widespread host range among invertebrates and vertebrates. Species from Nosema,... (Review)
Review
Parasites of the phylum Microspora are obligatory intracellular protoza with a widespread host range among invertebrates and vertebrates. Species from Nosema, Encephalitozoon, Enterocytozoon and Pleistophora genera can infect immunocompetent and immunosuppressed patients. The emergency of the AIDS epidemic has recently highlighted the role of these parasites in human pathology, microsporidian species being a frequent cause of diarrhoea and ocular infections. Recent acquisitions in the taxonomy and life cycle of this parasite group, as well as pathogenesis, immunopathology, clinical aspects, diagnosis, therapy and epidemiology of human microsporidiosis are reviewed and discussed.
Topics: AIDS-Related Opportunistic Infections; Animals; Disease Susceptibility; Humans; Immunocompetence; Immunocompromised Host; Microsporida; Microsporidiosis
PubMed: 1844514
DOI: No ID Found -
Revista Latinoamericana de Microbiologia 1996Protozoa of the order Microsporida have become regarded as causes of several pathologies in patients with severe immunodeficiencies. Apparently they are transmitted to... (Review)
Review
Protozoa of the order Microsporida have become regarded as causes of several pathologies in patients with severe immunodeficiencies. Apparently they are transmitted to the human through fecalism, but also the respiratory route has been considered. People most affected are young males infected with the human immunodeficiency virus. The most important genera are: Enterocytozoon, Encephalitozoon, Septata, Nosema and Pleistophora. There are discrepancies about the biology of these parasites and little is known of their behavior in the human host. It is concluded that with the advent of AIDS, many nosological entities by opportunistic organisms, that were not previously considered as human infections are appearing. This work is a review of the literature published from 1959 to 1995, related to epidemiological, clinical, diagnostic and therapeutic aspects.
Topics: AIDS-Related Opportunistic Infections; Animals; Antiprotozoal Agents; Comorbidity; Diarrhea; Female; Herpesviridae Infections; Humans; Intestinal Diseases, Parasitic; Male; Microsporida; Microsporidiosis; Mycoses
PubMed: 9026860
DOI: No ID Found -
Royal Society Open Science Mar 2015Cannibalism is ubiquitous in nature and especially pervasive in consumers with stage-specific resource utilization in resource-limited environments. Cannibalism is thus...
Cannibalism is ubiquitous in nature and especially pervasive in consumers with stage-specific resource utilization in resource-limited environments. Cannibalism is thus influential in the structure and functioning of biological communities. Parasites are also pervasive in nature and, we hypothesize, might affect cannibalism since infection can alter host foraging behaviour. We investigated the effects of a common parasite, the microsporidian Pleistophora mulleri, on the cannibalism rate of its host, the freshwater amphipod Gammarus duebeni celticus. Parasitic infection increased the rate of cannibalism by adults towards uninfected juvenile conspecifics, as measured by adult functional responses, that is, the rate of resource uptake as a function of resource density. This may reflect the increased metabolic requirements of the host as driven by the parasite. Furthermore, when presented with a choice, uninfected adults preferred to cannibalize uninfected rather than infected juvenile conspecifics, probably reflecting selection pressure to avoid the risk of parasite acquisition. By contrast, infected adults were indiscriminate with respect to infection status of their victims, probably owing to metabolic costs of infection and the lack of risk as the cannibals were already infected. Thus parasitism, by enhancing cannibalism rates, may have previously unrecognized effects on stage structure and population dynamics for cannibalistic species and may also act as a selective pressure leading to changes in resource use.
PubMed: 26064614
DOI: 10.1098/rsos.140369 -
The Journal of Eukaryotic Microbiology 1998Ribosomal DNA from eight species of microsporidians infecting fish have been sequenced. Seven of these species infect the skeletal muscle of fish (Pleistophora spp.) and...
Ribosomal DNA from eight species of microsporidians infecting fish have been sequenced. Seven of these species infect the skeletal muscle of fish (Pleistophora spp.) and one species infects migratory mesenchyma cells (Glugea anomala). These sequences, in addition to other available microsporidian rDNA sequences from a broad range of host taxa, have been used in phylogenetic analysis. This analysis revealed that muscle-infecting microsporidians from fish are a polyphyletic group, indicating that characters supposed to be important in the classification of the genus Pleistophora have to be re-evaluated. One character that probably has a polyphyletic origin is the amorphous coat, which has been extensively used in the definition of this genus. Furthermore, our results showed that the insect parasitizing Pleistophora spp. are not related to the true pleistophorans parasitic in skeletal muscle of fish. Phylogenetic analysis of small subunit rDNA sequences revealed disagreements between the molecular phylogeny and classifications based upon ultrastructure. Many of the morphological characters claimed to be important in microsporidian classifications appeared to have arisen several times during evolution: for example, the diplokaryon and sporophorous vesicles.
Topics: Animals; Cloning, Molecular; DNA, Protozoan; DNA, Ribosomal; Evolution, Molecular; Fishes; Microsporida; Muscle, Skeletal; Phylogeny; Polymerase Chain Reaction; RNA, Protozoan; RNA, Ribosomal
PubMed: 9783455
DOI: 10.1111/j.1550-7408.1998.tb05113.x -
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 -
Journal of Comparative Pathology 2014A captive garter snake (Thamnophis sirtalis) showed marked circumferential thickening of the body wall due to a chronic fibrous to necrotizing inflammatory reaction...
A captive garter snake (Thamnophis sirtalis) showed marked circumferential thickening of the body wall due to a chronic fibrous to necrotizing inflammatory reaction extending from the serosa to the skin. The lesions were associated with the presence of intra- and extracellular microsporidian organisms. With ultrastructural and molecular analyses the microsporidia were identified as Heterosporis anguillarum. This organism causes a morphologically similar disease in the Japanese eel (Anguilla japonica), but this is the first time it has been identified in an infected reptile.
Topics: Animals; Colubridae; Microsporidiosis; Pleistophora
PubMed: 24011905
DOI: 10.1016/j.jcpa.2013.07.009