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Diseases of Aquatic Organisms Dec 2000This study presents the ultrastructure of the microsporidian infecting the trunk musculature of Anguilla japonica and originally described as Pleistophora anguillarum...
This study presents the ultrastructure of the microsporidian infecting the trunk musculature of Anguilla japonica and originally described as Pleistophora anguillarum Hoshina, 1959. All stages develop within a special structure, the sporophorocyst (SPC), which is equipped with a thick dense wall. This wall grows along with the growth of the parasites within it. Meronts are uni- to binucleate, which divide and steadily give rise to sporonts. During transition to sporonts the cell coat of the meronts increases its thickness, temporarily featuring thick irregular projections. Eventually a uniformly thick sporont wall is formed, then the sporont cells detach themselves from the wall (= future wall of the sporophorous vesicle, SPV) and start a series of divisions to produce sporoblasts. The SPV wall is compact, has no pores and consists of 2 layers. The presence of the SPC justifies the transfer of the species into the genus Heterosporis. Spores from disrupted SPCs are ingested by macrophages and within them are spread into various body tissues including the outermost layers of the epidermis. From here, they can easily be released to the outside and can contaminate the environment while the host is still alive.
Topics: Anguilla; Animals; Fish Diseases; Microscopy, Electron; Microsporidia; Microsporidiosis; Muscles
PubMed: 11206738
DOI: 10.3354/dao043225 -
International Journal For Parasitology Nov 2000The environmental route of transmission is important for many protozoan and helminth parasites, with water, soil and food being particularly significant. Both the... (Review)
Review
The environmental route of transmission is important for many protozoan and helminth parasites, with water, soil and food being particularly significant. Both the potential for producing large numbers of transmissive stages and their environmental robustness, being able to survive in moist microclimates for prolonged periods of time, pose a persistent threat to public and veterinary health. The increased demands on natural resources increase the likelihood of encountering environments and produce contaminated with parasites. For waterborne diseases, the protozoa, Cryptosporidium, Giardia and Toxoplasma, are the most significant causes, yet, with the exception of Toxoplasma, the contribution of zoonotic transmission remains unclear due to the absence of 'standardised' methods. The microsporidia have been documented in one waterborne outbreak, but the role of animals as the cause of contamination was not elucidated. In foods, surface contamination is associated with the faecal-oral pathogens, and some data are available to indicate that animal wastes remain an important source of contamination (e.g. cattle faeces and apple cider outbreaks), however, further work should focus on examining the source of contamination on fruit and vegetables. Increasing recognition of the burden of human fascioliasis has occurred; it is now recognised as an emerging zoonosis by the WHO. Toxoplasma, Trichinella and Taenia spp. remain important meatborne parasites, however, others, including Pleistophora-like microsporidians may be acquired from raw or lightly cooked fish or crustaceans. With increased international travel, the public health importance of the foodborne trematodiases must also be realised. Global sourcing of food, coupled with changing consumer vogues, including the consumption of raw vegetables and undercooking to retain the natural taste and preserve heat-labile nutrients, can increase the risk of foodborne transmission. A greater awareness of parasite contamination of our environment and its impact on health has precipitated the development of better detection methods. Robust, efficient detection, viability and typing methods are required to assess risks and to further epidemiological understanding.
Topics: Animals; Cattle; Food Parasitology; Humans; Parasitic Diseases; Risk Factors; Water; Water Supply; Zoonoses
PubMed: 11113263
DOI: 10.1016/s0020-7519(00)00128-4 -
FEMS Immunology and Medical Microbiology Oct 2000In order to estimate the rate and seasonal variation of Enterocytozoon bieneusi contamination of surface water, sequential samples of water from the River Seine in...
In order to estimate the rate and seasonal variation of Enterocytozoon bieneusi contamination of surface water, sequential samples of water from the River Seine in France were collected during a 1-year period. Each sample (300-600 l) was submitted to sequential filtrations, and the filters were then examined for microsporidia using light microscopy and nested polymerase chain reaction (PCR) for E. bieneusi. Amplified products were hybridized with a E. bieneusi-specific probe. Twenty-five samples of water were analyzed during 1 year. Microscopic examination of stained filters proved unreliable for the identification of spores. Using nested PCR, 16 of 25 specimens were positive (64%). Unexpectedly, E. bieneusi was identified in only one sample by specific hybridization underlining the lack of specificity of ours primers. Nevertheless, using DNA sequence analysis, unknown microsporidia species were identified in eight cases, which had highest scores of homology with Vittaforma corneae or Pleistophora sp. This study shows a low rate of water contamination by E. bieneusi suggesting that the risk of waterborne transmission to humans is limited.
Topics: Animals; Blotting, Southern; DNA, Protozoan; Enterocytozoon; Follow-Up Studies; France; Fresh Water; Microsporidia; Pleistophora; Polymerase Chain Reaction; Sequence Homology, Nucleic Acid; Vittaforma; Water Microbiology
PubMed: 11024347
DOI: 10.1111/j.1574-695X.2000.tb01510.x -
The Journal of Eukaryotic Microbiology 2000The microsporidian Trachipleistophora hominis was isolated in vitro from the skeletal muscle of an AIDS patient. Since its discovery several more cases of myositis due...
Phylogenetic relationships of Pleistophora-like microsporidia based on small subunit ribosomal DNA sequences and implications for the source of trachipleistophora hominis infections.
The microsporidian Trachipleistophora hominis was isolated in vitro from the skeletal muscle of an AIDS patient. Since its discovery several more cases of myositis due to Trachipleistophora have been diagnosed but the source of infection is unknown. Morphologically, T. hominis most closely resembles Pleistophora and Vavraia, which undergo polysporous sporogony in sporophorous vesicles, but differs from these genera in the mode of formation of sporoblasts and in the morphology of the sporophorous vesicles. Alignment and analyses of the small subunit ribosomal DNA sequences of T. hominis and several other polysporoblastic genera indicated that its closest phylogenetic relationships were with species of the genera Pleistophora and Vavraia, in line with morphological predictions. The type species of the latter two genera are Pleistophora typicalis and Vavraia culicis; these are parasites of fish and mosquitoes, respectively. These results suggest two possible routes and sources of infection to AIDS patients, these being perorally by ingestion of inadequately cooked fish or crustaceans or percutaneously during a bloodmeal taken by a haematophagous insect. Support for an insect source has been provided by recent detection of a microsporidium from mosquitoes in human corneal tissue.
Topics: Acquired Immunodeficiency Syndrome; Animals; DNA, Ribosomal; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Microsporida; Microsporidiosis; Molecular Sequence Data; Muscle, Skeletal; Phylogeny; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Tissue Distribution
PubMed: 10847345
DOI: 10.1111/j.1550-7408.2000.tb00048.x -
Parasitology Feb 2000The phylogenetic relationships of the microsporidian species Microgemma caulleryi, Pleistophora finisterrensis and Tetramicra brevifilum were investigated on the basis...
The phylogenetic relationships of the microsporidian species Microgemma caulleryi, Pleistophora finisterrensis and Tetramicra brevifilum were investigated on the basis of restriction fragment length polymorphism (RFLP) analysis of PCR-amplified small-subunit rDNA (SSUrDNA). Using PCR primers specific for microsporidian SSUrDNA, a single product was obtained from each species, and heteroduplex analysis indicated a high degree of sequence homology among the 3 products. In RFLP analysis of the PCR-amplified SSUrDNA, the enzymes AluI and DdeI gave restriction patterns that differed among all 3 species. Phylogenetic analysis using restriction patterns as differential characters indicated that Microgemma caulleryi and Tetramicra brevifilum are more closely related to each other than to Pleistophora finisterrensis.
Topics: Animals; DNA Primers; DNA, Protozoan; DNA, Ribosomal; Deoxyribonucleases, Type II Site-Specific; Electrophoresis, Agar Gel; Fishes; Heteroduplex Analysis; Image Processing, Computer-Assisted; Microsporida; Microsporidiosis; Phylogeny; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length
PubMed: 10726273
DOI: 10.1017/s0031182099005405 -
The Journal of Parasitology Feb 2000Molecular data have proved useful in the study of microsporidia phylogeny. Previous studies have shown that there are several important differences between phylogenies...
Molecular data have proved useful in the study of microsporidia phylogeny. Previous studies have shown that there are several important differences between phylogenies based on rRNA and morphological data. In the present study, small subunit (SSU) rDNA sequences were obtained from 7 different fish-infecting microsporidia from 4 different genera (Glugea Thélohan, 1891, Loma Morrison and Sprague, 1981, Pleistophora Gurley, 1893, and Spraguea Weissenberg, 1976). The lengths of the SSU rDNA genes in these species were between 1,332 and 1,343 base pairs. Phylogenetic analysis was performed using parsimony, maximum likelihood, and Kimura 2-parameter with neighbor joining. The analyses revealed that the microsporidia could be divided into 3 major groups. With the exception of Nucleospora salmonis Hedrick, Groff, and Baxa, 1991, all the microsporidia infecting fishes occurred in the same group. The analysis showed that Pleistophora mirandellae Vaney and Conte, 1901 and Pleistophora aguillarum Hoshina, 1951 are not species of Pleistophora. Furthermore, the analysis showed that Loma is not a member of Glugeidae Thélohan, 1892.
Topics: Animals; DNA, Protozoan; DNA, Ribosomal; Fish Diseases; Fishes; Microsporida; Microsporidiosis; Phylogeny; Polymerase Chain Reaction; RNA, Protozoan; RNA, Ribosomal; Sequence Alignment; Sequence Analysis, DNA
PubMed: 10701575
DOI: 10.1645/0022-3395(2000)086[0128:SSRDPO]2.0.CO;2 -
The Journal of Eukaryotic Microbiology 2000The fatty acid composition of four microsporidian species (Glugea atherinae, Spraguea lophii, Glugea americanus, and Pleistophora mirandellae) and their host fishes has... (Comparative Study)
Comparative Study
The fatty acid composition of four microsporidian species (Glugea atherinae, Spraguea lophii, Glugea americanus, and Pleistophora mirandellae) and their host fishes has been determined using gas chromatography. Twenty-four fatty acids were identified with differences in relative abundance of fatty acids among the four parasites. Certain even-saturated fatty acids were found in a very high proportion: palmitic acid (16:0) represented one-third of total fatty acids in Pleistophora mirandellae. The level of docosahexaenoic acid (22:6omega3) attained 26-28% in Glugea atherinae, Spraguea lophii, and Glugea americanus, but only 8-9% in P. mirandellae. With respect to fatty acid compositions of host organs, some significant differences were evident between marine and freshwater fishes. Palmitic acid was prevalent in the marine fishes, Atherinae boyeri and Lophius piscatorius, and oleic acid (18:1omega9) in the freshwater fish Leuciscus cephalus. The proportion of docosahexaenoic acid in marine fishes was two or three times as great as in freshwater fish Leuciscus. The high polyunsaturated fatty acid content in both parasites and host fishes may be related to the scavenging of these fatty acids by the parasites rather than a microsporidia-specific fatty acid biosynthesis pathway.
Topics: Animals; Chromatography, Gas; Fatty Acids; Fish Diseases; Fishes; Fresh Water; Kidney; Liver; Microsporida; Microsporidiosis; Seawater; Spores
PubMed: 10651288
DOI: 10.1111/j.1550-7408.2000.tb00002.x -
The Journal of Eukaryotic Microbiology 1998Using the polymerase chain reaction (PCR) and two primers for conserved regions of the small subunit ribosomal RNA (SSU-rRNA) of Microsporidia, a DNA segment about 1,195...
Using the polymerase chain reaction (PCR) and two primers for conserved regions of the small subunit ribosomal RNA (SSU-rRNA) of Microsporidia, a DNA segment about 1,195 base pairs long was amplified from a DNA template prepared from purified spores of the microsporidian species Pleistophora anguillarum. These spores had been isolated from adult eels (Anguilla japonica) with "Beko Disease." A comparison of sequence data from other microsporidian species showed P. anguillarum SSU-rRNA to be most similar to Vavraia oncoperae. When juvenile eels were artificially infected with P. anguillarum, enzyme-linked immunosorbent assay could detect a positive infection only 12 days post-infection. However, when suitable PCR primers were used, a DNA fragment of about 0.8 kb was detected from these juvenile eels after only 3 days post infection. No PCR product was obtained with templates prepared from clinically healthy control animals.
Topics: Anguilla; Animals; Base Sequence; DNA Primers; DNA, Protozoan; DNA, Ribosomal; Fish Diseases; Genes, Protozoan; Microsporida; Molecular Sequence Data; Polymerase Chain Reaction; Protozoan Infections, Animal; RNA, Protozoan; RNA, Ribosomal; Spores
PubMed: 9783458
DOI: 10.1111/j.1550-7408.1998.tb05116.x -
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 -
The Journal of Eukaryotic Microbiology 1998Trachipleistophora anthropophthera n. sp., was found at autopsy in the brain of one and in the brain, kidneys, pancreas, thyroid, parathyroid, heart, liver, spleen,...
Microsporidia of the genus Trachipleistophora--causative agents of human microsporidiosis: description of Trachipleistophora anthropophthera n. sp. (Protozoa: Microsporidia).
Trachipleistophora anthropophthera n. sp., was found at autopsy in the brain of one and in the brain, kidneys, pancreas, thyroid, parathyroid, heart, liver, spleen, lymph nodes, and bone marrow of a second patient with AIDS. The parasite is similar to the recently described T. hominis Hollister, Canning, Weidner, Field, Kench and Marriott, 1996, in having isolated nuclei, meronts with a thick layer of electron dense material on the outer face of their plasmalemma and sporogony during which spores are formed inside a thick-walled sporophorous vesicle. In contrast to T. hominis, this species is dimorphic as it forms two kinds of sporophorous vesicles and spores: Type I--round to oval polysporous sporophorous vesicle, 7-10 microns in size, usually with eight spores (3.7 x 2.0 microns), thick endospores, subterminal anchoring disc and anisofilar polar filaments forming seven thicker and two thinner terminal coils. This type of sporophorous vesicle is associated with 25-30 nm filaments extending into the host cell cytoplasm. Type II--smaller, bisporous sporophorous vesicle (4-5 x 2.2-2.5 microns) with two, nearly round, thin-walled spores, 2.2-2.5 x 1.8-2.0 microns in size, having 4-5 isofilar coils. No outside filamentous elements are associated with the bisporous sporophorous vesicle. Both types of sporophorous vesicles were common in the infected brain tissue and could be found within the same cell. The newly described species, together with T. hominis and previously reported Pleistophora-like parasites from human muscle, likely represent a group of closely related human microsporidia.
Topics: AIDS-Related Opportunistic Infections; Animals; Brain; Heart; Humans; Kidney; Microscopy, Electron; Microscopy, Electron, Scanning; Microsporida; Microsporidiosis; Spores
PubMed: 9627987
DOI: 10.1111/j.1550-7408.1998.tb04536.x