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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 -
The Journal of Eukaryotic Microbiology 2003The classification of a microsporidian parasite observed in the abdominal muscles of amphipod hosts has been repeatedly revised but still remains inconclusive. This...
The classification of a microsporidian parasite observed in the abdominal muscles of amphipod hosts has been repeatedly revised but still remains inconclusive. This parasite has variable spore numbers within a sporophorous vesicle and has been assigned to the genera Glugea, Pleistophora, Stempellia, and Thelohania. We used electron microscopy and molecular evidence to resolve the previous taxonomic confusion and confirm its identification as Pleistophora mulleri. The life cycle of P. mulleri is described from the freshwater amphipod host Gammarus duebeni celticus. Infection appeared as white tubular masses within the abdominal muscle of the host. Light and transmission electron microscope examination revealed the presence of an active microsporidian infection that was diffuse within the muscle block with no evidence of xenoma formation. Paucinucleate merogonial plasmodia were surrounded by an amorphous coat immediately external to the plasmalemma. The amorphous coat developed into a merontogenetic sporophorous vesicle that was present throughout sporulation. Sporogony was polysporous resulting in uninucleate spores, with a bipartite polaroplast, an anisofilar polar filament and a large posterior vacuole. SSU rDNA analysis supported the ultrastructural evidence clearly placing this parasite within the genus Pleistophora. This paper indicates that Pleistophora species are not restricted to vertebrate hosts.
Topics: Animals; DNA, Protozoan; DNA, Ribosomal; Microscopy, Electron; Molecular Sequence Data; Phylogeny; Pleistophora; Spores
PubMed: 15132170
DOI: 10.1111/j.1550-7408.2003.tb00133.x -
Parasitology Research Oct 2012A potentially fatal microsporidial infection targeting the skeletal muscles of the tiger barb Puntius tetrazona was described. Ultrastructural and molecular analyses of...
A potentially fatal microsporidial infection targeting the skeletal muscles of the tiger barb Puntius tetrazona was described. Ultrastructural and molecular analyses of infected tissues confirmed that the causative parasite was Pleistophora hyphessobryconis. Compared to P. hyphessobryconis observed in other hosts, those infecting tiger barb demonstrated differences in ultrastructure that may be related to host adaptation. Phylogenetic analysis revealed that classifications based on different methods of analysis (molecular, morphologic, or developmental) do not always coincide, and suggesting that the genetic relationships between Pleistophora and Ovipleistophora may need to be redefined. Transparent mutants of tiger barb can be artificially infected by P. hyphessobryconis, and the dynamic process and spatial distribution of P. hyphessobryconis infection can be observed in real time. These transparent fish mutants are a valuable model to study microsporidial infection in vivo.
Topics: Animals; Cluster Analysis; Cyprinidae; Fish Diseases; Genes, rRNA; Microscopy, Electron, Transmission; Microsporidiosis; Molecular Sequence Data; Phylogeny; Pleistophora; RNA, Fungal; RNA, Ribosomal, 18S; Sequence Analysis, DNA
PubMed: 22773044
DOI: 10.1007/s00436-012-3013-8 -
Journal of Fish Diseases Nov 2005Pleistophora infestation was observed in adult fathead minnows, Pimephales promelas, held under laboratory conditions. Fish were clinically healthy, and presented no... (Comparative Study)
Comparative Study
Pleistophora infestation was observed in adult fathead minnows, Pimephales promelas, held under laboratory conditions. Fish were clinically healthy, and presented no gross findings at necropsy. Histopathology revealed parasitic stages only in the ovaries. Spores within sporophorous vesicles were mainly encountered in late vitellogenic oocytes and were ultrastructurally identified as a microsporidian parasite. Heavily parasitized oocytes underwent degeneration followed by the release of spores into the ovarian interstitium. Degenerating oocytes and interstitial spores caused ovarian inflammation. Male fish showed no parasites in the testes. Parasitic infestation was compared with body length, body weight, gonadal weight, gonadosomatic index and plasma vitellogenin levels, and revealed no statistically significant differences between non-parasitized and parasitized females. The isolated holding conditions of the fish and the presence of parasitic stages in the ovaries suggested that an infestation with Pleistophora ovariaeSummerfelt, 1964 was more probable than that with Pleistophora mirandellae (Vaney & Conte, 1901).
Topics: Animals; Body Weights and Measures; Cyprinidae; Enzyme-Linked Immunosorbent Assay; Female; Fish Diseases; Male; Microscopy, Electron; Microsporidiosis; Organ Size; Ovary; Pleistophora; Spores, Fungal; Vitellogenins
PubMed: 16303025
DOI: 10.1111/j.1365-2761.2005.00661.x -
Parasitology Research Feb 2012One hundred three out of 225 (45.8%) of the Red Sea fish Saurida tumbil were infected with microsporidian parasites. The infection was recorded as tumor-like masses...
One hundred three out of 225 (45.8%) of the Red Sea fish Saurida tumbil were infected with microsporidian parasites. The infection was recorded as tumor-like masses (whitish macroscopic cysts) or xenomas often up to 2 cm in diameter and embedded in the peritoneal cavity. Generally, the infection was increased during winter 63.8% (86 out of 135) and fall to 18.9% (17 out of 90) in summer. Light microscopic study revealed that xenomas were encapsulated by a fibrous layer encircling numerous sporophorous vesicles filled with mature spores measuring 1.7 ± 0.6 (1.5-2.7 μm) × 1.5 ± 0.3 μm (1.2-1.8 μm) in size. Ultrastructural microscopic study showed the presence of smooth membranes of the sarcoplasmic reticulum forming a thick, amorphous coat surrounding various developmental stages of the parasite. The various recognizable stages of the parasite were uninuclear, binucleated, and multinucleated meronts followed by detachment of the plasmalemma of the sporont from the sporophorous vesicle producing sporoblasts. Mature spores consist of a spore coat and spore contents. The spore contents consist of the uninucleated sporoplasm and a posterior vacuole located at the posterior end. The polar tube consists of a straight shaft and a coiled region (26-32 coils) arranged in many rows along the inside periphery of the spore. The polaroplast consisted of an anterior region of closely and loosely packed membranes. Molecular analysis based on the small subunit rDNA gene was performed to determine the phylogenetic position of the present species. The percentage identity between this species and a range of other microsporidia predominantly from aquatic hosts demonstrated a high degree of similarity (>92%) with eight Pleistophora species. Comparison of the nucleotide sequences and divergence showed that the sequence of the present microsporidium was most similar to that of Pleistophora anguillarum (99.8% identity) differing in 13 nucleotide positions. So, the present species was recorded and phylogenetically positioned as a new species of Pleistophora.
Topics: Animals; Chordata; Cluster Analysis; DNA, Fungal; DNA, Ribosomal; Fish Diseases; Genes, rRNA; Histocytochemistry; Incidence; Indian Ocean; Microscopy; Microsporidiosis; Molecular Sequence Data; Phylogeny; Pleistophora; RNA, Fungal; RNA, Ribosomal, 18S; Seasons; Sequence Analysis, DNA; Spores, Fungal
PubMed: 21858478
DOI: 10.1007/s00436-011-2597-8 -
Parasitology Sep 2005The microsporidian parasite, Pleistophora mulleri, infects the abdominal muscle of the freshwater amphipod Gammarus duebeni celticus. We recently showed that P. mulleri...
The microsporidian parasite, Pleistophora mulleri, infects the abdominal muscle of the freshwater amphipod Gammarus duebeni celticus. We recently showed that P. mulleri infection was associated with G. d. celticus hosts being more vulnerable to predation by the invasive amphipod Gammarus pulex. Parasitized G. d. celticus also had a reduced ability to prey upon other co-occurring amphipods. We suggested the parasite may have pervasive influences on host ecology and behaviour. Here, we examine the association between P. mulleri parasitism and parameters influencing individual host fitness, behaviour and interspecific interactions. We also investigate the relationship between parasite prevalence and host population structure in the field. In our G. d. celticus study population, P. mulleri prevalence was strongly seasonal, ranging from 8.5% in summer to 44.9% in winter. The relative abundance of hosts with the heaviest parasite burden increased during summer, which coincided with high host mortality, suggesting that parasitism may regulate host abundance to some degree. Females were more likely to be parasitized than males and parasitized males were paired with smaller females than unparasitized males. Parasitism was associated with reduction in the host's activity level and reduced both its predation on the isopod Asellus aquaticus and aggression towards precopula pairs of the invasive G. pulex. We discuss the pervasive influence of this parasite on the ecology of its host.
Topics: Amphipoda; Animals; Ecosystem; Host-Parasite Interactions; Pleistophora; Seasons
PubMed: 16178354
DOI: 10.1017/s0031182005007754 -
Parazitologiia 1975A new species of Microsporidia, Pleistiophora carpocapsae sp. n., a parasite of caterpillars and pupae of the codling moth, is described from Moldavia. It is noteworthy...
A new species of Microsporidia, Pleistiophora carpocapsae sp. n., a parasite of caterpillars and pupae of the codling moth, is described from Moldavia. It is noteworthy that one sporant forms pansporoblasts containing from 4 to 64 sporoblasts and then the same number of spores.
Topics: Animals; Lepidoptera; Microsporida; Moths
PubMed: 1235417
DOI: No ID Found -
Parazitologiia 1978The parasite develops inside the fibres of the cross-striated musculature. On the histologic sections of the affected tissue most young stages of P. ladogensis are...
Pleistophora ladogensis sp. n., a microsporidian (Protozoa, Microsporidia) from the musculature of the burbot, Lota lota, and of the smelt, Osmerus eperlanus eperlanus ladogensis.
The parasite develops inside the fibres of the cross-striated musculature. On the histologic sections of the affected tissue most young stages of P. ladogensis are represented by 2--6 nucleic cells 5--6 mu in size. Mature pansporoblasts have a thick and solid membrane. Their average size is 43 (18--60) mu. The number of spores in pansporoblasts is over 16. Live spores are egg-shaped and are 5.4 (5.0--5.8).2.9 (2.7--3.3) mu in size. The length of the polar filament is 100 to 180 mu.
Topics: Animals; Apicomplexa; Fishes; Muscles; Russia; Spores
PubMed: 151848
DOI: No ID Found -
Parazitologiia 1975
Topics: Animals; Larva; Lepidoptera; Microsporida; Moldova; Moths; Pupa
PubMed: 127972
DOI: No ID Found -
Parasitology Research 1996The wall of the younger sporophorous vesicle (enclosing the sporogogonial plasmodium) of Pleistophora mirandellae Vaney and Conte, 1901 is composed of a membranous...
The wall of the younger sporophorous vesicle (enclosing the sporogogonial plasmodium) of Pleistophora mirandellae Vaney and Conte, 1901 is composed of a membranous labyrinth, about 0.3-0.6 microns high, interwoven with host cell cytoplasm. There is electron-opaque matter within the partitions of the labyrinth. At the onset of plasmotomy, the partitions of the labyrinth become shorter and then possibly due to stretching of the wall and withdrawal of the membranes, the electron-opaque matter is ejected to the lumen side of the wall and the partitions disappear. Only cisterna-like remains of the partitions are observable outside the electron-opaque layer. The thickness of walls in vesicles with ripe spores can be even less than 100 nm.
Topics: Animals; Microsporida
PubMed: 8897511
DOI: 10.1007/s004360050195