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Journal of Invertebrate Pathology Jul 2003We have isolated a microsporidium from a laboratory stock of the European grape vine moth, Lobesia botrana Den. et Schiff. (Lepidoptera, Tortricidae). Screening of this... (Comparative Study)
Comparative Study
Morphological and molecular investigations of a microsporidium infecting the European grape vine moth, Lobesia botrana Den. et Schiff., and its taxonomic determination as Cystosporogenes legeri nov. comb.
We have isolated a microsporidium from a laboratory stock of the European grape vine moth, Lobesia botrana Den. et Schiff. (Lepidoptera, Tortricidae). Screening of this stock showed an infection rate of more than 90%, whereas field collected larvae from three different locations in Rhineland-Palatinate (Germany) did not demonstrate any signs of infection. Light and electron microscopic investigations of infected insects showed that gross pathology, morphology, and ultrastructure of the microsporidium are similar to those described earlier for Pleistophora legeri. Comparative phylogenetic analysis of the small subunit rDNA using maximum likelihood, maximum parsimony, and neighbour joining distance methods showed that our isolate was closely related to Cystosporogenes operophterae. Based on our morphological and molecular investigations we propose to rename this species Cystosporogenes legeri nov. comb.
Topics: Animals; Base Sequence; DNA, Protozoan; DNA, Ribosomal; Microscopy, Electron; Microsporidia, Unclassified; Microsporidiosis; Molecular Sequence Data; Moths; Phylogeny; Polymerase Chain Reaction; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid
PubMed: 12877831
DOI: 10.1016/s0022-2011(03)00104-6 -
International Journal For Parasitology Jul 2003In its freshwater amphipod host Gammarus duebeni celticus, the microsporidian parasite Pleistophora mulleri showed 23% transmission efficiency when uninfected...
In its freshwater amphipod host Gammarus duebeni celticus, the microsporidian parasite Pleistophora mulleri showed 23% transmission efficiency when uninfected individuals were fed infected tissue, but 0% transmission by water-borne and coprophagous routes. Cannibalism between unparasitised and parasitised individuals was significantly in favour of the former (37% compared to 0%). In addition, cannibalism between parasitised individuals was significantly higher than between unparasitised individuals (27% compared to 0%). Thus, parasitised individuals were more likely to be cannibalised by both unparasitised and parasitised individuals. We discuss the conflicting selective forces within this host/parasite relationship, the implications of parasite mediated cannibalism for host population structure and the impacts this may have on the wider aquatic community.
Topics: Animals; Behavior, Animal; Cannibalism; Crustacea; Fresh Water; Host-Parasite Interactions; Microsporidiosis; Pleistophora
PubMed: 12865079
DOI: 10.1016/s0020-7519(03)00110-3 -
Proceedings. Biological Sciences Jun 2003Parasites can structure biological communities directly through population regulation and indirectly by processes such as apparent competition. However, the role of...
Parasites can structure biological communities directly through population regulation and indirectly by processes such as apparent competition. However, the role of parasites in the process of biological invasion is less well understood and mechanisms of parasite mediation of predation among hosts are unclear. Mutual predation between native and invading species is an important factor in determining the outcome of invasions in freshwater amphipod communities. Here, we show that parasites mediate mutual intraguild predation among native and invading species and may thereby facilitate the invasion process. We find that the native amphipod Gammarus duebeni celticus is host to a microsporidian parasite, Pleistophora sp. (new species), with a frequency of infection of 0-90%. However, the parasite does not infect three invading species, G. tigrinus, G. pulex and Crangonyx pseudogracilis. In field and laboratory manipulations, we show that the parasite exhibits cryptic virulence: the parasite does not affect host fitness in single-species populations, but virulence becomes apparent when the native and invading species interact. That is, infection has no direct effect on G. d. celticus survivorship, size or fecundity; however, in mixed-species experiments, parasitized natives show a reduced capacity to prey on the smaller invading species and are more likely to be preyed upon by the largest invading species. Thus, by altering dominance relationships and hierarchies of mutual predation, parasitism strongly influences, and has the potential to change, the outcome of biological invasions.
Topics: Amphipoda; Animals; Female; Host-Parasite Interactions; Ireland; Male; Parasites; Population Dynamics; Predatory Behavior; Virulence
PubMed: 12816645
DOI: 10.1098/rspb.2003.2358 -
The Journal of Eukaryotic Microbiology 2003This report provides a detailed ultrastructural study of the life cycle, including proliferative and sporogonic developmental stages, of the first Pleistophora species...
This report provides a detailed ultrastructural study of the life cycle, including proliferative and sporogonic developmental stages, of the first Pleistophora species (microsporidium) obtained from an immune-incompetent patient. In 1985, the organism obtained from a muscle biopsy was initially identified as belonging to the genus Pleistophora, based on spore morphology and its location in a sporophorous vesicle. Since that initial report, at least two new microsporidial genera, Trachipleistophora and Brachiola, have been reported to infect the muscle tissue of immunologically compromised patients. Because Trachipleistophora development is similar to Pleistophora, and as Pleistophora was only known to occur in cold-blooded hosts, the question of the proper classification of this microsporidium arose. The information acquired in this study makes it possible to compare Pleistophora sp. (Ledford et al. 1985) to the known human infections and properly determine its correct taxonomic position. Our ultrastructural data have revealed the formation of multinucleate sporogonial plasmodia, a developmental characteristic of the genus Pleistophora and not Trachipleistophora. A comparison with other species of the genus supports the establishment of a new species. This parasite is given the name Pleistophora ronneafiei n. sp.
Topics: Animals; Humans; Immunocompromised Host; Male; Microsporidia; Microsporidiosis; Muscle, Skeletal; Myositis; Spores, Protozoan
PubMed: 12744518
DOI: 10.1111/j.1550-7408.2003.tb00237.x -
International Journal For Parasitology Feb 2003Structural diversity of fish microsporidian life cycle stages and of the host-parasite interface is reviewed. In the infected cell of the fish host, microsporidia may... (Review)
Review
Structural diversity of fish microsporidian life cycle stages and of the host-parasite interface is reviewed. In the infected cell of the fish host, microsporidia may either cause serious degradation of the cytoplasm and demise of the cell, or they may elicit host cell hypertrophy, producing a parasite-hypertrophic host cell complex, the xenoma. The structure of the xenoma and of its cell wall may differ according to the genus of the parasite, and seems to express properties of the parasite rather than those of the host. In merogony, the parasite cell surface interacts with the host cell in diverse ways, the most conspicuous being the production of thick envelopes of different types. Sporogony stages reveal different types of walls or membranes encasing the sporoblasts and later the spores and these envelopes may be of host or parasite origin. Nucleospora differs from all other fish microsporidia by its unique process of sporogony. Except for the formation of conspicuous xenomas, there are no essentially different structures in fish-infecting microsporidia compared with microsporidia from other hosts. Although the structures associated with the development of fish microsporidia cannot be attributed importance in tracing the phylogeny, they are relevant for practical determination and assessing the relation to the host. The possibility of the existence of an intermediate host is discussed. Higher-level classification of Microsporidia is briefly discussed and structure and evolutionary rates in microsporidian rDNA are reviewed. Discussion of rDNA molecular phylogeny of fish-infecting microsporidia is followed by classification of these parasites. Most form a rather cohesive clade. Outside this clade is the genus Nucleospora, separated at least at the level of Order. Within the main clade, however, there are six species infecting hosts other than fish. Based on data available for analysis, a tentative classification of fish-infecting microsporidia into five groups is proposed. Morphologically defined groups represent families, others are referred to as clades. Group 1, represented by family Pleistophoridae, includes Pleistophora, Ovipleistophora and Heterosporis; Vavraia and Trachipleistophora infect non-fish hosts. Group 2, represented by family Glugeidae, is restricted to genus Glugea and Tuzetia weidneri from crustaceans. Group 3 comprises three clades: Loma and a hyperparasitic microsporidian from a myxosporean; Ichthyosporidium and Pseudoloma clade and the Loma acerinae clade. For the latter species a new genus has to be established. Group 4 contains two families, Spragueidae with the genus Spraguea and Tetramicridae with genera Microgemma and Tetramicra, and the Kabatana and Microsporidium seriolae clade. Group 5 is represented by the family Enterocytozoonidae with the genus Nucleospora and mammal-infecting genus Enterocytozoon.
Topics: Animals; DNA, Ribosomal; Fishes; Life Cycle Stages; Microsporidia; Oligonucleotide Array Sequence Analysis; Phylogeny
PubMed: 12633649
DOI: 10.1016/s0020-7519(02)00252-7 -
Diseases of Aquatic Organisms Mar 2002Based on ultrastructural study and molecular analysis, a new genus, Ovipleistophora, is established for Pleistophora mirandellae-like microsporidia from roach and ruff...
Based on ultrastructural study and molecular analysis, a new genus, Ovipleistophora, is established for Pleistophora mirandellae-like microsporidia from roach and ruff oocytes. Unlike Pleistophora, Ovipleistophora has a thick additional envelope around the meront. This envelope breaks open to release the cells into the host cell cytoplasm. The cells, becoming multinuclear sporogonic plasmodia, already have a surface coat that transforms into the sporont wall and eventually into the sporophorous vesicle wall. The surface coat and its transformation differ from those of Pleistophora, but bear some resemblance to those of Trachipleistophora. In Trachipleistophora the sporonts, however, do not form plasmodia, as they do in Ovipleistophora and Pleistophora. Small subunit ribosomal DNA analysis supports the establishment of the new genus and assignment of P. mirandellae from 2 different fish hosts to the same species. The same small subunit ribosomal DNA analysis lends support for transferring P. ovariae into the genus Ovipleistophora.
Topics: Animals; Cyprinidae; DNA, Protozoan; DNA, Ribosomal; Fish Diseases; Microscopy, Electron; Microsporida; Microsporidiosis; Perches; Phylogeny; Polymerase Chain Reaction; RNA, Protozoan; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 12005235
DOI: 10.3354/dao048133 -
Journal of Food Protection Feb 2002The occurrence of human pathogenic parasites in irrigation waters used for food crops traditionally eaten raw was investigated. The polymerase chain reaction was used to...
The occurrence of human pathogenic parasites in irrigation waters used for food crops traditionally eaten raw was investigated. The polymerase chain reaction was used to detect human pathogenic microsporidia in irrigation waters from the United States and several Central American countries. In addition, the occurrence of both Cryptosporidium oocysts and Giardia cysts was determined by immunofluorescent techniques. Twenty-eight percent of the irrigation water samples tested positive for microsporidia, 60% tested positive for Giardia cysts, and 36% tested positive for Cryptosporidium oocysts. The average concentrations in samples from Central America containing Giardia cysts and Cryptosporidium oocysts were 559 cysts and 227 oocysts per 100 liters. In samples from the United States, averages of 25 Giardia cysts per 100 liters and <19 (average detection limit) Cryptosporidium oocysts per 100 liters were detected. Two of the samples that were positive for microsporidia were sequenced, and subsequent database homology comparisons allowed the presumptive identification of two human pathogenic species, Encephalitozoon intestinalis (94% homology) and Pleistophora spp. (89% homology). The presence of human pathogenic parasites in irrigation waters used in the production of crops traditionally consumed raw suggests that there may be a risk of infection to consumers who come in contact with or eat these products.
Topics: Animals; Cryptosporidium; DNA, Protozoan; Food Contamination; Giardia; Microsporidia; Oocytes; Polymerase Chain Reaction; Sequence Homology; Species Specificity; Vegetables; Water
PubMed: 11848571
DOI: 10.4315/0362-028x-65.2.378 -
Parasite (Paris, France) Jun 2001Myositis is a common clinical syndrome in advanced stages of AIDS. Trachipleistophora hominis (phylum Microspora) has been detected in several cases of painful,...
Myositis is a common clinical syndrome in advanced stages of AIDS. Trachipleistophora hominis (phylum Microspora) has been detected in several cases of painful, immobilising myositis in AIDS patients. Enzyme linked immunosorbent assays (ELISAs) and Western blotting of protein profiles separated by SDS PAGE were used to determine whether this species could be detected and differentiated by serology. Sixteen microsporidia, including several species known to infect man and species infecting fish, crustaceans and a mosquito, were used as antigen. Each species had a unique profile of SDS PAGE-separated proteins. In Western blots, mouse antiserum, raised to T. hominis and selected for its high ELISA specificity, bound to antigens ranging from less than 25 kDa to greater than 250 kDa with major bands at 39-44 kDa and 98-150 kDa on T. hominis protein profiles. The serum also recognised some high molecular weight antigens in the profiles of Vavraia culicis, Heterosporis anguillarum, and three species of Pleistophora but none in the remaining genera examined. It was concluded that ELISA and Western blotting could be used to detect and differentiate T. hominis in muscle biopsy tissue from patients with myositis. However, sera from T. hominis-infected patients in the terminal stages of AIDS would not be useful for detection of infections because of a sharp decline in antibody level.
Topics: AIDS-Related Opportunistic Infections; Animals; Antigens, Protozoan; Blotting, Western; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Humans; Microsporidia; Microsporidiosis; Molecular Weight; Myositis; Serotyping
PubMed: 11474986
DOI: 10.1051/parasite/2001082091 -
The Journal of Eukaryotic Microbiology 2001Molecular data have proved useful as an alternative to morphological data in showing the relationships of genera within the phylum Microsporidia, but until now have been...
Molecular data have proved useful as an alternative to morphological data in showing the relationships of genera within the phylum Microsporidia, but until now have been available only for ribosomal genes. In previous studies protein-coding genes of microsporidia have been used only to assess their position in the evolution of eukaryotes. For the first time we report on the use of a protein-coding gene, the A-G region of the largest subunit of RNA polymerase II (RPB1) from 14 mainly polysporous species, to generate an alternative phylogeny for microsporidia. Using the amino acid sequences, the genera and species fell into the same main groupings as had been obtained with 16S rDNA sequences, but the RPB1 data provided better resolution within these groups. The results supported the pairings of Trachipleistophora hominis with Vavraia culicis and Pleistophora hippoglossoideos with Pleistophora typicalis. They also confirmed that the genus Pleistophora is not monophyletic and that it will be necessary to transfer Pleistophora ovariae and Pleistophora mirandellae into one or more other genera, as has already been effected for Pleistophora anguillarum.
Topics: Animals; DNA, Protozoan; Fishes; Humans; Insecta; Microsporidia; Microsporidiosis; Molecular Sequence Data; Phylogeny; RNA Polymerase II; Sequence Analysis, DNA
PubMed: 11249186
DOI: 10.1111/j.1550-7408.2001.tb00422.x -
Acta Tropica Feb 2001Microsporidia are eukaryotic spore forming obligate intracellular protozoan parasites first recognized over 100 years ago. These organisms infect all of the major animal... (Review)
Review
Microsporidia are eukaryotic spore forming obligate intracellular protozoan parasites first recognized over 100 years ago. These organisms infect all of the major animal groups and are now recognized as opportunistic pathogens of humans. Microsporidian spores are common in the environment and microsporidia pathogenic to humans have been found in water supplies. The genera Nosema, Vittaforma, Brachiola, Pleistophora, Encephalitozoon, Enterocytozoon, Septata (reclassified to Encephalitozoon) and Trachipleistophora have been found in human infections. These organisms have the smallest known eukaryotic genomes. Microsporidian ribosomal RNA sequences have proven useful as diagnostic tools as well as for phylogenetic analysis. Recent phylogenetic analysis suggests that Microsporidia are related to the fungi. These organisms are defined by the presence of a unique invasion organelle consisting of a single polar tube that coils around the interior of the spore. All microsporidia exhibit the same response to stimuli, that is, the polar tube discharges from the anterior pole of the spore in an explosive reaction. If the polar tube is discharged next to a cell, it can pierce the cell and transfer its sporoplasm into the cell. A technique was developed for the purification of polar tube proteins (PTPs) using differential extraction followed by reverse phase HPLC. This method was used to purify the PTPs from Glugea americanus, Encephalitozoon cuniculi, Enc. hellem and Enc. intestinalis. These PTPs demonstrate conserved characteristics such as solubility, hydrophobicity, mass, proline content and immunologic epitopes. The major PTP gene from Enc. cuniculi and Enc. hellem has been cloned and expressed in vitro. The gene sequences support the importance of ER and in the formation of the polar tube as suggested by morphologic studies. Analysis of the cloned proteins also indicates that secondary structural characteristics are conserved. These characteristics are probably important in the function of this protein during the eversion/assembly of the polar tube and in providing elasticity and resiliency for sporoplasm passage.
Topics: Amino Acid Sequence; Animals; Humans; Microsporidia; Microsporidiosis; Molecular Sequence Data; Phylogeny; Sequence Homology, Amino Acid
PubMed: 11230819
DOI: 10.1016/s0001-706x(00)00178-9