An analysis of the microsporidian genus Brachiola, with comparisons of human and insect isolates of Brachiola algerae. (1/9)

The genus Brachiola is the newest microsporidian genus established for a human infection with the type species being B. vesicularum in skeletal muscle. Subsequently, the microsporidium, Nosema algerae, identified from mosquitoes, was added to this genus because of morphological and physiological similarities. The present report illustrates a confirmed case of Brachiola algerae infecting skeletal muscle in a 56-year-old woman who was being treated for rheumatoid arthritis with immunosuppressive drugs. In the following study, these two human-infecting microsporidian species are ultrastructurally compared from human biopsy tissue. Additionally, Brachiola algerae from mosquitoes as reference B. algerae, was grown in athymic mice and compared to the human isolate in vivo, and in culture. B. algerae is morphologically identical in the host situations presented and different from B. vesicularum in human skeletal muscle. B. algerae has a consistently, slightly longer spore that typically contains one row of polar filament coils, while B. vesicularum typically contains two rows of polar filament coils and occasionally, one or three rows. In proliferative development, B. vesicularum forms protoplasmic extensions which do not occur on B. algerae, nor have they been reported on any other microsporidium. This report demonstrates that B. vesicularum and B. algerae are two different species of Brachiola that infect human skeletal muscle.  (+info)

Investigations into microsporidian methionine aminopeptidase type 2: a therapeutic target for microsporidiosis. (2/9)

The Microsporidia have been reported to cause a wide range of clinical diseases particularly in patients that are immunosuppressed. They can infect virtually any organ system and cases of gastrointestinal infection, encephalitis, ocular infection, sinusitis, myositis and disseminated infection are well described in the literature. While benzimidazoles such as albendazole are active against many species of Microsporidia, these drugs do not have significant activity against Enterocytozoon bieneusi. Fumagillin, ovalicin and their analogues have been demonstrated to have antimicrosporidial activity in vitro and in animal models of microsporidiosis. Fumagillin has also been demonstrated to have efficacy in human infections due to E. bieneusi. Fumagillin is an irreversible inhibitor of methionine aminopeptidase type 2 (MetAP2). Homology cloning employing the polymerase chain reaction was used to identify the MetAP2 gene from the human pathogenic microsporidia Encephalitozoon cuniculi, Encephalitozoon hellem, Encephalitozoon intestinalis, Brachiola algerae and E. bieneusi. The full-length MetAP2 coding sequence was obtained for all of the Encephalitozoonidae. Recombinant E. cuniculi MetAP2 was produced in baculovirus and purified using chromatographic techniques. The in vitro activity and effect of the inhibitors bestatin and TNP-470 on this recombinant microsporidian MetAP2 was characterized. An in silico model of E. cuniculi MetAP2 was developed based on crystallographic data on human MetAP2. These reagents provide new tools for the development of in vitro assay systems to screen candidate compounds for use as new therapeutic agents for the treatment of microsporidiosis.  (+info)

Description of a xenoma-inducing microsporidian, Microgemma tincae n. sp., parasite of the teleost fish Symphodus tinca from Tunisian coasts. (3/9)

A xenoma-inducing microsporidian species was found to infect the liver of the teleost fish, peacock wrasse Symphodus (Crenilabrus) tinca. Minimal estimates of the prevalence of the parasite in fishes caught along Tunisian coasts were as high as 43 % for Bizerte samples (over 2 yr) and 72% for Monastir samples (over 3 yr). Developmental stages were dispersed within a xenoma structure that was bounded only by the plasma membrane of the hypertrophic host cell. Ultrastructural features support allocation to the genus Microgemma Ralphs and Matthews, 1986. Meronts were multinucleate plasmodia and were surrounded by rough endoplasmic reticulum (RER) of the host cell. Merogonic plasmodia developed into sporogonic plasmodia, with loss of the RER interface. Sporogony was polysporoblastic. Ovocylindrical spores (3.6 x 1.2 microm) harbored a lamellar polaroplast and a polar tube that was coiled 9 times. Spore features and host specificity led us to propose a new species, Microgemma tincae. The conversion of M. tincae xenomas into well-visible cyst structures or granulomas reflected an efficient host response involving the infiltration of phagocytic cells, degradation of various parasite stages and formation of a thick fibrous wall. The small subunit rDNA gene of M. tincae was partially sequenced. Phylogenetic analysis confirms the placement within the family Tetramicriidae represented by the genera Tetramicra and Microgemma.  (+info)

Genome sequence surveys of Brachiola algerae and Edhazardia aedis reveal microsporidia with low gene densities. (4/9)

 (+info)

Original observations of Desmozoon lepeophtherii, a microsporidian hyperparasite infecting the salmon louse Lepeophtheirus salmonis, and its subsequent detection by other researchers. (5/9)

 (+info)

Lack of phenotypic and evolutionary cross-resistance against parasitoids and pathogens in Drosophila melanogaster. (6/9)

 (+info)

Nucleospora cyclopteri n. sp., an intranuclear microsporidian infecting wild lumpfish, Cyclopterus lumpus L., in Icelandic waters. (7/9)

 (+info)

The genome of Spraguea lophii and the basis of host-microsporidian interactions. (8/9)

 (+info)

• 1
• 2