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Microsporidian Species (microsporidian + species)

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Life Sciences100%

Selected Abstracts

Three microsporidian pathogens infecting Lymantria dispar larvae do not differ in their success in horizontal transmission

JOURNAL OF APPLIED ENTOMOLOGY, Issue 7 2009
D. Goertz
Abstract We quantified horizontal transmission of three microsporidian pathogens, Endoreticulatus schubergi, Nosema lymantriae and Vairimorpha disparis that infect Lymantria dispar larvae in an experiment using caged, potted oak plants. Despite marked differences in the modes of spore release from infectious hosts, no significant differences in the transmission success to uninfected, susceptible test hosts were ascertained between the tested microsporidian species. The density of initially inoculated larvae and the exposure period, on the other hand, did influence the number of infected test larvae. Depending on the density of inoculated larvae (10%, 30% or 50%), between 0% and 26% of the test larvae became infected with one of the three tested microsporidian pathogens after an exposure period of 6 days. When the exposure period was 12 days, between 11% and 76% of the test larvae became infected. [source]

Euplotespora binucleata n. gen., n. sp. (Protozoa: Microsporidia), a Parasite Infecting the Hypotrichous Ciliate Euplotes woodruffi, with Observations on Microsporidian Infections in Ciliophora

THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 3 2008
SERGEI I. FOKIN
ABSTRACT. A new microsporidian species, Euplotespora binucleata n. gen., n. sp., from the brackish-water ciliate Euplotes woodruffi is described and defined on the basis of life history characteristics, light and electron microscopic features, and small subunit (SSU) ribosomal DNA (rDNA) sequencing. The life cycle of E. binucleata n. sp. probably has rather short merogonic and relatively long sporogonic phases. Some uninuclear meronts and sporonts, along with diplokaryotic sporoblasts and spores, were found in experimentally infected host cells. Such a peculiar life cycle has been induced experimentally in Euplotes eurystomus and constitutively microsporidian-free stocks of E. woodruffi. Spores of E. binucleata n. sp. are monomorphic, ovoid,cylindrical in shape, 3.44±0.17 × 1.65±0.22 ,m in size, and characterized by a diplokaryotic condition and a large posterior vacuole. The polar tube is isofilar, 4.5,5.5 ,m in length when ejected, and lacking a distinctive coiled region (half-coiled). The polaroplast is divided into two regions: the anterior part has a few lamellae close to the anchoring disc; and the posterior part is a rounded body (sack), about one-quarter of the spore length. Spores do not appear to cluster together as a group. Each spore is surrounded by a sporophorous membrane closely adjacent to the exospore layer. A phylogenetic analysis of SSU rDNA sequences by different methods placed E. binucleata n. sp. in a clade with representatives of the microsporidian genera Cystosporogenes and Vittaforma. Observations of microsporidia in several other ciliates are discussed in view of the microsporidian infection frequency in the phylum Ciliophora. [source]

An Analysis of the Microsporidian Genus Brachiola, with Comparisons of Human and Insect Isolates of Brachiola algerae

THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 6 2004
ANN CALI
ABSTRACT 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. [source]

Identification of a New Microsporidian Parasite Related to Vittaforma corneae in HIV-Positive and HIV-Negative Patients from Portugal

THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2003
IRSHAD M. SULAIMAN
ABSTRACT. Fecal samples from 22 HIV-positive and 3 HIV-negative patients from Portugal with symptomatic diarrhea were diagnosed positive for microsporidia by microscopy, with most parasites detected significantly bigger than Enterocytozoon bieneusi and Encephalitozoon spp. Sequence characterization of the small subunit (SSU) rRNA gene identified a microsporidian parasite with 96% homology to two published Vittaforma corneae sequences. Phylogenetic analysis confirmed the genetic relatedness of this new microsporidian parasite to Vittaforma corneae as well as Cystosporogenes operophterae. Results of the study demonstrate the presence of a new human-pathogenic microsporidian species, which is responsible for significant number of infections in HIV-positive and HIV-negative patients in Portugal. [source]