The first case of microsporidiosis inParamecium

Abstract

A new microsporidian species, Globosporidium paramecii gen. nov., sp. nov., from Paramecium primaurelia is described on the basis of morphology, fine structure, and SSU rRNA gene sequence. This is the first case of microsporidiosis in Paramecium reported so far. All observed stages of the life cycle are monokaryotic. The parasites develop in the cytoplasm, at least some part of the population in endoplasmic reticulum and its derivates. Meronts divide by binary fission. Sporogonial plasmodium divides by rosette-like budding. Early sporoblasts demonstrate a well-developed exospore forming blister-like structures. Spores with distinctive spherical shape are dimorphic in size (3.7 ± 0.2 and 1.9 ± 0.2 μm). Both types of spores are characterized by a thin endospore, a short isofilar polar tube making one incomplete coil, a bipartite polaroplast, and a large posterior vacuole. Experimental infection was successful for 5 of 10 tested strains of the Paramecium aurelia species complex. All susceptible strains belong to closely related P. primaurelia and P. pentaurelia species. Phylogenetic analysis placed the new species in the Clade 4 of Microsporidia and revealed its close relationship to Euplotespora binucleata (a microsporidium from the ciliate Euplotes woodruffi), to Helmichia lacustris and Mrazekia macrocyclopis, microsporidia from aquatic invertebrates.

A phylogenetic framework to investigate the microsporidian communities through metabarcoding and its application to lake ecosystems

“…As our analysis focused on small sized fractions (< 150 μm), this novel diversity may correspond at least partly to not yet described microsporidian species infecting small hosts. Some studies report infections of ciliates and rotifers by Microsporidia in freshwater environments (Fokin et al ., 2008; Wolska and Mazurkiewicz‐Zapalowicz, 2013; Stentiford et al ., 2013a; Yakovleva et al ., 2020), but only two sequences from ciliates, and none from rotifers are currently available in the databases. Further sampling efforts aiming to identify host‐microsporidian interactions in these small size organisms will be necessary in order to confirm this hypothesis.…”

Generation of a microsporidia species attribute database and analysis of the extensive ecological and phenotypic diversity of microsporidia

“…Although very closely related microsporidia almost always infect the same phylum, we observed 28 pairs of species with greater than 80% similarity infecting different phyla (Table S5C). This data includes known examples of highly similar species infecting different phyla such as between microsporidia that infect ciliates and those that infect aquatic arthropods and between microsporidia infecting aquatic crustaceans and those infecting parasitic trematodes and paramyxids (47,48). The species pairs we identified also included eight such instances between species that infect arthropods and the known human infecting species Vittaforma corneae and Trachipleistophora hominis (26).…”

Temporal variations of Microsporidia diversity and discovery of new host–parasite interactions in a lake ecosystem

“…Mikhailov et al ., 2016). In freshwater ecosystems, infections by Microsporidia have been registered in ciliates (Lutz and Splendore, 1908; Krüger, 1956; Görtz, 1987; Fokin et al ., 2008; Yakovleva et al ., 2020), gregarines (Codreanu‐Bălcescu and Codreanu, 1976; Rühl and Korn, 1979), unicellular cnidarians (Morris and Freeman, 2010) and rotifers (Gorbunov and Kosova, 2001; Wolska and Mazurkiewicz‐Zapalowicz, 2013). Most of these observations are based on light microscopy and/or transmission electron microscopy therefore allowing only morphological descriptions.…”