Protosteloid Amoebae (Protosteliida, Protosporangiida, Cavosteliida, Schizoplasmodiida, Fractoviteliida, and Sporocarpic Members of Vannellida, Centramoebida, and Pellitida)

Spiegel, Frederick W.; Shadwick, Lora L.; Ndiritu, George G.; Brown, Matthew W.; Aguilar, María José Cuesta; Shadwick, John D.

doi:10.1007/978-3-319-28149-0_12

Cited by 11 publications

(13 citation statements)

References 56 publications

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“…Amoebae are predominant environmental micro-predators, but only a few of them have been described to actively feed on fungi (Chakraborty et al, 1983;Old, 1977;Old & Darbyshire, 1978). Such a fungivorous lifestyle has been described for Protostelium mycophagum, the type species for the polyphyletic group of protosteloid amoebae that form microscopic, stalked fruiting bodies from single cells and are found on nearly all continents (Kang et al, 2017;Shadwick et al, 2018;Spiegel et al, 2017). We have recently isolated and characterized a strain of P. aurantium (formerly known as Planoprotostelium aurantium), which was found to selectively recognise, kill and feed on a wide range of ascomycete and basidiomycete yeasts, including major human pathogens of the Candida clade (Radosa et al, 2019).…”

Section: Discussionmentioning

confidence: 99%

The fungivorous amoeba Protostelium aurantium targets redox homeostasis and cell wall integrity during intracellular killing of Candida parapsilosis

Radosa

Sprague

Lau

et al. 2021

Cellular Microbiology

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Predatory interactions among microbes are major evolutionary driving forces for biodiversity. The fungivorous amoeba Protostelium aurantium has a wide fungal food spectrum including foremost pathogenic members of the genus Candida. Here we show that upon phagocytic ingestion by the amoeba, Candida parapsilosis is confronted with an oxidative burst and undergoes lysis within minutes of processing in acidified phagolysosomes. On the fungal side, a functional genomic approach identified copper and redox homeostasis as primary targets of amoeba predation, with the highly expressed copper exporter gene CRP1 and the peroxiredoxin gene PRX1 contributing to survival when encountered with P. aurantium. The fungicidal activity was largely retained in intracellular vesicles of the amoebae. Following their isolation, the content of these vesicles induced immediate killing and lysis of C. parapsilosis in vitro.Proteomic analysis identified 56 vesicular proteins from P. aurantium. Although completely unknown proteins were dominant, many of them could be categorised as hydrolytic enzymes targeting the fungal cell wall, indicating that fungal cell wall structures are under selection pressure by predatory phagocytes in natural environments. Take Away• The amoeba Protostelium aurantium feeds on fungi, such as Candida parapsilosis.• Ingested yeast cells are exposed to reactive oxygen species.• A copper exporter and a peroxiredoxin contribute to fungal defence.

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Section: Discussionmentioning

confidence: 99%

The fungivorous amoeba Protostelium aurantium targets redox homeostasis and cell wall integrity during intracellular killing of Candida parapsilosis

Radosa

Sprague

Lau

et al. 2021

Cellular Microbiology

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“…fungivorum due to the rapid consumption of the yeast R. mucilaginosa (Hillmann et al, ). In general, protosteloid amoebae are widely distributed across the phylogenetic tree of the Amoebozoa (Shadwick et al, ; Kang et al, ; Spiegel et al, ). Protostelium aurantium (formerly known as Planoprotostelium aurantium ) is part of the P. mycophagum (‘ fungus eating ’) clade whose members are true cosmopolitans and have been recovered from all continents except Antarctica (Aguilar et al, ; Ndiritu et al, ; Hillmann et al, ; Shadwick et al, ).…”

Section: Discussionmentioning

confidence: 99%

The different morphologies of yeast and filamentous fungi trigger distinct killing and feeding mechanisms in a fungivorous amoeba

Radosa

Ferling

Sprague

et al. 2019

Environmental Microbiology

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Summary Size and diverse morphologies pose a primary challenge for phagocytes such as innate immune cells and predatory amoebae when encountering fungal prey. Although filamentous fungi can escape phagocytic killing by pure physical constraints, unicellular spores and yeasts can mask molecular surface patterns or arrest phagocytic processing. Here, we show that the fungivorous amoeba Protostelium aurantium was able to adjust its killing and feeding mechanisms to these different cell shapes. Yeast‐like fungi from the major fungal groups of basidiomycetes and ascomycetes were readily internalized by phagocytosis, except for the human pathogen Candida albicans whose mannoprotein coat was essential to escape recognition by the amoeba. Dormant spores of the filamentous fungus Aspergillus fumigatus also remained unrecognized, but swelling and the onset of germination induced internalization and intracellular killing by the amoeba. Mature hyphae of A. fumigatus were mostly attacked from the hyphal tip and killed by an actin‐mediated invasion of fungal filaments. Our results demonstrate that predatory pressure imposed by amoebae in natural environments selects for distinct survival strategies in yeast and filamentous fungi but commonly targets the fungal cell wall as a crucial molecular pattern associated to prey and pathogens.

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“…The kinetid structures of swimming stages are diagrammed in Spiegel et al. (), Mikryukov and Mylnikov (), Hibberd (), and Pánek et al. ().…”

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confidence: 99%

Revisions to the Classification, Nomenclature, and Diversity of Eukaryotes

Adl

Bass

Lane

et al. 2019

J Eukaryotic Microbiology

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943

799

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This revision of the classification of eukaryotes follows that of Adl et al., 2012 [ J. Euk. Microbiol . 59(5)] and retains an emphasis on protists. Changes since have improved the resolution of many nodes in phylogenetic analyses. For some clades even families are being clearly resolved. As we had predicted, environmental sampling in the intervening years has massively increased the genetic information at hand. Consequently, we have discovered novel clades, exciting new genera and uncovered a massive species level diversity beyond the morphological species descriptions. Several clades known from environmental samples only have now found their home. Sampling soils, deeper marine waters and the deep sea will continue to fill us with surprises. The main changes in this revision are the confirmation that eukaryotes form at least two domains, the loss of monophyly in the Excavata, robust support for the Haptista and Cryptista. We provide suggested primer sets for DNA sequences from environmental samples that are effective for each clade. We have provided a guide to trophic functional guilds in an appendix, to facilitate the interpretation of environmental samples, and a standardized taxonomic guide for East Asian users.

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Protosteloid Amoebae (Protosteliida, Protosporangiida, Cavosteliida, Schizoplasmodiida, Fractoviteliida, and Sporocarpic Members of Vannellida, Centramoebida, and Pellitida)

Cited by 11 publications

References 56 publications

The fungivorous amoeba Protostelium aurantium targets redox homeostasis and cell wall integrity during intracellular killing of Candida parapsilosis

The fungivorous amoeba Protostelium aurantium targets redox homeostasis and cell wall integrity during intracellular killing of Candida parapsilosis

The different morphologies of yeast and filamentous fungi trigger distinct killing and feeding mechanisms in a fungivorous amoeba

Revisions to the Classification, Nomenclature, and Diversity of Eukaryotes

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