biostudies-literatureUnknown11Solbach MDLegionellales-infected water is a frequent cause of local outbreaks of Legionnaires' disease and Pontiac fever. Decontaminations are difficult because Legionellales reproduce in eukaryotic microorganisms (protists). Most often, Legionellales have been isolated from amoebae; however, the culture-based sampling methods are taxonomically biased. Sequencing studies show that amoebae in the cercozoan class Thecofilosea are dominant in soils and wastewater treatment plants, prompting us to screen their capability to serve as potential hosts of endosymbiotic bacteria. Environmental isolates of Thecofilosea contained a surprising richness of endosymbiotic Legionellales, including <i>Legionella</i>. Considering the widespread dispersal of Legionellales in apparently unrelated amoeboid protist taxa,Frontiers in cellular and infection microbiology642216https://www.ebi.ac.uk/biostudies/studies/S-EPMC7982676biostudies-literatureNovel Endosymbionts in Rhizarian Amoebae Imply Universal Infection of Unrelated Free-Living Amoebae by Legionellales.PMC7982676Bonkowski MSolbach MDDumack KfalseNovel Endosymbionts in Rhizarian Amoebae Imply Universal Infection of Unrelated Free-Living Amoebae by Legionellales.Legionellales-infected water is a frequent cause of local outbreaks of Legionnaires' disease and Pontiac fever. Decontaminations are difficult because Legionellales reproduce in eukaryotic microorganisms (protists). Most often, Legionellales have been isolated from amoebae; however, the culture-based sampling methods are taxonomically biased. Sequencing studies show that amoebae in the cercozoan class Thecofilosea are dominant in soils and wastewater treatment plants, prompting us to screen their capability to serve as potential hosts of endosymbiotic bacteria. Environmental isolates of Thecofilosea contained a surprising richness of endosymbiotic Legionellales, including <i>Legionella</i>. Considering the widespread dispersal of Legionellales in apparently unrelated amoeboid protist taxa,2021-01-01T00:00:00Z20212025-04-22T10:49:38.244Z2025-04-05T23:39:36.045ZS-EPMC79826763376338910.3389/fcimb.2021.642216