{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,12]],"date-time":"2026-10-12T18:29:31Z","timestamp":1791829771176,"version":"4.3.4"},"reference-count":60,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2016,4,15]],"date-time":"2016-04-15T00:00:00Z","timestamp":1460678400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2016,4,15]],"date-time":"2016-04-15T00:00:00Z","timestamp":1460678400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sci Rep"],"abstract":"<jats:title>Abstract<\/jats:title><jats:p><jats:italic>Legionella pneumophila<\/jats:italic>, the causative agent of Legionnaires\u2019 disease, replicates within alveolar macrophages and free-living amoebae. However, the lifestyle of <jats:italic>L. pneumophila<\/jats:italic> in the environment remains largely unknown. Here we established a novel natural host model of <jats:italic>L. pneumophila<\/jats:italic> endosymbiosis using the ciliate <jats:italic>Paramecium caudatum<\/jats:italic>. We also identified <jats:italic>Legionella<\/jats:italic> endosymbiosis-modulating factor A (LefA), which contributes to the change in life stage from endosymbiosis to host lysis, enabling escape to the environment. We isolated <jats:italic>L. pneumophila<\/jats:italic> strains from the environment and they exhibited cytotoxicity toward <jats:italic>P. caudatum<\/jats:italic> and induced host lysis. Acidification of the <jats:italic>Legionella<\/jats:italic>-containing vacuole (LCV) was inhibited and enlarged LCVs including numerous bacteria were observed in <jats:italic>P. caudatum<\/jats:italic> infected with <jats:italic>L. pneumophila<\/jats:italic>. An isogenic <jats:italic>L. pneumophila lefA<\/jats:italic> mutant exhibited decreased cytotoxicity toward <jats:italic>P. caudatum<\/jats:italic> and impaired the modification of LCVs, resulting in the establishment of endosymbiosis between them. Our results suggest that <jats:italic>L. pneumophila<\/jats:italic> may have a mechanism to switch their endosymbiosis in protistan hosts in the environment.<\/jats:p>","DOI":"10.1038\/srep24322","type":"journal-article","created":{"date-parts":[[2016,4,15]],"date-time":"2016-04-15T09:17:41Z","timestamp":1460711861000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":43,"title":["Ciliate Paramecium is a natural reservoir of Legionella pneumophila"],"prefix":"10.1038","volume":"6","author":[{"given":"Kenta","family":"Watanabe","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryo","family":"Nakao","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Masahiro","family":"Fujishima","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Masato","family":"Tachibana","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takashi","family":"Shimizu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Masahisa","family":"Watarai","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2016,4,15]]},"reference":[{"key":"BFsrep24322_CR1","doi-asserted-by":"publisher","first-page":"21","DOI":"10.1111\/j.1574-695X.2011.00916.x","volume":"64","author":"M Taylor","year":"2012","unstructured":"Taylor, M., Mediannikov, O., Raoult, D. & Greub, G. Endosymbiotic bacteria associated with nematodes, ticks and amoebae. FEMS Immunol Med Microbiol 64, 21\u201331, doi: 10.1111\/j.1574-695X.2011.00916.x (2012).","journal-title":"FEMS Immunol Med Microbiol"},{"key":"BFsrep24322_CR2","doi-asserted-by":"publisher","first-page":"e95166","DOI":"10.1371\/journal.pone.0095166","volume":"9","author":"K Ishida","year":"2014","unstructured":"Ishida, K. et al. Amoebal endosymbiont Neochlamydia genome sequence illuminates the bacterial role in the defense of the host amoebae against Legionella pneumophila. PLoS One 9, e95166, doi: 10.1371\/journal.pone.0095166 (2014).","journal-title":"PLoS One"},{"key":"BFsrep24322_CR3","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1128\/aem.63.1.115-121.1997","volume":"63","author":"R Amann","year":"1997","unstructured":"Amann, R. et al. Obligate intracellular bacterial parasites of acanthamoebae related to Chlamydia spp. Appl Environ Microbiol 63, 115\u2013121 (1997).","journal-title":"Appl Environ Microbiol"},{"key":"BFsrep24322_CR4","doi-asserted-by":"crossref","unstructured":"Schulz, F. et al. A Rickettsiales Symbiont of Amoebae with Ancient Features. Environ Microbiol, doi: 10.1111\/1462-2920.12881 (2015).","DOI":"10.1111\/1462-2920.12881"},{"key":"BFsrep24322_CR5","doi-asserted-by":"crossref","first-page":"422","DOI":"10.1128\/aem.51.2.422-424.1986","volume":"51","author":"JM Barbaree","year":"1986","unstructured":"Barbaree, J. M., Fields, B. S., Feeley, J. C., Gorman, G. W. & Martin, W. T. Isolation of protozoa from water associated with a legionellosis outbreak and demonstration of intracellular multiplication of Legionella pneumophila. Appl Environ Microbiol 51, 422\u2013424 (1986).","journal-title":"Appl Environ Microbiol"},{"key":"BFsrep24322_CR6","doi-asserted-by":"publisher","first-page":"355","DOI":"10.1016\/s1387-2656(05)11011-4","volume":"11","author":"P Borella","year":"2005","unstructured":"Borella, P., Guerrieri, E., Marchesi, I., Bondi, M. & Messi, P. Water ecology of Legionella and protozoan: environmental and public health perspectives. Biotechnol Annu Rev 11, 355\u2013380, doi: 10.1016\/s1387-2656(05)11011-4 (2005).","journal-title":"Biotechnol Annu Rev"},{"key":"BFsrep24322_CR7","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1128\/iai.53.3.553-559.1986","volume":"53","author":"BS Fields","year":"1986","unstructured":"Fields, B. S. et al. Comparison of guinea pig and protozoan models for determining virulence of Legionella species. Infect Immun 53, 553\u2013559 (1986).","journal-title":"Infect Immun"},{"key":"BFsrep24322_CR8","doi-asserted-by":"publisher","first-page":"823","DOI":"10.1097\/01.ccm.0000201878.51343.f1","volume":"34","author":"L Fenner","year":"2006","unstructured":"Fenner, L. et al. Are clinical isolates of Pseudomonas aeruginosa more virulent than hospital environmental isolates in amebal co-culture test? Crit Care Med 34, 823\u2013828, doi: 10.1097\/01.ccm.0000201878.51343.f1 (2006).","journal-title":"Crit Care Med"},{"key":"BFsrep24322_CR9","doi-asserted-by":"publisher","first-page":"393","DOI":"10.1016\/j.resmic.2007.01.003","volume":"158","author":"G Goy","year":"2007","unstructured":"Goy, G. et al. The Neff strain of Acanthamoeba castellanii, a tool for testing the virulence of Mycobacterium kansasii. Res Microbiol 158, 393\u2013397, doi: 10.1016\/j.resmic.2007.01.003 (2007).","journal-title":"Res Microbiol"},{"key":"BFsrep24322_CR10","doi-asserted-by":"publisher","first-page":"1921","DOI":"10.1098\/rspb.2007.0245","volume":"274","author":"KM Steinberg","year":"2007","unstructured":"Steinberg, K. M. & Levin, B. R. Grazing protozoa and the evolution of the Escherichia coli O157:H7 Shiga toxin-encoding prophage. Proc Biol Sci 274, 1921\u20131929, doi: 10.1098\/rspb.2007.0245 (2007).","journal-title":"Proc Biol Sci"},{"key":"BFsrep24322_CR11","doi-asserted-by":"publisher","first-page":"413","DOI":"10.1128\/CMR.17.2.413-433.2004","volume":"17","author":"G Greub","year":"2004","unstructured":"Greub, G. & Raoult, D. Microorganisms resistant to free-living amoebae. Clin Microbiol Rev 17, 413\u2013433 (2004).","journal-title":"Clin Microbiol Rev"},{"key":"BFsrep24322_CR12","doi-asserted-by":"publisher","first-page":"20","DOI":"10.1128\/aem.71.1.20-28.2005","volume":"71","author":"M Molmeret","year":"2005","unstructured":"Molmeret, M., Horn, M., Wagner, M., Santic, M. & Abu Kwaik, Y. Amoebae as training grounds for intracellular bacterial pathogens. Appl Environ Microbiol 71, 20\u201328, doi: 10.1128\/aem.71.1.20-28.2005 (2005).","journal-title":"Appl Environ Microbiol"},{"key":"BFsrep24322_CR13","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/S0011-5029(80)80010-1","volume":"27","author":"KN Shands","year":"1980","unstructured":"Shands, K. N. & Fraser, D. W. Legionnaires\u2019 disease. Dis Mon 27, 1\u201359 (1980).","journal-title":"Dis Mon"},{"key":"BFsrep24322_CR14","doi-asserted-by":"publisher","first-page":"1197","DOI":"10.1056\/nejm197712012972202","volume":"297","author":"JE McDade","year":"1977","unstructured":"McDade, J. E. et al. Legionnaires\u2019 disease: isolation of a bacterium and demonstration of its role in other respiratory disease. N Engl J Med 297, 1197\u20131203, doi: 10.1056\/nejm197712012972202 (1977).","journal-title":"N Engl J Med"},{"key":"BFsrep24322_CR15","doi-asserted-by":"publisher","first-page":"9607","DOI":"10.1073\/pnas.89.20.9607","volume":"89","author":"A Marra","year":"1992","unstructured":"Marra, A., Blander, S. J., Horwitz, M. A. & Shuman, H. A. Identification of a Legionella pneumophila locus required for intracellular multiplication in human macrophages. Proc Natl Acad Sci USA 89, 9607\u20139611 (1992).","journal-title":"Proc Natl Acad Sci USA"},{"key":"BFsrep24322_CR16","doi-asserted-by":"publisher","first-page":"7","DOI":"10.1111\/j.1365-2958.1993.tb01092.x","volume":"7","author":"KH Berger","year":"1993","unstructured":"Berger, K. H. & Isberg, R. R. Two distinct defects in intracellular growth complemented by a single genetic locus in Legionella pneumophila. Mol Microbiol 7, 7\u201319 (1993).","journal-title":"Mol Microbiol"},{"key":"BFsrep24322_CR17","doi-asserted-by":"crossref","first-page":"5361","DOI":"10.1128\/iai.61.12.5361-5373.1993","volume":"61","author":"AB Sadosky","year":"1993","unstructured":"Sadosky, A. B., Wiater, L. A. & Shuman, H. A. Identification of Legionella pneumophila genes required for growth within and killing of human macrophages. Infect Immun 61, 5361\u20135373 (1993).","journal-title":"Infect Immun"},{"key":"BFsrep24322_CR18","doi-asserted-by":"publisher","first-page":"663","DOI":"10.1046\/j.1365-2958.1998.00841.x","volume":"28","author":"CR Roy","year":"1998","unstructured":"Roy, C. R., Berger, K. H. & Isberg, R. R. Legionella pneumophila DotA protein is required for early phagosome trafficking decisions that occur within minutes of bacterial uptake. Mol Microbiol 28, 663\u2013674 (1998).","journal-title":"Mol Microbiol"},{"key":"BFsrep24322_CR19","doi-asserted-by":"publisher","first-page":"281","DOI":"10.1111\/j.1574-6976.2010.00209.x","volume":"34","author":"C Moliner","year":"2010","unstructured":"Moliner, C., Fournier, P. E. & Raoult, D. Genome analysis of microorganisms living in amoebae reveals a melting pot of evolution. FEMS Microbiol Rev 34, 281\u2013294, doi: 10.1111\/j.1574-6976.2010.00209.x (2010).","journal-title":"FEMS Microbiol Rev"},{"key":"BFsrep24322_CR20","doi-asserted-by":"publisher","first-page":"299","DOI":"10.1016\/j.tim.2012.03.005","volume":"20","author":"T Al-Quadan","year":"2012","unstructured":"Al-Quadan, T., Price, C. T. & Abu Kwaik, Y. Exploitation of evolutionarily conserved amoeba and mammalian processes by Legionella. Trends Microbiol 20, 299\u2013306, doi: 10.1016\/j.tim.2012.03.005 (2012).","journal-title":"Trends Microbiol"},{"key":"BFsrep24322_CR21","doi-asserted-by":"publisher","first-page":"514395","DOI":"10.1155\/2013\/514395","volume":"2013","author":"M Tachibana","year":"2013","unstructured":"Tachibana, M., Nakamoto, M., Kimura, Y., Shimizu, T. & Watarai, M. Characterization of Legionella pneumophila isolated from environmental water and ashiyu foot spa. Biomed Res Int 2013, 514395, doi: 10.1155\/2013\/514395 (2013).","journal-title":"Biomed Res Int"},{"key":"BFsrep24322_CR22","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1128\/aem.41.1.9-16.1981","volume":"41","author":"CB Fliermans","year":"1981","unstructured":"Fliermans, C. B. et al. Ecological distribution of Legionella pneumophila. Appl Environ Microbiol 41, 9\u201316 (1981).","journal-title":"Appl Environ Microbiol"},{"key":"BFsrep24322_CR23","doi-asserted-by":"publisher","first-page":"1179","DOI":"10.1136\/jcp.33.12.1179","volume":"33","author":"TJ Rowbotham","year":"1980","unstructured":"Rowbotham, T. J. Preliminary report on the pathogenicity of Legionella pneumophila for freshwater and soil amoebae. J Clin Pathol 33, 1179\u20131183 (1980).","journal-title":"J Clin Pathol"},{"key":"BFsrep24322_CR24","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1128\/aem.47.3.467-471.1984","volume":"47","author":"BS Fields","year":"1984","unstructured":"Fields, B. S., Shotts, E. B. Jr., Feeley, J. C., Gorman, G. W. & Martin, W. T. Proliferation of Legionella pneumophila as an intracellular parasite of the ciliated protozoan Tetrahymena pyriformis. Appl Environ Microbiol 47, 467\u2013471 (1984).","journal-title":"Appl Environ Microbiol"},{"key":"BFsrep24322_CR25","doi-asserted-by":"publisher","first-page":"383","DOI":"10.1080\/00365549950163833","volume":"31","author":"J Winiecka-Krusnell","year":"1999","unstructured":"Winiecka-Krusnell, J. & Linder, E. Free-living amoebae protecting Legionella in water: the tip of an iceberg? Scand J Infect Dis 31, 383\u2013385 (1999).","journal-title":"Scand J Infect Dis"},{"key":"BFsrep24322_CR26","doi-asserted-by":"publisher","first-page":"19","DOI":"10.1111\/j.1462-5822.2011.01713.x","volume":"14","author":"ZQ Luo","year":"2012","unstructured":"Luo, Z. Q. Legionella secreted effectors and innate immune responses. Cell Microbiol 14, 19\u201327, doi: 10.1111\/j.1462-5822.2011.01713.x (2012).","journal-title":"Cell Microbiol"},{"key":"BFsrep24322_CR27","doi-asserted-by":"publisher","first-page":"274","DOI":"10.1128\/cmr.00052-09","volume":"23","author":"HJ Newton","year":"2010","unstructured":"Newton, H. J., Ang, D. K., van Driel, I. R. & Hartland, E. L. Molecular pathogenesis of infections caused by Legionella pneumophila. Clin Microbiol Rev 23, 274\u2013298, doi: 10.1128\/cmr.00052-09 (2010).","journal-title":"Clin Microbiol Rev"},{"key":"BFsrep24322_CR28","doi-asserted-by":"crossref","unstructured":"Richards, A. M., Von Dwingelo, J. E., Price, C. T. & Abu Kwaik, Y. Cellular microbiology and molecular ecology of Legionella-amoeba interaction. Virulence 4, 307\u2013314, doi: 10.4161\/viru.24290 (2013).","DOI":"10.4161\/viru.24290"},{"key":"BFsrep24322_CR29","doi-asserted-by":"publisher","first-page":"286","DOI":"10.1016\/0966-842X(96)10041-X","volume":"4","author":"BS Fields","year":"1996","unstructured":"Fields, B. S. The molecular ecology of legionellae. Trends Microbiol 4, 286\u2013290 (1996).","journal-title":"Trends Microbiol"},{"key":"BFsrep24322_CR30","doi-asserted-by":"crossref","unstructured":"Wichterman, R. The Biology of Paramecium. Plenum Press (1986).","DOI":"10.1007\/978-1-4757-0372-6"},{"key":"BFsrep24322_CR31","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1083\/jcb.96.1.1","volume":"96","author":"RM Steinman","year":"1983","unstructured":"Steinman, R. M., Mellman, I. S., Muller, W. A. & Cohn, Z. A. Endocytosis and the recycling of plasma membrane. J Cell Biol 96, 1\u201327 (1983).","journal-title":"J Cell Biol"},{"key":"BFsrep24322_CR32","doi-asserted-by":"publisher","first-page":"79","DOI":"10.1016\/s1937-6448(10)80003-6","volume":"280","author":"H Plattner","year":"2010","unstructured":"Plattner, H. Membrane trafficking in protozoa SNARE proteins, H+-ATPase, actin and other key players in ciliates. Int Rev Cell Mol Biol 280, 79\u2013184, doi: 10.1016\/s1937-6448(10)80003-6 (2010).","journal-title":"Int Rev Cell Mol Biol"},{"key":"BFsrep24322_CR33","doi-asserted-by":"publisher","first-page":"201","DOI":"10.1007\/978-3-540-92677-1_8","volume":"12","author":"M Fujishima","year":"2009","unstructured":"Fujishima, M. Infection and Maintenance of Holospora Species in Paramecium caudatum. Microbiology Monographs 12, 201\u2013225 (2009).","journal-title":"Microbiology Monographs"},{"key":"BFsrep24322_CR34","doi-asserted-by":"publisher","first-page":"124","DOI":"10.1016\/j.ejop.2011.10.002","volume":"48","author":"M Fujishima","year":"2012","unstructured":"Fujishima, M. & Kodama, Y. Endosymbionts in paramecium. Eur J Protistol 48, 124\u2013137, doi: 10.1016\/j.ejop.2011.10.002 (2012).","journal-title":"Eur J Protistol"},{"key":"BFsrep24322_CR35","doi-asserted-by":"publisher","first-page":"33","DOI":"10.1016\/s1937-6448(10)79002-x","volume":"279","author":"Y Kodama","year":"2010","unstructured":"Kodama, Y. & Fujishima, M. Secondary symbiosis between Paramecium and Chlorella cells. Int Rev Cell Mol Biol 279, 33\u201377, doi: 10.1016\/s1937-6448(10)79002-x (2010).","journal-title":"Cell Mol Biol"},{"key":"BFsrep24322_CR36","doi-asserted-by":"publisher","first-page":"19","DOI":"10.1016\/S0932-4739(96)80072-1","volume":"32","author":"SI Fokin","year":"1996","unstructured":"Fokin, S. I., Brigge, T., Brenner, J. & G\u00f6rtz, H. D. Holospora species infected the nuclei of Paramecium appear to belong into two groups of bacteria. Eur. J. Protistol 32, 19\u201324 (1996).","journal-title":"Eur. J. Protistol"},{"key":"BFsrep24322_CR37","first-page":"175","volume":"276","author":"AO Smurov","year":"1998","unstructured":"Smurov, A. O. & Fokin, S. I. Resistance of Paramecium caudatum infected with endonuclear bacteria Holospora against salinity impact. Proc Zool Ins RAS 276, 175\u2013178 (1998).","journal-title":"Proc Zool Ins RAS"},{"key":"BFsrep24322_CR38","doi-asserted-by":"publisher","first-page":"293","DOI":"10.1111\/j.1550-7408.2003.tb00137.x","volume":"50","author":"M Hori","year":"2003","unstructured":"Hori, M. & Fujishima, M. The endosymbiotic bacterium Holospora obtusa enhances heat-shock gene expression of the host Paramecium caudatum. J Eukaryot Microbiol 50, 293\u2013298 (2003).","journal-title":"J Eukaryot Microbiol"},{"key":"BFsrep24322_CR39","doi-asserted-by":"publisher","first-page":"101","DOI":"10.1016\/j.femsle.2004.11.053","volume":"243","author":"M Fujishima","year":"2005","unstructured":"Fujishima, M., Kawai, M. & Yamamoto, R. Paramecium caudatum acquires heat-shock resistance in ciliary movement by infection with the endonuclear symbiotic bacterium Holospora obtusa. FEMS Microbiol Lett 243, 101\u2013105, doi: 10.1016\/j.femsle.2004.11.053 (2005).","journal-title":"FEMS Microbiol Lett"},{"key":"BFsrep24322_CR40","doi-asserted-by":"publisher","first-page":"515","DOI":"10.1111\/j.1550-7408.2008.00352.x","volume":"55","author":"M Hori","year":"2008","unstructured":"Hori, M., Fujii, K. & Fujishima, M. Micronucleus-specific bacterium Holospora elegans irreversibly enhances stress gene expression of the host Paramecium caudatum. J Eukaryot Microbiol 55, 515\u2013521, doi: 10.1111\/j.1550-7408.2008.00352.x (2008).","journal-title":"J Eukaryot Microbiol"},{"key":"BFsrep24322_CR41","doi-asserted-by":"publisher","first-page":"131","DOI":"10.1007\/978-3-540-92677-1_6","volume":"12","author":"HD G\u00f6rtz","year":"2009","unstructured":"G\u00f6rtz, H. D. & Fokin, S. I. Diversity of Endosymbiotic Bacteria in Paramecium. Microbiology Monographs 12, 131\u2013160 (2009).","journal-title":"Microbiology Monographs"},{"key":"BFsrep24322_CR42","doi-asserted-by":"publisher","first-page":"277","DOI":"10.1016\/S0074-7696(00)98007-0","volume":"198","author":"RD Allen","year":"2000","unstructured":"Allen, R. D. & Fok, A. K. Membrane trafficking and processing in Paramecium. Int Rev Cytol 198, 277\u2013318 (2000).","journal-title":"Int Rev Cytol"},{"key":"BFsrep24322_CR43","doi-asserted-by":"crossref","unstructured":"Fujishima, M. & Kawai, M. Acidification in Digestive Vacuoles is an Early Event Required for Holospora Infection of Paramecium Nucleus. Eukaryotism and Symbiosis 367\u2013370 (1997).","DOI":"10.1007\/978-3-642-60885-8_28"},{"key":"BFsrep24322_CR44","doi-asserted-by":"publisher","first-page":"15","DOI":"10.1111\/cmi.12235","volume":"16","author":"C Hoffmann","year":"2014","unstructured":"Hoffmann, C., Harrison, C. F. & Hilbi, H. The natural alternative: protozoa as cellular models for Legionella infection. Cell Microbiol 16, 15\u201326, doi: 10.1111\/cmi.12235 (2014).","journal-title":"Cell Microbiol"},{"key":"BFsrep24322_CR45","doi-asserted-by":"publisher","first-page":"1435","DOI":"10.1111\/j.1462-5822.2009.01351.x","volume":"11","author":"IS Franco","year":"2009","unstructured":"Franco, I. S., Shuman, H. A. & Charpentier, X. The perplexing functions and surprising origins of Legionella pneumophila type IV secretion effectors. Cell Microbiol 11, 1435\u20131443, doi: 10.1111\/j.1462-5822.2009.01351.x (2009).","journal-title":"Cell Microbiol"},{"key":"BFsrep24322_CR46","doi-asserted-by":"publisher","first-page":"5188","DOI":"10.1073\/pnas.89.11.5188","volume":"89","author":"NP Cianciotto","year":"1992","unstructured":"Cianciotto, N. P. & Fields, B. S. Legionella pneumophila mip gene potentiates intracellular infection of protozoa and human macrophages. Proc Natl Acad Sci USA 89, 5188\u20135191 (1992).","journal-title":"Proc Natl Acad Sci USA"},{"key":"BFsrep24322_CR47","doi-asserted-by":"publisher","first-page":"2187","DOI":"10.1128\/aem.01214-07","volume":"74","author":"SG Berk","year":"2008","unstructured":"Berk, S. G. et al. Packaging of live Legionella pneumophila into pellets expelled by Tetrahymena spp. does not require bacterial replication and depends on a Dot\/Icm-mediated survival mechanism. Appl Environ Microbiol 74, 2187\u20132199, doi: 10.1128\/aem.01214-07 (2008).","journal-title":"Appl Environ Microbiol"},{"key":"BFsrep24322_CR48","doi-asserted-by":"crossref","first-page":"457","DOI":"10.1242\/jeb.196.1.457","volume":"196","author":"TA Krulwich","year":"1994","unstructured":"Krulwich, T. A., Cheng, J. & Guffanti, A. A. The role of monovalent cation\/proton antiporters in Na(+)-resistance and pH homeostasis in Bacillus: an alkaliphile versus a neutralophile. J Exp Biol 196, 457\u2013470 (1994).","journal-title":"J Exp Biol"},{"key":"BFsrep24322_CR49","doi-asserted-by":"publisher","first-page":"144","DOI":"10.1016\/S0005-2728(00)00284-X","volume":"1505","author":"E Padan","year":"2001","unstructured":"Padan, E., Venturi, M., Gerchman, Y. & Dover, N. Na(+)\/H(+) antiporters. Biochim Biophys Acta 1505, 144\u2013157 (2001).","journal-title":"Biochim Biophys Acta"},{"key":"BFsrep24322_CR50","doi-asserted-by":"publisher","first-page":"231","DOI":"10.1016\/S0005-2728(97)00102-3","volume":"1363","author":"T Sakuma","year":"1998","unstructured":"Sakuma, T., Yamada, N., Saito, H., Kakegawa, T. & Kobayashi, H. pH dependence of the function of sodium ion extrusion systems in Escherichia coli. Biochim Biophys Acta 1363, 231\u2013237 (1998).","journal-title":"Biochim Biophys Acta"},{"key":"BFsrep24322_CR51","doi-asserted-by":"publisher","first-page":"3527","DOI":"10.1038\/srep03527","volume":"3","author":"G Khare","year":"2013","unstructured":"Khare, G., Reddy, P. V., Sidhwani, P. & Tyagi, A. K. KefB inhibits phagosomal acidification but its role is unrelated to M. tuberculosis survival in host. Sci Rep 3, 3527, doi: 10.1038\/srep03527 (2013).","journal-title":"Sci Rep"},{"key":"BFsrep24322_CR52","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1007\/82_2013_351","volume":"376","author":"P Escoll","year":"2013","unstructured":"Escoll, P., Rolando, M., Gomez-Valero, L. & Buchrieser, C. From amoeba to macrophages: exploring the molecular mechanisms of Legionella pneumophila infection in both hosts. Curr Top Microbiol Immunol 376, 1\u201334, doi: 10.1007\/82_2013_351 (2013).","journal-title":"Curr Top Microbiol Immunol"},{"key":"BFsrep24322_CR53","doi-asserted-by":"crossref","first-page":"5057","DOI":"10.1128\/iai.65.12.5057-5066.1997","volume":"65","author":"G Segal","year":"1997","unstructured":"Segal, G. & Shuman, H. A. Characterization of a new region required for macrophage killing by Legionella pneumophila. Infect Immun 65, 5057\u20135066 (1997).","journal-title":"Infect Immun"},{"key":"BFsrep24322_CR54","doi-asserted-by":"publisher","first-page":"873","DOI":"10.1126\/science.279.5352.873","volume":"279","author":"JP Vogel","year":"1998","unstructured":"Vogel, J. P., Andrews, H. L., Wong, S. K. & Isberg, R. R. Conjugative transfer by the virulence system of Legionella pneumophila. Science 279, 873\u2013876 (1998).","journal-title":"Science"},{"key":"BFsrep24322_CR55","doi-asserted-by":"publisher","first-page":"171","DOI":"10.2307\/1536748","volume":"41","author":"LL Woodruff","year":"1921","unstructured":"Woodruff, L. L. The Structure, Life History and Intrageneric Relationships of Paramecium calkinsi, sp. nov. Biological Bulletin 41, 171\u2013180, doi: 10.2307\/1536748 (1921).","journal-title":"Biological Bulletin"},{"key":"BFsrep24322_CR56","first-page":"285","volume":"10","author":"AW Jankowski","year":"1972","unstructured":"Jankowski, A. W. Cytogenetic of Paramecium putrunum C. et L., (1958). Acta Protozool 10, 285\u2013394 (1972).","journal-title":"Acta Protozool"},{"key":"BFsrep24322_CR57","doi-asserted-by":"crossref","unstructured":"Watanabe, K., Suzuki, H., Nakao, R., Shimizu, T. & Watarai, M. Draft Genome Sequences of Five Legionella pneumophila Strains Isolated from Environmental Water Samples. Genome Announc 3, doi: 10.1128\/genomeA.00474-15 (2015).","DOI":"10.1128\/genomeA.00474-15"},{"key":"BFsrep24322_CR58","doi-asserted-by":"publisher","first-page":"123","DOI":"10.1111\/j.1550-7408.1990.tb05881.x","volume":"37","author":"M Fujishima","year":"1990","unstructured":"Fujishima, M., Sawabe, H. & Iwatsuki, K. Scanning electron microscopic observation of differentiation from the reproductive short form to the infectious long form of Holospora obtusa. J. Protozool 37, 123\u2013128 (1990).","journal-title":"J. Protozool"},{"key":"BFsrep24322_CR59","unstructured":"Dryl, S. Antigenic transformation in Paramecium aurelia after homologous antiserum treatment during autogamy and conjugation. J. Protozool 6 (1959)."},{"key":"BFsrep24322_CR60","doi-asserted-by":"publisher","first-page":"1081","DOI":"10.1084\/jem.194.8.1081","volume":"194","author":"M Watarai","year":"2001","unstructured":"Watarai, M. et al. Legionella pneumophila is internalized by a macropinocytotic uptake pathway controlled by the Dot\/Icm system and the mouse Lgn1 locus. J Exp Med 194, 1081\u20131096 (2001).","journal-title":"J Exp Med"}],"container-title":["Scientific Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/srep24322","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/srep24322.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/srep24322.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,1,4]],"date-time":"2023-01-04T18:30:46Z","timestamp":1672857046000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/srep24322"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,4,15]]},"references-count":60,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2016,7,26]]}},"alternative-id":["BFsrep24322"],"URL":"https:\/\/doi.org\/10.1038\/srep24322","relation":{},"ISSN":["2045-2322"],"issn-type":[{"value":"2045-2322","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,4,15]]},"assertion":[{"value":"12 October 2015","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"24 March 2016","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"15 April 2016","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"The authors declare no competing financial interests.","order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"24322"}}