{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T00:37:41Z","timestamp":1774312661175,"version":"3.50.1"},"reference-count":34,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2020,5,24]],"date-time":"2020-05-24T00:00:00Z","timestamp":1590278400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003762","name":"Institut Pasteur","doi-asserted-by":"publisher","award":["ACIP n\u00b0A01-11"],"award-info":[{"award-number":["ACIP n\u00b0A01-11"]}],"id":[{"id":"10.13039\/501100003762","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008530","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["FEDER FED-1-1.4 32932"],"award-info":[{"award-number":["FEDER FED-1-1.4 32932"]}],"id":[{"id":"10.13039\/501100008530","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Detection and quantification of pathogenic free-living amoebae (FLA) in water samples is critical for assessing water quality and for disease management issues. The most probable number (MPN) is commonly used to account for FLA in water. Nevertheless, this requires a high number of water replicates and working volumes, and a consequent number of non-nutrient agar (NNA)-plates seeded with Escherichia coli. Herein, we aimed at optimizing this difficult method, taking also into account key factors such as (i) the counting method, (ii) the delay between sample collection and sample processing, and (iii) the temperature during water sample transportation. To simplify the MPN method, we filtrated 1 \u00d7 1000 and 1 \u00d7 100 mL water samples, and cellulose acetate filters were cut in 10 parts and inverted on NNA-plates overlaid with E. coli. The comparison between the classical and our optimized MPN method showed that the final counts were similar, therefore validating the use of the optimized method. Our results also showed that for thermophilic FLA (such as Naegleria fowleri), water samples can be kept at around +30\u00b0C and processed within 24 h. This improved MPN method is now routinely used in our laboratory to control Naegleria sp. in the water samples in Guadeloupe.<\/jats:p>","DOI":"10.3390\/pathogens9050409","type":"journal-article","created":{"date-parts":[[2020,5,25]],"date-time":"2020-05-25T06:43:40Z","timestamp":1590389020000},"page":"409","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["An Optimized Most Probable Number (MPN) Method to Assess the Number of Thermophilic Free-Living Amoebae (FLA) in Water Samples"],"prefix":"10.3390","volume":"9","author":[{"given":"Mirna","family":"Moussa","sequence":"first","affiliation":[{"name":"Unit\u00e9 TReD-Path (Transmission R\u00e9servoir &amp; Diversit\u00e9 des Pathog\u00e8nes), Institut Pasteur de la Guadeloupe, Les Abymes, 97183 Guadeloupe, France"}]},{"given":"Isabel","family":"Marcelino","sequence":"additional","affiliation":[{"name":"Unit\u00e9 TReD-Path (Transmission R\u00e9servoir &amp; Diversit\u00e9 des Pathog\u00e8nes), Institut Pasteur de la Guadeloupe, Les Abymes, 97183 Guadeloupe, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6961-1753","authenticated-orcid":false,"given":"Vincent","family":"Richard","sequence":"additional","affiliation":[{"name":"Institut Pasteur, 75015 Paris, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0872-2908","authenticated-orcid":false,"given":"J\u00e9r\u00f4me","family":"Guerlott\u00e9","sequence":"additional","affiliation":[{"name":"Institut de Syst\u00e9matique, Evolution, Biodiversit\u00e9 (ISYEB) MNHN, CNRS, Sorbonne Universit\u00e9, EPHE Universit\u00e9 des Antilles, Pointe-\u00e0-Pitre, 97110 Guadeloupe, France"}]},{"given":"Antoine","family":"Talarmin","sequence":"additional","affiliation":[{"name":"Unit\u00e9 TReD-Path (Transmission R\u00e9servoir &amp; Diversit\u00e9 des Pathog\u00e8nes), Institut Pasteur de la Guadeloupe, Les Abymes, 97183 Guadeloupe, France"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"433","DOI":"10.2478\/s11686-014-0266-7","article-title":"Thermophilic potentially pathogenic amoebae isolated from natural water bodies in Poland and their molecular characterization","volume":"59","author":"Adamska","year":"2014","journal-title":"Acta Parasitol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"722","DOI":"10.1128\/aem.55.3.722-732.1989","article-title":"Effect of thermal additions on the density and distribution of thermophilic amoebae and pathogenic Naegleria fowleri in a newly created cooling lake","volume":"55","author":"Tyndall","year":"1989","journal-title":"Appl. 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