POTENTIALLY PATHOGENIC FREE-LIVING AMOEBAE IN SOME FLOOD-AFFECTED AREAS DURING 2011 CHIANG MAI FLOOD

SUMMARY The survey was carried out to investigate the presence of potentially pathogenic free-living amoebae (FLA) during flood in Chiang Mai, Thailand in 2011. From different crisis flood areas, seven water samples were collected and tested for the presence of amoebae using culture and molecular methods. By monoxenic culture, FLA were detected from all samples at 37 °C incubation. The FLA growing at 37 °C were morphologically identified as Acanthamoeba spp., Naegleria spp. and some unidentified amoebae. Only three samples (42.8%), defined as thermotolerant FLA, continued to grow at 42 °C. By molecular methods, two non-thermotolerant FlA were shown to have 99% identity to Acanthamoeba sp. and 98% identity to Hartmannella vermiformis while the two thermotolerant FLA were identified as Echinamoeba exundans (100% identity) and Hartmannella sp. (99% identity). This first report of the occurrence of FLA in water during the flood disaster will provide information to the public to be aware of potentially pathogenic FLA.RESUMO A pesquisa foi feita para investigar a presença de amebas de vida livre (FLA) durante a inundação em Chiang Mai, Tailândia, ano de 2011. A partir de diferentes áreas de inundação sete amostras de água foram coletadas e testadas para a presença de amebas usando métodos moleculares e de cultura. Através da cultura monoxênica, FLA foi detectada em todas as amostras após incubação a 37 °C. As FLA crescendo a 37 °C foram identificadas morfologicamente como Acanthamoeba spp, Naegleria spp e algumas amebas não determinadas. Somente três amostras (42,8%) definidas como FLA termotolerantes continuaram a crescer a 42 °C. Por métodos moleculares duas FLA termotolerantes tiveram 99% de identidade com a Acanthamoeba sp e 98% de identidade com Hartmannella vermiformis enquanto as duas FLA termotolerantes foram identificadas como Echinamoeba exundans (100% de identidade) e Hartmannella sp (99% de identidade). Este primeiro relato da ocorrência de FLA em águas durante inundações informa ao público que ele deve estar atento de FLA potencialmente patogênica

Effect of the depth of fecal suspensions on production of FL.^a

<p>±674.1 (800–2,500) FL.^a Fresh stool produced 1,561.7</p><p>^b Means and standard deviation (range) derived from 6 different stool samples.</p><p>^c Nonparametric Kruskal-Wallis test was analyzed.</p><p>^d Not applicable.</p

Growth and development of <i>S. stercoralis</i> in different containers.^a

<p>^a Total numbers derived from 30 different stool samples.</p><p>%).^b No. (</p

Growth and development of <i>S. stercoralis</i> in stool suspensions kept in different containers.^a

<p>±8,287.8 (650–26,900) FL.^a Fresh stool produced 10,058</p><p>^b Means and standard deviation (range) derived from 30 different stool samples.</p><p>^c Nonparametric Kruskal-Wallis test was analyzed.</p