ISOLATION AND IDENTIFICATION OF ACANTHAMOEBA SPP FROM WATER AND SOIL IN SOUTHERN THAILAND

Abstract

Acanthamoeba spp are free-living amoebae commonly found in a wide range of environment settings and can cause granulomatous amoebic encephalitis and Acanthamoeba keratitis. Here, we collected water (n = 51) and soil (n = 20) samples from areas associated with human activities in southern Thailand. Free-living amoebae were found in 56 samples, 56% morphologically identified as Acanthamoeba spp, among which, based on cyst morphology, 15, 50 and 35% were placed in morphological group I, II and III, respectively. Based on 18S rDNA gene sequences, 19 isolates were confirmed as Acanthamoeba spp, among which 6, 3, 1, 1, 2 and 2 isolates belonged to genotype T4, T5, T11, T17, T18, and T20, respectively. Acanthamoeba spp in morphological groups II and III and genotypes T4, T5, T11, and T18 are believed to be associated with serious human infection. This is the first report of the environmental presence of clinically pathogenic Acanthamoeba spp in southern Thailand.