Thermophilic potentially pathogenic amoebae isolated from natural water bodies in Poland and their molecular characterization

The free-living amoebae (FLA) may live in the environment and also within other organisms as parasites and then they are calledamphizoic. They are potentially pathogenic for humans and animals and are found in water that is a source of infection. Theaim of this study was molecular detection and identification of these FLA in natural water bodies in North-Western Poland to evaluate the risk of the pathogenic amoebae infections. We examined surface water samples collected from 50 sites and first,the tolerance thermic test was performed in order to select thermophilic, potentially pathogenic strains. For molecular identi-fication of FLA, regions of 18S rDNA, 16S rDNA and intergenic spacers were amplified. AcanthamoebaT4 and T16 genotypesof 18S rDNA gene and 18S rDNA of H. vermiformiswere detected. We identified two variants of AcanthamoebaT4 genotype,two variants of AcanthamoebaT16 genotype and one variant of H. vermiformis. Identification of the T16 genotype and H. ver-miformisin water was for the first time in Poland. Additionally, we made attempts to adapt the RLB method for detection anddifferentiation of FLA species and strains. PCR seems to be more sensitive than RLB hybridization, though.