Isolation and molecular characterization of free-living amoebae from different water sources in Italy

Int J Environ Res Public Health. 2015 Mar 24;12(4):3417-27. doi: 10.3390/ijerph120403417.


Free-living amoebae (FLA) are protozoa ubiquitous in Nature, isolated from a variety of environments worldwide. In addition to their natural distribution, some species have been found to be pathogenic to humans. In the present study a survey was conducted in order to evaluate the presence and to characterize at molecular level the isolates of amoebic organisms collected from different water sources in Italy. A total of 160 water samples were analyzed by culture and microscopic examination. FLA were found in 46 (28.7%) of the investigated water samples. Groundwater, well waters, and ornamental fountain waters were the sources with higher prevalence rates (85.7%, 50.0%, and 45.9%, respectively). Identification of FLA species/genotypes, based on the 18S rDNA regions, allowed to identify 18 (39.1%) Acanthamoeba isolates (genotypes T4 and T15) and 21 (45.6%) Vermamoeba vermiformis isolates. Other FLA species, including Vahlkampfia sp. and Naegleria spp., previously reported in Italy, were not recovered. The occurrence of potentially pathogenic free-living amoebae in habitats related to human population, as reported in the present study, supports the relevance of FLA as a potential health threat to humans.

MeSH terms

  • Amoebozoa / classification*
  • Amoebozoa / genetics
  • Amoebozoa / isolation & purification*
  • DNA, Protozoan / analysis
  • DNA, Ribosomal / analysis
  • Genotype
  • Italy
  • Water Microbiology*


  • DNA, Protozoan
  • DNA, Ribosomal