MUNSON, D.A.*; PAGET, T.A.; Washington College, Chestertown, MD; The University of Hull, Hull, UK: Isolation of Acanthamoeba from North Sea Coastal Environments

Acanthamoeba spp. are free-living amoebae that are ubiquitous in nature. Some species in the genus are opportunistic pathogens of humans. Acanthamoeba spp. have been isolated from a wide variety of sources including marine and fresh water. These environments are often used for recreational purposes and may represent a potential source of infection. In this study we assess the impact of “pollutants” on the isolation rates and species/pathogen distribution of Acanthamoeba in six North Sea Coastal sites. Environmental data for each site was obtained from the Environment Agency and the Scottish Environmental Protection Agency. Amoebae were isolated from these sediments using bacterial overlay plates. From initial isolates, Acanthamoeba were subcultured and identified/speciated using cyst morphology and Hae III restriction of a ribosomal DNA PCR product. The pathogenicity of isolates was assayed by culture on high osmolarity plates and by growth at 37C. Acanthamoeba were isolated from 34 of 41 sediment samples. The majority of isolates (65/77) were from Groups II & II based on morphology and 42 were speciated using restriction analysis. From the data collected it appears that environment has a significant effect on species diversity, with diversity being reduced in polluted environments. Interestingly the majority of pathogens were isolated from “clean” waters.