Free-living protozoa in drinking water supplies: community composition and role as hosts for Legionella pneumophila

“Free-living protozoa, which feed on bacteria, play an important role in the communities of microorganisms and invertebrates in drinking water supplies and in (warm) tap water installations. Several bacteria, including opportunistic human pathogens such as Legionella pneumophila, are able to survive and replicate within protozoan hosts, and certain free-living protozoa are opportunistic human pathogens as well. However, not much is known about the occurrence of these organisms in drinking water supplies in relation to water quality and other environmental conditions. This lack of knowledge may in part be attributed to the limitations of microscopic techniques and cultivation methods for detection and identification of protozoa. In the investigations described in this thesis, molecular
methods were applied to identify communities of free-living protozoa in drinking water supplies and to elucidate the effects of environmental conditions on the growth of these organisms. Molecular methods were also used to detect and identify protozoan hosts, both known and yet-undescribed, for L. pneumophila. The eukaryotic communities were studied using terminal restriction fragment length polymorphism (T-RFLP), clone library analyses of partial 18S rRNA gene fragments, and qPCR assays for Acanthamoeba spp. and Hartmannella vermiformis.”

(Citaat: Valster, R.M. – Free-living protozoa in drinking water supplies: community composition and role as hosts for Legionella pneumophila)