Municipal wastewater treatment plants play a vital role in reducing the microbial load of sewage before the end-products are discharged to surface waters (final effluent) or local environments (biosolids). This study was to investigate the presence of human-virulent microsporidian spores (Enterocytozoon bieneusi, Encephalitozoon intestinalis, and Encephalitozoon hellem) and enterococci during treatment processes at four Irish municipal secondary wastewater treatment plants (plants A–D). Microsporidian abundance was significantly related to seasonal increase in water temperature. Plant A had the least efficient removal of E. intestinalis spores (32%) in wastewater, with almost 100% removal at other plants both in April and July. Some negative removal efficiencies were obtained for E. bieneusi (at plants C and D, −100%) and for E. hellem (at plants A and D, −90% and −50%). In addition, a positive correlation was found between the levels of enterococci and E. bieneusi in July (r = 0.72, P < 0.05). In terms of the dewatered biosolids, a median concentration as high as 32,000 spores/Kg of E. hellem was observed at plant D in July. Plant C sewage sludge contained the lowest microsporidian loadings (E. bieneusi; 450 spores/L and 1,000 spores/L in April and July, respectively). This study highlights the seasonal variation in concentrations of microsporidian spores in the incoming sewage. Spores in final effluents and dewatered biosolids can be the source of human-virulent microsporidian contamination to the local environment. This emphasizes a considerably high public health risk when sewage-derived biosolids are spread during summer months. This study also suggested enterococci as a potential indicator of the presence of microsporidian spores in wastewater, especially for E. bieneusi.
Parasitology Research (2011) 109(3), 595-603

Ostroumov S. A. The theory of the hydrobiological mechanism of water self-purification in water bodies: from theory to practice [Proceedings of the 4th International Iran and Russia Conference in Agricluture and Natural Resources. Shahrekord-Iran. Sept. 8-10, 2004]. p.(p.1251 -1253. Bibliogr. 11 refs). Sergei A. Ostroumov Faculty of Biology, Lomonosov Moscow State University, Moscow 119234; Russia; Email: saostro@online.ru Abstract.New data on effects of chemicals (surfactants) on water filtration by aquatic invertebrates are reported. The basics of the new theory of the polyfunctional role of biota in self-purification of water in aquatic ecosystems (lakes, rivers, man-made reservoirs) are formulated. The theory covers the following: sources of energy for the mechanisms of self-purification; the main functional blocks of the mechanism of water self-purification; the system of the main processes that are involved; analysis of the degree of participation of the main groups of aquatic organisms; degree of reliability and the main mechanisms providing the reliability of water self-purification; biotic regulation of the processes; the attitude of the mechanism of self-purification towards the external influences/impacts; applications and conclusions relevant to the practice of sustainable use of water resources, including some new approaches in preventing eutrophication and chemical pollution. --Key Words: pollution, water quality, theory of water self-purification, lakes, rivers, role of organisms, biota, functioning, aquatic ecosystems, ecotoxicology, sustainable use of aquatic resources, environmental safety, toxicants, pollutants, xenobiotics, freshwater and marine ecosystems, sodium dodecyl sulphate,SDS; tetradecyltrimethylammonium bromide,TDTMA; Triton X-100, synthetic surfactants, tensides, new bioassays, anthropogenic effects,man-made effects,wastewater treatment http://iirc.narod.ru/4conference/Fullpaper/40037.pdf
Ostroumov S. A. The theory of the hydrobiological mechanism of water self-purification in water bodies: from theory to practice [Proceedings of the 4th International Iran and Russia Conference in Agricluture and Natural Resources. Shahrekord-Iran. Sept. 8-10, 2004].