Molecular characterization of Acanthamoeba isolated in water treatment plants and comparison with clinical isolates

Parasitology Laboratory, San Pablo CEU University, Urbanización Montepríncipe, Boadilla del Monte, Madrid, Spain.
Parasitology Research (Impact Factor: 2.1). 03/2012; 111(1):383-92. DOI: 10.1007/s00436-012-2849-2
Source: PubMed


A total of 116 samples (44 clinical specimens and 72 environmental samples) have been analyzed for the presence of Acanthamoeba. The environmental samples (ESs) were collected from four drinking water treatment plants (DWTP, n=32), seven wastewater treatment plants (n=28), and six locations of influence (n=12) on four river basins from the central area of Spain (winter-spring 2008). Water samples were concentrated by using the IDEXX Filta-Max(®) system. Acanthamoeba was identified in 65 of the 72 ESs by culture isolation (90.3%) and 63 by real-time PCR (87.5%), resulting in all sampling points (100%) positive for Acanthamoeba when considering both techniques and all the time period analyzed. Nine of the 44 clinical specimens were positive for Acanthamoeba. Seventeen Acanthamoeba strains (eight from four DWTP and nine from clinical samples) were also established in axenic-PYG medium. Twenty-four of the ESs and the 17 Acanthamoeba sp. strains were genotyped as T4/1, T4/8, and T4/9. The eight strains isolated from the DWTP samples were inoculated in nude mouse to ascertain their potential pathogenicity in this model. Animals that were inoculated died or showed central nervous system symptoms 9 days post-inoculation. Examination of immunofluorescence-stained brain and lung tissue sections showed multiple organisms invading both tissues, and re-isolation of throphozoites was successful in these tissues of all infected animals. For the first time, potentially pathogenic Acanthamoeba T4 has been detected in 100% of different types of water samples including tap water and sewage effluents in the central area of Spain suggesting a potential health threat for humans especially for the contact lens wearers.

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Available from: Govinda Visvesvara, Apr 17, 2015
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    • "out tertiary treatment (García et al., 2011; Magnet et al., 2012; Mosteo et al., 2013). In addition, this research showed that thermophilic digestion processes and dehydration are also ineffective against Acanthamoeba cysts. "
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    ABSTRACT: Biological urban water treatment plants utilize microorganisms for wastewater purification so that microbiological characterization of processes is very important. In addition, its removal in the effluent and outlet sludge for their reuse is important. This work aims to characterize the presence of bacteria and parasites along the processes in wastewater treatment plant (WWTP) and the possibility of using the purifying water and sludge in agriculture. The results show a high level of Escherichia coli in the raw water. Although their total removal is not achieved, a reduction of 2.34 and 1.36 log in the concentration of E. coli was produced along the water and sludge treatment lines, respectively, being the trickling filters (TF) and autothermal thermophilic aerobic digestion (ATAD) the most effective processes against bacteria. Clostridium perfringens, which is a Grampositive bacillus and fecal contamination indicator, although less usual than E.coli, is detected in washing water of solids which are stored in anoxic conditions and in the sludge treatment line where dissolved oxygen is absent including in the outlet of plant. Salmonella spp, Entamoeba and Cryptosporidium were not detected in any of the samples, meanwhile Giardia duodenalis was identified only in two samples from washing coarse solids and sludge, but it was not identified in outlet water and sludge. Acanthamoeba was the most frequent protozoa isolated.
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    • "Acanthamoeba spp. have been isolated and identified in many countries around the world, for example in Bulgaria (Tsetkova et al. 2004), Iran (Mahmoudi et al. 2012), Spain (Magnet et al. 2012), Brazil (Duarte et al. 2013), Japan (Edagawa et al. 2009), the USA (John and Howard 1995), Switzerland (Gianinazzi et al. 2009), and also in Poland (Kasprzak and Mazur 1972). "
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