Search

Aims: In this study, we report a new, simple methodology for the monitoring of Cryptosporidium oocysts and Giardia cysts in drinking water samples, ranging from 10- to 1000-l, which combines a new ARAD microfibre filtration of the (oo)cysts from drinking water and loop-mediated isothermal amplification (LAMP) of a human pathogenic Cryptosporidium parvum, Cryptosporidium hominis, Cryptosporidium meleagridis and Giardia duodenalis Assemblage A and B specific DNA sequence., Methods and Results: During the evaluation of the new concentration and detection technique, spiked reagent and matrix water samples plus blank samples were filtered and tested. In total, 27 samples have been investigated. The results clearly demonstrate that the methodology of using a new ARAD filter, which passed through 1000 l of drinking water with high turbidity (2 NTU), and followed by the LAMP assay was able to detect at least one (oo)cyst in 10 l of drinking water based on a 1000-l sample, taken over a 24-h period., Conclusions: The described protozoa detection methodology is sensitive, rapid and cost-effective., Significance and Impact of the Study: This effective procedure will be useful for small waterworks to achieve continuous monitoring and is also of value for screening catchments to identify those that require further treatment and more detailed microscopic counts.

Safe drinking water is a top priority in preventing disease outbreaks and is of general concern to everyone. This study examines the occurrence of Cryptosporidium and Giardia in Hungarian drinking water supplies for the first time. A total of 76 raw and drinking water samples were examined using the U.S. EPA Method 1623. From these 15 of 34 (48.4%) raw water samples tested positive for Giardia and 7 (26.6%) for Cryptosporidium. Twelve of 45 (26.7%) drinking water samples were positive for Giardia and 6 (13.3%) for Cryptosporidium. Overall, Giardia cysts and/or Cryptosporidium oocysts were detected in 48% of the raw water samples and 35% of the drinking water samples. The highest levels in drinking water were found to be 3 oocysts/100 litres of Cryptosporidium and 63.6 cysts/100 litres for Giardia, enough to cause giardiasis. The highest levels in raw water were 1,030 cysts/100 litres for Giardia and 50 oocysts/100 litres for Cryptosporidium and higher oocyst densities were associated with source water receiving effluents from sewage treatment plants or originating from a forest environment. In addition to this monitoring, riverbank filtrated water and raw water from the River Danube in Budapest were monitored in order to ascertain protozoan removal efficiency of riverbank filtration (RBF). A total of 157 samples, including 87 samples from the River Danube and 70 samples post RBF, were examined. Cryptosporidium and Giardia were detected regularly in the river water but never in riverbank filtered water suggesting the effectiveness of RBF as a purification method. The occurrence of Cryptosporidium oocysts and Giardia cysts in the investigated water supplies may require the water utilities and water authorities in Hungary to apply additional monitoring and treatment and/or watershed controls.

Abstract: We investigated the prevalence of Giardia and Cryptosporidium species and analysed the genotypes in 36 samples collected from different water sources and various geographic areas in Hungary. Samples were collected from drinking water and sewage treatment plants and from the recreation area of Lake Balaton. The (oo)cysts were purified according to the US EPA 1623 method and they were detected by immunofluorescence test (IFT). Genomic DNA was extracted from all samples and then the GDH target gene for Giardia and the SSUrDNA for both Giardia and for Cryptosporidium species were amplified by PCR. 24 out of 36 samples (67%) were Giardia positive and 15 (42%) were Cryptosporidium positive by IFT. PCR confirmed that 13 out of 36 samples (36%) were Giardia positive and 10 (28%) contained Cryptosporidium. Twelve Giardia and two Cryptosporidium PCR products were successfully sequenced. In seven samples G. lamblia Assemblage A and in one sample Assemblage B and in four cases Assemblages A and B have been found. In one sample C. parvum and in the other separate sample C. meleagridis were detected. Sequence analysis revealed a new subtype of G. duodenalis complex, clustered close to the Assemblage A group. This study provides the first report on simultaneous detection and genotyping of G. duodenalis and Cryptosporidium species from water supplies in Hungary. [Copyright &y& Elsevier]