The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Maureen B Taylor - One of the best experts on this subject based on the ideXlab platform.
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the detection of Enteric Viruses in selected urban and rural river water and sewage in kenya with special reference to rotaViruses
Journal of Applied Microbiology, 2010Co-Authors: Nicholas M Kiulia, Rembuluwani Netshikweta, Nicola Page, W B Van Zyl, M M Kiraithe, Atunga Nyachieo, Jason M Mwenda, Maureen B TaylorAbstract:Aim: To determine the occurrence of eight human Enteric Viruses in surface water and sewage samples from different geographical areas in Kenya. Methods and Results: Enteric Viruses were recovered from the water and sewage sources by glass-wool adsorption elution and/or polyethylene glycol/NaCl precipitation and detected by singleplex real-time and conventional PCR and reverse transcriptase-PCR assays. One or more Enteric Viruses were detected in nearly all sewage and river water samples except the urban Mbagathi River. The VP7 (G types) and the VP4 (P types) of the rotaViruses (RV) were characterized by multiplex nested PCR methods. The G and P types could be determined in 95·5% of the RV strains, respectively. Mixed G types were detected with G12 and G1 predominating, and unusual G types, G5 and G10, were present. P[4] predominated in the urban Karen sewage samples, while P[8] predominated in the urban and rural streams. Conclusions: The high prevalence of RVs in surface water highlights the importance of assessing the water sources used for domestic purposes for viral contamination. Significance and Impact of the Study: This study demonstrates the benefit of environmental surveillance as an additional tool to determine the epidemiology of RVs and other Enteric Viruses circulating in a given community.
Eiji Haramoto - One of the best experts on this subject based on the ideXlab platform.
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applicability of crassphage pepper mild mottle virus and tobacco mosaic virus as indicators of reduction of Enteric Viruses during wastewater treatment
Scientific Reports, 2020Co-Authors: Sarmila Tandukar, Samendra P. Sherchan, Eiji HaramotoAbstract:This study was conducted to evaluate the applicability of crAssphage, pepper mild mottle virus (PMMoV), and tobacco mosaic virus (TMV) as indicators of the reduction of human Enteric Viruses during wastewater treatment. Thirty-nine samples were collected from three steps at a wastewater treatment plant (raw sewage, secondary-treated sewage, and final effluent) monthly for a 13-month period. In addition to the three indicator Viruses, eight human Enteric Viruses [human adenoViruses, JC and BK polyomaViruses, Aichi virus 1 (AiV-1), enteroViruses, and noroViruses of genogroups I, II, and IV] were tested by quantitative PCR. Indicator Viruses were consistently detected in the tested samples, except for a few final effluents for crAssphage and TMV. The mean concentrations of crAssphage were significantly higher than those of most tested Viruses. The concentrations of crAssphage in raw sewage were positively correlated with the concentrations of all tested human Enteric Viruses (p <0.05), suggesting the applicability of crAssphage as a suitable indicator to estimate the concentrations of human Enteric Viruses in raw sewage. The reduction ratios of AiV-1 (1.8 ± 0.7 log10) were the lowest among the tested Viruses, followed by TMV (2.0 ± 0.3 log10) and PMMoV (2.0 ± 0.4 log10). Our findings suggested that the use of not only AiV-1 and PMMoV but also TMV as indicators of reductions in viral levels can be applicable during wastewater treatment.
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Co-Infection by Waterborne Enteric Viruses in Children with Gastroenteritis in Nepal
Healthcare (Basel Switzerland), 2019Co-Authors: Sarmila Tandukar, Jeevan B. Sherchand, Dinesh Bhandari, Bikash Malla, Rajani Ghaju Shrestha, Surendra Karki, Ocean Thakali, Eiji HaramotoAbstract:Enteric Viruses are highly contagious and a major cause of waterborne gastroenteritis in children younger than five years of age in developing world. This study examined the prevalence of Enteric virus infection in children with gastroenteritis to identify risk factors for co-infections. In total, 107 stool samples were collected from patients with acute gastroenteritis along with samples of their household drinking water and other possible contamination sources, such as food and hand. The presence of major gastroenteritis-causing Enteric virus species (group A rotaViruses, enteroViruses, adenoViruses, and noroViruses of genogroup I) in stool and water samples was examined using quantitative polymerase chain reaction. Among the 107 stool samples tested, 103 (96%) samples contained at least one of the four tested Enteric Viruses, and the combination of group A rotaViruses and enteroViruses was the most common co-infection (52%, n = 54/103). At least one viral agent was detected in 16 (16%) of 103 drinking water samples. Identical Enteric Viruses were detected in both the stool and water samples taken from the same patients in 13% of cases (n = 13/103). Group A rotaViruses were most frequently found in children suffering from acute diarrhea. No socio-demographic and clinical factors were associated with the risk of co-infection compared with mono-infection. These less commonly diagnosed viral etiological agents in hospitals are highly prevalent in patients with acute gastroenteritis.
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a review on recent progress in the detection methods and prevalence of human Enteric Viruses in water
Water Research, 2018Co-Authors: Eiji Haramoto, Masaaki Kitajima, Akihiko Hata, Jason Robert Torrey, Yoshifumi Masago, Daisuke Sano, Hiroyuki KatayamaAbstract:Waterborne human Enteric Viruses, such as noroViruses and adenoViruses, are excreted in the feces of infected individuals and transmitted via the fecal-oral route including contaminated food and water. Since Viruses are normally present at low concentrations in aquatic environments, they should be concentrated into smaller volumes prior to downstream molecular biological applications, such as quantitative polymerase chain reaction (qPCR). This review describes recent progress made in the development of concentration and detection methods of human Enteric Viruses in water, and discusses their applications for providing a better understanding of the prevalence of the Viruses in various types of water worldwide. Maximum concentrations of human Enteric Viruses in water that have been reported in previous studies are summarized to assess viral abundances in aquatic environments. Some descriptions are also available on recent applications of sequencing analyses used to determine the genetic diversity of viral genomes in water samples, including those of novel Viruses. Furthermore, the importance and significance of utilizing appropriate process controls during viral analyses are discussed, and three types of process controls are considered: whole process controls, molecular process controls, and (reverse transcription (RT)-)qPCR controls. Although no standards have been established for acceptable values of virus recovery and/or extraction-(RT-)qPCR efficiency, use of at least one of these appropriate control types is highly recommended for more accurate interpretation of observed data.
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Presence of Human Enteric Viruses, Protozoa, and Indicators of Pathogens in the Bagmati River, Nepal
Pathogens (Basel Switzerland), 2018Co-Authors: Sarmila Tandukar, Jeevan B. Sherchand, Dinesh Bhandari, Samendra P. Sherchan, Bikash Malla, Rajani Ghaju Shrestha, Eiji HaramotoAbstract:Quantification of waterborne pathogens in water sources is essential for alerting the community about health hazards. This study determined the presence of human Enteric Viruses and protozoa in the Bagmati River, Nepal, and detected fecal indicator bacteria (total coliforms, Escherichia coli, and Enterococcus spp.), human-fecal markers (human Bacteroidales and JC and BK polyomaViruses), and index Viruses (tobacco mosaic virus and pepper mild mottle virus). During a one-year period between October 2015 and September 2016, a total of 18 surface water samples were collected periodically from three sites along the river. Using quantitative polymerase chain reaction, all eight types of human Enteric Viruses tested—including adenoViruses, noroViruses, and enteroViruses, were detected frequently at the midstream and downstream sites, with concentrations of 4.4–8.3 log copies/L. EnteroViruses and saliViruses were the most frequently detected Enteric Viruses, which were present in 72% (13/18) of the tested samples. Giardia spp. were detected by fluorescence microscopy in 78% (14/18) of the samples, with a lower detection ratio at the upstream site. Cryptosporidium spp. were detected only at the midstream and downstream sites, with a positive ratio of 39% (7/18). The high concentrations of Enteric Viruses suggest that the midstream and downstream regions are heavily contaminated with human feces and that there are alarming possibilities of waterborne diseases. The concentrations of Enteric Viruses were significantly higher in the dry season than the wet season (p < 0.05). There was a significant positive correlation between the concentrations of human Enteric Viruses and the tested indicators for the presence of pathogens (IPP) (p < 0.05), suggesting that these IPP can be used to estimate the presence of Enteric Viruses in the Bagmati River water.
Atheesha Ganesh - One of the best experts on this subject based on the ideXlab platform.
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Water quality indicators: Bacteria, coliphages, Enteric Viruses
International Journal of Environmental Health Research, 2013Co-Authors: Johnson Lin, Atheesha GaneshAbstract:Water quality through the presence of pathogenic Enteric microorganisms may affect human health. Coliform bacteria, Escherichia coli and coliphages are normally used as indicators of water quality. However, the presence of above-mentioned indicators do not always suggest the presence of human Enteric Viruses. It is important to study human Enteric Viruses in water. Human Enteric Viruses can tolerate fluctuating environmental conditions and survive in the environment for long periods of time becoming causal agents of diarrhoeal diseases. Therefore, the potential of human pathogenic Viruses as significant indicators of water quality is emerging. Human AdenoViruses and other Viruses have been proposed as suitable indices for the effective identification of such organisms of human origin contaminating water systems. This article reports on the recent developments in the management of water quality specifically focusing on human Enteric Viruses as indicators.
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REVIEW ARTICLE Water quality indicators: bacteria, coliphages, Enteric Viruses
2013Co-Authors: Johnson Lin, Atheesha GaneshAbstract:Water quality through the presence of pathogenic Enteric microorganisms may affect human health. Coliform bacteria, Escherichia coli and coliphages are normally used as indicators of water quality. However, the presence of above-mentioned indicators do not always suggest the presence of human Enteric Viruses. It is important to study human Enteric Viruses in water. Human Enteric Viruses can tolerate fluctuating environmental conditions and survive in the environment for long periods of time becoming causal agents of diarrhoeal diseases. Therefore, the potential of human pathogenic Viruses as significant indicators of water quality is emerging. Human AdenoViruses and other Viruses have been proposed as suitable indices for the effective identification of such organisms of human origin contaminating water systems. This article reports on the recent developments in the management of water quality specifically focusing on human Enteric Viruses as indicators.
Kristen E. Gibson - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Methods for Evaluating the Thermal Stability of Human Enteric Viruses
Food and Environmental Virology, 2015Co-Authors: Sabastine E. Arthur, Kristen E. GibsonAbstract:Human Enteric Viruses have been identified as one of the predominant causative agents of food-borne illnesses in developed countries, and it is estimated that human norovirus accounts for a majority of these illnesses each year. Not all of these Viruses can be cultured and hence relatively little is known about their pathogenesis and physicochemical properties. To overcome this, researchers have utilized different virus surrogates for the study of non-cultivable human Enteric Viruses. In this review, we discuss various methods utilized for the evaluation of the thermal stability of human Enteric Viruses, compare the results of these methods, and examine how researchers may move toward a single standard approach (i.e., temperatures, virus concentrations, volume/weight of matrices, etc.) for determining thermal inactivation profiles of human Enteric Viruses and their surrogates. Based on our review, we found that temperature, time of exposure, type of matrix, analysis type, type of heat application, and the concentration and volume of virus used in the experiments were highly variable across virus surrogates even for the same surrogates. Because of these differences—along with the inherent limitations of using surrogate Viruses—comparison of these methods and how the results may be extrapolated to human Enteric Viruses is quite challenging. As a result, we discuss how researchers may move toward a single standard approach for determining thermal inactivation profiles of human Enteric Viruses and their surrogates.
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evaluation of human Enteric Viruses in surface water and drinking water resources in southern ghana
American Journal of Tropical Medicine and Hygiene, 2011Co-Authors: Kristen E. Gibson, Melissa C Opryszko, James T Schissler, Yayi Guo, Kellogg J SchwabAbstract:An estimated 884 million people worldwide do not have access to an improved drinking water source, and the microbial quality of these sources is often unknown. In this study, a combined tangential flow, hollow fiber ultrafiltration (UF), and real-time PCR method was applied to large volume (100 L) groundwater (N = 4), surface water (N = 9), and finished (i.e., receiving treatment) drinking water (N = 6) samples for the evaluation of human Enteric Viruses and bacterial indicators. Human Enteric Viruses including norovirus GI and GII, adenovirus, and polyomavirus were detected in five different samples including one groundwater, three surface water, and one drinking water sample. Total coliforms and Escherichia coli assessed for each sample before and after UF revealed a lack of correlation between bacterial indicators and the presence of human Enteric Viruses.
Lars Jurzik - One of the best experts on this subject based on the ideXlab platform.
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Distribution of Escherichia coli, coliphages and Enteric Viruses in water, epilithic biofilms and sediments of an urban river in Germany
The Science of the total environment, 2018Co-Authors: Martin Mackowiak, Mats Leifels, Ibrahim Ahmed Hamza, Lars Jurzik, Jost WingenderAbstract:Fecal contamination of surface water is commonly evaluated by quantification of bacterial or viral indicators such as Escherichia coli and coliphages, or by direct testing for pathogens such as Enteric Viruses. Retention of fecally derived organisms in biofilms and sediments is less frequently considered. In this study, we assessed the distribution of E. coli, somatic coliphages, and Enteric Viruses including human adenovirus (HAdV), enterovirus (EV), norovirus genogroup GII (NoV GII) and group A rotavirus (RoV) in an urban river environment in Germany. 24 samples each of water, epilithic biofilms and sediments were examined. E. coli and somatic coliphages were prevalent not only in the flowing water, but also in epilithic biofilms and sediments, where they were accumulated compared to the overlying water. During enhanced rainfall, E. coli and coliphage concentrations increased by approximately 2.5 and 1 log unit, respectively, in the flowing water, whereas concentrations did not change significantly in epilithic biofilms and sediments. The occurrence of human Enteric Viruses detected by qPCR was higher in water than in biofilms and sediments. 87.5% of all water samples were positive for HAdV. Enteric Viruses found less frequently were EV, RoV and NoV GII in 20.8%, 16.7% and 8.3% of the water samples, respectively. In epilithic biofilms and sediments, HAdV was found in 54.2% and 50.0% of the samples, respectively, and EV was found in 4.2% of both biofilm and sediment samples. RoV and NoV GII were not detected in any of the biofilms and sediments. Overall, the prevalence of Enteric Viruses was in the order of HAdV > EV > RoV ≥ NoV GII. In conclusion, epilithic biofilms and sediments can be reservoirs for fecal indicators and Enteric Viruses and thus should be taken into consideration when assessing microbial pollution of surface water environments.
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chemical and microbiological parameters as possible indicators for human Enteric Viruses in surface water
International Journal of Hygiene and Environmental Health, 2010Co-Authors: Lars Jurzik, Ibrahim Ahmed Hamza, Wilfried Puchert, Klaus Uberla, Michael WilhelmAbstract:There are still conflicting results on the suitability of chemical and microbiological parameters as indicators for the viral contamination of surface waters. In this study, conducted over 20 months, the abundance of human adenovirus, human polyomavirus, enterovirus, group A rotavirus and norovirus was determined in Ruhr and Rhine rivers, Germany. Additionally, prevalence of different possible indicators such as somatic coliphages, E. coli, intestinal enterococci, and total coliforms was also considered. Moreover, the chemical parameter TCPP (tris-(2-chloro-, 1-methyl-ethyl)-phosphate), characterized by environmental stability and human origin, was included. Furthermore, chemical parameters (fluoride, chloride, nitrate, nitrite, bromide, phosphate, and sulfate) which may influence the stability and subsequently the detection rates of Viruses in aquatic environment were measured. Quantitative Real-Time (RT-)PCR and double agar layer test were used for the quantification of human Enteric Viruses and somatic coliphages, respectively. The analyses for E. coli, total coliforms, and intestinal enterococci were done with respect to the standard reference method. The chemical parameters were measured by liquid chromatography of ions and by gas chromatography-flame photometer detector (GC-FPD), respectively. We demonstrated that human adenovirus had the highest detection rate (96.3%), followed by somatic coliphages (73.5%), human polyomavirus (68.6%), and rotavirus (63.5%). However, norovirus GII and enterovirus were found in only 25.7 and 17.8%, respectively. The concentration of the viral genome ranged between 16 and 1.1 × 106 gen. equ./l (genome equivalents/l) whereas the concentrations for TCPP ranged between 0.01 and 0.9g/l. The results of the Pearson correlation showed no association between TCPP and any other microbiological parameter. None of the other tested chemical parameters correlated negatively, and therefore they do not influence the stability of Enteric Viruses. We conclude that neither TCPP nor any other chemical or microbiological parameter can be used as a reliable indicator for the presence of Enteric Viruses in river water. © 2010 Published by Elsevier GmbH.