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Institute of Environmental Science and Research Ltd
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Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 28-05-2016
DOI: 10.1007/S00436-016-5112-4
Abstract: Differentiation between viable and non-viable hookworm ova in environmental s les is necessary in order to implement strategies to mitigate re-infections in endemic regions. In this study, an untargeted metabolic profiling method was developed that utilised gas chromatography-mass spectrometry (GC-MS) in order to investigate hookworm ova viability. Ancylostoma caninum was used to investigate the metabolites within viable and non-viable ova. Univariate and multivariate statistical analyses of the data resulted in the identification of 53 significant metabolites across all hookworm ova s les. The major compounds observed in viable and non-viable hookworm ova were tetradecanoic acid, commonly known as myristic acid [fold change (FC) = 0.4], and dodecanoic acid, commonly known as lauric acid (FC = 0.388). Additionally, the viable ova had self-protecting metabolites such as prostaglandins, a typical feature absent in non-viable ova. The results of this study demonstrate that metabolic profiling using GC-MS methods can be used to determine the viability of canine hookworm ova. Further studies are needed to assess the applicability of metabolic profiling using GC-MS to detect viable hookworm ova in the mixed (viable and non-viable) populations from environmental s les and identify the metabolites specific to human hookworm species.
Publisher: Elsevier BV
Date: 04-2014
DOI: 10.1016/J.WATRES.2013.12.021
Abstract: In this study, quantitative PCR (qPCR) was used for the detection of four opportunistic bacterial pathogens in water s les collected from 72 rainwater tanks in Southeast Queensland, Australia. Tank water s les were also tested for fecal indicator bacteria (Escherichia coli and Enterococcus spp.) using culture-based methods. Among the 72 tank water s les tested, 74% and 94% s les contained E. coli and Enterococcus spp., respectively, and the numbers of E. coli and Enterococcus spp. in tank water s les ranged from 0.3 to 3.7 log₁₀ colony forming units (CFU) per 100 mL of water. In all, 29%, 15%, 13%, and 6% of tank water s les contained Aeromonas hydrophila, Staphylococcus aureus, Pseudomonas aeruginosa and Legionella pneumophila, respectively. The genomic units (GU) of opportunistic pathogens in tank water s les ranged from 1.5 to 4.6 log₁₀ GU per 100 mL of water. A significant correlation was found between E. coli and Enterococcus spp. numbers in pooled tank water s les data (Spearman's rs = 0.50 P < 0.001). In contrast, fecal indicator bacteria numbers did not correlate with the presence/absence of opportunistic pathogens tested in this study. Based on the results of this study, it would be prudent, to undertake a Quantitative Microbial Risk Assessment (QMRA) analysis of opportunistic pathogens to determine associated health risks for potable and nonpotable uses of tank water.
Publisher: Oxford University Press (OUP)
Date: 05-06-2014
DOI: 10.1111/LAM.12285
Abstract: In this study, the relative inactivation of faecal indicator bacteria (FIB) namely Escherichia coli, enterococci and sewage markers [Bacteroides HF183 and human adenoviruses (HAVs)] was assessed in sewage-spiked freshwater and seawater microcosms under ambient subtropical climatic conditions. The numbers of declining FIB were measured with culture-based methods, whereas the numbers of sewage markers were measured with qPCR assays. The T90 inactivation times of E. coli, enterococci and the HF183 markers in both freshwater and seawater microcosms were <3·5 days, suggesting the suitability of the HF183 marker to identify recent sewage pollution events. The T90 value of HAVs (9·4-13 days), however, was significantly higher than FIB and the HF183 marker in both freshwater (P < 0·001) and seawater (P < 0·05) microcosms. Therefore, we recommend that HAVs should be used as an additional marker to adequately assess the potential health risks associated with longer-term sewage-polluted environmental waters. In this study, we have shown that the persistence of the Bacteroides HF183 marker in freshwater and seawater microcosms was similar to faecal indicator bacteria (Escherichia coli and enterococci), whereas human adenoviruses (HAVs) persisted relatively longer. These findings suggest the suitability of both the markers to identify sewage pollution in environmental waters. However, HF183 marker appeared to be more useful than HAVs in identifying recent sewage pollution. As, HAVs may remain infective for lengthy periods, it should be used in conjunction with the HF183 marker to obtain information on the potential human health risks associated with sewage-polluted freshwater and seawater.
Publisher: Elsevier BV
Date: 06-2016
Publisher: Oxford University Press (OUP)
Date: 07-2020
DOI: 10.1093/JTM/TAAA116
Abstract: Wastewater-based epidemiology (WBE) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be an important source of information for coronavirus disease 2019 (COVID-19) management during and after the pandemic. Currently, governments and transportation industries around the world are developing strategies to minimize SARS-CoV-2 transmission associated with resuming activity. This study investigated the possible use of SARS-CoV-2 RNA wastewater surveillance from airline and cruise ship sanitation systems and its potential use as a COVID-19 public health management tool. Aircraft and cruise ship wastewater s les (n = 21) were tested for SARS-CoV-2 using two virus concentration methods, adsorption–extraction by electronegative membrane (n = 13) and ultrafiltration by Amicon (n = 8), and five assays using reverse-transcription quantitative polymerase chain reaction (RT-qPCR) and RT-droplet digital PCR (RT-ddPCR). Representative qPCR licons from positive s les were sequenced to confirm assay specificity. SARS-CoV-2 RNA was detected in s les from both aircraft and cruise ship wastewater however concentrations were near the assay limit of detection. The analysis of multiple replicate s les and use of multiple RT-qPCR and/or RT-ddPCR assays increased detection sensitivity and minimized false-negative results. Representative qPCR licons were confirmed for the correct PCR product by sequencing. However, differences in sensitivity were observed among molecular assays and concentration methods. The study indicates that surveillance of wastewater from large transport vessels with their own sanitation systems has potential as a complementary data source to prioritize clinical testing and contact tracing among disembarking passengers. Importantly, s ling methods and molecular assays must be further optimized to maximize detection sensitivity. The potential for false negatives by both wastewater testing and clinical swab testing suggests that the two strategies could be employed together to maximize the probability of detecting SARS-CoV-2 infections amongst passengers.
Publisher: American Chemical Society (ACS)
Date: 22-07-2015
Abstract: In this study, we have evaluated the performance characteristics (host-specificity and -sensitivity) of four human wastewater-associated Escherichia coli (E. coli) genetic markers (H8, H12, H14, and H24) in 10 target (human) and nontarget (cat, cattle, deer, dog, emu, goat, horse, kangaroo, and possum) host groups in Southeast Queensland, Australia. The overall host-sensitivity values of the tested markers in human wastewater s les were 1.0 (all human wastewater s les contained the E. coli genetic markers). The overall host-specificity values of these markers to differentiate between human and animal host groups were 0.94, 0.85, 0.72, and 0.57 for H8, H12, H24, and H14, respectively. Based on the higher host-specificity values, H8 and H12 markers were chosen for a validation environmental study. The prevalence of the H8 and H12 markers was determined among human wastewater E. coli isolates collected from a wastewater treatment plant (WWTP). Among the 97 isolates tested, 44 (45%) and 14 (14%) were positive for the H8 and H12 markers, respectively. A total of 307 E. coli isolates were tested from environmental water s les collected in Brisbane, of which 7% and 20% were also positive for the H8 and H12 markers, respectively. Based on our results, we recommend that these markers could be useful when it is important to identify the source(s) of E. coli (whether they originated from human wastewater or not) in environmental waters.
Publisher: American Chemical Society (ACS)
Date: 18-02-2015
DOI: 10.1021/ES505477N
Abstract: Quantitative PCR (qPCR) assays were used to determine the concentrations of E. coli including shiga toxin-producing E. coli (STEC) associated virulence genes (eaeA, stx1, stx2, and hlyA) in ten animal species (fecal sources) and environmental water s les in Southeast Queensland, Australia. The mean Log10 concentrations and standard deviations of E. coli 23S rRNA across fecal sources ranged from 1.3 ± 0.1 (horse) to 6.3 ± 0.4 (cattle wastewater) gene copies at a test concentration of 10 ng of DNA. The differences in mean concentrations of E. coli 23S rRNA gene copies among fecal source s les were significantly different from each other (P < 0.0001). Among the virulence genes, stx2 (25%, 95% CI, 17-33%) was most prevalent among fecal sources, followed by eaeA (19%, 95% CI, 12-27%), stx1 (11%, 95% CI, 5%-17%) and hlyA (8%, 95% CI, 3-13%). The Log10 concentrations of STEC virulence genes in cattle wastewater s les ranged from 3.8 to 5.0 gene copies at a test concentration of 10 ng of DNA. Of the 18 environmental water s les tested, three (17%) were positive for eaeA and two (11%) s les were also positive for the stx2 virulence genes. The data presented in this study will aid in the estimation of quantitative microbial risk assessment (QMRA) from fecal pollution of domestic and wild animals in drinking/recreational water catchments.
Publisher: Elsevier BV
Date: 02-2021
Publisher: American Society for Microbiology
Date: 15-07-2016
DOI: 10.1128/AEM.00892-16
Abstract: Avian and possum fecal droppings may negatively impact roof-harvested rainwater (RHRW) water quality due to the presence of zoonotic pathogens. This study was aimed at evaluating the performance characteristics of a possum feces-associated (PSM) marker by screening 210 fecal and wastewater s les from possums ( n = 20) and a range of nonpossum hosts ( n = 190) in Southeast Queensland, Australia. The host sensitivity and specificity of the PSM marker were 0.90 and 0.95 (maximum value, 1.00), respectively. The mean concentrations of the GFD marker in possum fecal DNA s les (8.8 × 10 7 gene copies per g of feces) were two orders of magnitude higher than those in the nonpossum fecal DNA s les (5.0 × 10 5 gene copies per g of feces). The host sensitivity, specificity, and concentrations of the avian feces-associated GFD marker were reported in our recent study (W. Ahmed, V. J. Harwood, K. Nguyen, S. Young, K. Hamilton, and S. Toze, Water Res 88:613–622, 2016, 0.1016/j.watres.2015.10.050 ). The utility of the GFD and PSM markers was evaluated by testing a large number of tank water s les ( n = 134) from the Brisbane and Currumbin areas. GFD and PSM markers were detected in 39 of 134 (29%) and 11 of 134 (8%) tank water s les, respectively. The GFD marker concentrations in PCR-positive s les ranged from 3.7 × 10 2 to 8.5 × 10 5 gene copies per liter, whereas the concentrations of the PSM marker ranged from 2.0 × 10 3 to 6.8 × 10 3 gene copies per liter of water. The results of this study suggest the presence of fecal contamination in tank water s les from avian and possum hosts. This study has established an association between the degradation of microbial tank water quality and avian and possum feces. Based on the results, we recommend disinfection of tank water, especially for tanks designated for potable use. IMPORTANCE The use of roof-harvested rainwater (RHRW) for domestic purposes is a globally accepted practice. The presence of pathogens in rainwater tanks has been reported by several studies, supporting the necessity for the management of potential health risks. The sources of fecal pollution in rainwater tanks are unknown. However, the application of microbial source tracking (MST) markers has the potential to identify the sources of fecal contamination in a rainwater tank. In this study, we provide evidence of avian and possum fecal contamination in tank water s les using molecular markers. This study established a potential link between the degradation of the microbial quality of tank water and avian and possum feces.
Publisher: Elsevier BV
Date: 05-2019
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.WATRES.2018.10.088
Abstract: There is a growing move towards using the quantitative polymerase chain (qPCR)-based sewage-associated marker genes to assess surface water quality. However, a lack of understanding about the persistence of many sewage-associated markers creates uncertainty for those tasked with investigating microbial water quality. In this study, we investigated the decay of two qPCR FIB [E. coli (EC), and Enterococcus spp. (ENT) 23S rRNA genes] and four sewage-associated microbial source tracking (MST) marker genes [human Bacteroides HF183 16S rRNA, adenovirus (HAdV), and polyomavirus (HPyV), and crAssphage, a recently described bacteriophage in feces], in outdoor mesocosms containing fresh and marine waters and their corresponding sediments. Decay rates of EC 23S rRNA, ENT 23S rRNA, and HF183 16S rRNA were significantly (p < 0.05) faster than the HAdV, HPyV and crAssphage markers in water s les from all mesocosms. In general, decay rates of bacterial targets were similar in the water columns of the studied mesocosms. Similarly, decay rates of viral targets were also alike in mesocosm water columns in relation to each other. The decay rates of FIB and sewage-associated markers were significantly faster in water s les compared to sediments in all three mesocosms. In the event of resuspension, FIB and marker genes from sediments can potentially recontaminate overlying waters. Thus, care should be taken when interpreting the occurrence of FIB and sewage-associated MST markers in water, which may have originated from sediments. The differential decay of these targets may also influence health outcomes and need to be considered in risk assessment models.
Publisher: MDPI AG
Date: 25-06-2018
DOI: 10.3390/W10070841
Publisher: MDPI AG
Date: 23-06-2021
DOI: 10.3390/PATHOGENS10070798
Abstract: In this study, we investigated the occurrence of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) RNA in primary influent (n = 42), secondary effluent (n = 24) and tertiary treated effluent (n = 34) collected from six wastewater treatment plants (WWTPs A–F) in Virginia (WWTP A), Florida (WWTPs B, C, and D), and Georgia (WWTPs E and F) in the United States during April–July 2020. Of the 100 wastewater s les analyzed, eight (19%) untreated wastewater s les collected from the primary influents contained SARS-CoV-2 RNA as measured by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assays. SARS-CoV-2 RNA were detected in influent wastewater s les collected from WWTP A (Virginia), WWTPs E and F (Georgia) and WWTP D (Florida). Secondary and tertiary effluent s les were not positive for SARS-CoV-2 RNA indicating the treatment processes in these WWTPs potentially removed SARS-CoV-2 RNA during the secondary and tertiary treatment processes. However, further studies are needed to understand the log removal values (LRVs) and transmission risks of SARS-CoV-2 RNA through analyzing wastewater s les from a wider range of WWTPs.
Publisher: American Society for Microbiology
Date: 15-03-2015
DOI: 10.1128/AEM.03851-14
Abstract: Pathogenic human viruses cause over half of gastroenteritis cases associated with recreational water use worldwide. They are relatively difficult to concentrate from environmental waters due to typically low concentrations and their small size. Although rapid enumeration of viruses by quantitative PCR (qPCR) has the potential to greatly improve water quality analysis and risk assessment, the upstream steps of capturing and recovering viruses from environmental water sources along with removing PCR inhibitors from extracted nucleic acids remain formidable barriers to routine use. Here, we compared the efficiency of virus recovery for three rapid methods of concentrating two microbial source tracking (MST) viral markers human adenoviruses (HAdVs) and polyomaviruses (HPyVs) from one liter tap water and river water s les on HA membranes (90 mm in diameter). S les were spiked with raw sewage, and viral adsorption to membranes was promoted by acidification (method A) or addition of MgCl 2 (methods B and C). Viral nucleic acid was extracted directly from membranes (method A), or viruses were eluted with NaOH and concentrated by centrifugal ultrafiltration (methods B and C). No inhibition of qPCR was observed for s les processed by method A, but inhibition occurred in river s les processed by B and C. Recovery efficiencies of HAdVs and HPyVs were ∼10-fold greater for method A (31 to 78%) than for methods B and C (2.4 to 12%). Further analysis of membranes from method B revealed that the majority of viruses were not eluted from the membrane, resulting in poor recovery. The modification of the originally published method A to include a larger diameter membrane and a nucleic acid extraction kit that could accommodate the membrane resulted in a rapid virus concentration method with good recovery and lack of inhibitory compounds. The frequently used strategy of viral absorption with added cations (Mg 2+ ) and elution with acid were inefficient and more prone to inhibition, and will result in underestimation of the prevalence and concentrations of HAdVs and HPyVs markers in environmental waters.
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.EXPPARA.2015.08.009
Abstract: The risk of human hookworm infections from land application of wastewater matrices could be high in regions with high hookworm prevalence. A rapid, sensitive and specific hookworm detection method from wastewater matrices is required in order to assess human health risks. Currently available methods used to identify hookworm ova to the species level are time consuming and lack accuracy. In this study, a real-time PCR method was developed for the rapid, sensitive and specific detection of canine hookworm (Ancylostoma caninum) ova from wastewater matrices. A. caninum was chosen because of its morphological similarity to the human hookworm (Ancylostoma duodenale and Necator americanus). The newly developed PCR method has high detection sensitivity with the ability to detect less than one A. caninum ova from 1 L of secondary treated wastewater at the mean threshold cycle (CT) values ranging from 30.1 to 34.3. The method is also able to detect four A. caninum ova from 1 L of raw wastewater and from ∼4 g of treated sludge with mean CT values ranging from 35.6 to 39.8 and 39.8 to 39.9, respectively. The better detection sensitivity obtained for secondary treated wastewater compared to raw wastewater and sludge s les could be attributed to s le turbidity. The proposed method appears to be rapid, sensitive and specific compared to traditional methods and has potential to aid in the public health risk assessment associated with land application of wastewater matrices. Furthermore, the method can be adapted to detect other helminth ova of interest from wastewater matrices.
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.WATRES.2019.02.003
Abstract: Bivalve molluscan shellfish grown in areas impacted by human faecal pollution are at risk of being contaminated with multiple enteric viruses. To minimise the public health risks associated with shellfish consumption, determining the presence of faecal contamination in shellfish and their growing waters is crucial. In this study, we evaluated the use of pepper mild mottle virus (PMMoV) as an indicator of human faecal contamination in oysters, mussels, cockles and shellfish growing waters in New Zealand. Using reverse transcription quantitative polymerase chain reaction (RT-qPCR) the presence, and where applicable, the concentration of PMMoV was determined in faeces from 11 different animal species, influent (untreated) wastewater, shellfish and shellfish growing waters. Non-human faecal s les (from seagull, Canada goose, black swan and dog) were RT-qPCR positive for PMMoV. The faecal source specificity of PMMoV was 0.83 (maximum value of 1) when 'detected but not quantifiable' (DNQ) values were used. However, when 'lower limit of quantification' (LLOQ) values were used, the specificity increased to 0.92. The PMMoV concentration in influent wastewater (n = 10) ranged from 6.3 to 7.7 log
Publisher: American Society for Microbiology
Date: 15-10-2015
DOI: 10.1128/AEM.02032-15
Abstract: In this study, host-associated molecular markers and bacterial 16S rRNA gene community analysis using high-throughput sequencing were used to identify the sources of fecal pollution in environmental waters in Brisbane, Australia. A total of 92 fecal and composite wastewater s les were collected from different host groups (cat, cattle, dog, horse, human, and kangaroo), and 18 water s les were collected from six sites (BR1 to BR6) along the Brisbane River in Queensland, Australia. Bacterial communities in the fecal, wastewater, and river water s les were sequenced. Water s les were also tested for the presence of bird-associated (GFD), cattle-associated (CowM3), horse-associated, and human-associated (HF183) molecular markers, to provide multiple lines of evidence regarding the possible presence of fecal pollution associated with specific hosts. Among the 18 water s les tested, 83%, 33%, 17%, and 17% were real-time PCR positive for the GFD, HF183, CowM3, and horse markers, respectively. Among the potential sources of fecal pollution in water s les from the river, DNA sequencing tended to show relatively small contributions from wastewater treatment plants (up to 13% of sequence reads). Contributions from other animal sources were rarely detected and were very small ( % of sequence reads). Source contributions determined via sequence analysis versus detection of molecular markers showed variable agreement. A lack of relationships among fecal indicator bacteria, host-associated molecular markers, and 16S rRNA gene community analysis data was also observed. Nonetheless, we show that bacterial community and host-associated molecular marker analyses can be combined to identify potential sources of fecal pollution in an urban river. This study is a proof of concept, and based on the results, we recommend using bacterial community analysis (where possible) along with PCR detection or quantification of host-associated molecular markers to provide information on the sources of fecal pollution in waterways.
Publisher: Elsevier BV
Date: 10-2020
Publisher: American Society for Microbiology
Date: 15-02-2016
DOI: 10.1128/AEM.03765-15
Abstract: Recreational and potable water supplies polluted with human wastewater can pose a direct health risk to humans. Therefore, sensitive detection of human fecal pollution in environmental waters is very important to water quality authorities around the globe. Microbial source tracking (MST) utilizes human fecal markers (HFMs) to detect human wastewater pollution in environmental waters. The concentrations of these markers in raw wastewater are considered important because it is likely that a marker whose concentration is high in wastewater will be more frequently detected in polluted waters. In this study, quantitative PCR (qPCR) assays were used to determine the concentrations of fecal indicator bacteria (FIB) Escherichia coli and Enterococcus spp., HFMs Bacteroides HF183, human adenoviruses (HAdVs), and polyomaviruses (HPyVs) in raw municipal wastewater influent from various climatic zones in Australia. E. coli mean concentrations in pooled human wastewater data sets (from various climatic zones) were the highest (3.2 × 10 6 gene copies per ml), followed by those of HF183 (8.0 × 10 5 gene copies per ml) and Enterococcus spp. (3.6 × 10 5 gene copies per ml). HAdV and HPyV concentrations were 2 to 3 orders of magnitude lower than those of FIB and HF183. Strong positive and negative correlations were observed between the FIB and HFM concentrations within and across wastewater treatment plants (WWTPs). To identify the most sensitive marker of human fecal pollution, environmental water s les were seeded with raw human wastewater. The results from the seeding experiments indicated that Bacteroides HF183 was more sensitive for detecting human fecal pollution than HAdVs and HPyVs. Since the HF183 marker can occasionally be present in nontarget animal fecal s les, it is recommended that HF183 along with a viral marker (HAdVs or HPyVs) be used for tracking human fecal pollution in Australian environmental waters.
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 10-2020
Publisher: Nepal Journals Online (JOL)
Date: 16-07-2018
DOI: 10.3126/JMCJMS.V6I1.20573
Abstract: Background and Objectives: Gastrointestinal infection is a major cause of diarrhea, anemia, malnutrition and responsible for reducing physical and mental development especially in children. This study aimed to investigate the prevalence of the intestinal pathogens in the slum-dwelling population in Kaski, Nepal.Material and Methods: A cross-sectional study was conducted in August-September 2012 in slum-dwelling community. Overall 166 human faecal s les were collected and examined using formal ether sedimentation method.Results: The prevalence of gastrointestinal infections in slum-dwelling population was found to be 24.1%. The magnitude of infection was higher (26.9%) among females compared to males. The difference was not statistically significant (P 0.05). The prevalence of infection was higher (37.0%, P 0.05) in Dalit group. Children (≤10 years) had higher rate of infection than older people. 22% subjects had single and 2.4% had multiple infections. In the overall population, 12.7% had G. lamblia followed by 5.4% Ascaris lumbricoides, 4.8% Hymenolepsis nana and 3.6% Trichuris trichuria. Conclusion: Gastrointestinal infections were common in the slum-dwelling populations. Lack of health education and safe drinking water contributed higher infection rate in the community. Increased exposure time to the contaminated water and gender disparity had influenced the rate of infection. Due to the semi-urban area with absence of moist soil, protozoan infection was prevalent than helminth infections.
Publisher: MDPI AG
Date: 19-04-2021
DOI: 10.20944/PREPRINTS202104.0481.V1
Abstract: Wastewater surveillance for pathogens using the reverse transcription-polymerase chain reaction (RT-PCR) is an effective, resource-efficient tool for gathering additional community-level public health information, including the incidence and/or prevalence and trends of coronavirus disease-19 (COVID-19). Surveillance of SARS-CoV-2 in wastewater may provide an early-warning signal of COVID-19 infections in a community. The capacity of the world& rsquo s environmental microbiology and virology laboratories for SARS-CoV-2 RNA characterization in wastewater is rapidly increasing. However, there are no standardized protocols nor harmonized quality assurance and quality control (QA/QC) procedures for SARS-CoV-2 wastewater surveillance. This paper is a technical review of factors that can lead to false-positive and -negative errors in the surveillance of SARS-CoV-2, culminating in recommendations and strategies that can be implemented to identify and mitigate these errors. Recommendations include, stringent QA/QC measures, representative s ling approaches, effective virus concentration and efficient RNA extraction, lification inhibition assessment, inclusion of s le processing controls, and considerations for RT-PCR assay selection and data interpretation. Clear data interpretation guidelines (e.g., determination of positive and negative s les) are critical, particularly during a low incidence of SARS-CoV-2 in wastewater. Corrective and confirmatory actions must be in place for inconclusive and/or potentially significant results (e.g., initial onset or reemergence of COVID-19 in a community). It will also be prudent to perform inter-laboratory comparisons to ensure results are reliable and interpretable for ongoing and retrospective analyses. The strategies that are recommended in this review aim to improve SARS-CoV-2 characterization for wastewater surveillance applications. A silver lining of the COVID-19 pandemic is that the efficacy of wastewater surveillance was demonstrated during this global crisis. In the future, wastewater will play an important role in the surveillance of a range of other communicable diseases.
Publisher: Elsevier BV
Date: 08-2021
Publisher: IWA Publishing
Date: 11-03-2022
DOI: 10.2166/WH.2022.285
Abstract: The occurrence of amoeba, Naegleria fowleri, in sediment s les from Lake Pontchartrain in Louisiana was investigated. This amoeba is pathogenic and can cause primary amoebic meningoencephalitis. In this study, quantitative polymerase chain reaction methods were used to test for the prevalence of Naegleria fowleri, HF183, and E. coli. N. fowleri was detected in 51.25% of our sediment s les. Illumina sequencing of sediment s les revealed ten different phyla, with Cyanobacteria being the most predominant at sites that generally presented with the highest median N. fowleri concentrations. N. fowleri was however strongly negatively correlated with HF183 (r = −0.859, p & 0.001). Whenever sediment E. coli concentrations were below 1.54 Log GC/g, there was only a 37.5% chance that N. fowleri would be detected in the same s le. When sediment E. coli concentrations exceeded 2.77 Log GC/g, the chances of detecting N. fowleri in the same s le increased to 90%, potentially suggesting predatory activity by the amoeba. The effect of temperature was observed to be different in relation to observed N. fowleri concentrations and detection rates. Although sediment s les collected during periods of higher temperatures had significantly lower mean N. fowleri concentrations (2.7 Log GC/g) compared to those collected at lower temperatures (3.7 Log GC/g, t(39) = 4.167, p & 0.001), higher N. fowleri detection rates in the overall s les were observed at higher temperatures (& .1 °C) than at lower temperatures (& .1 °C).
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.JES.2016.10.019
Abstract: A quantitative PCR (qPCR) assay was used to quantify Ancylostoma caninum ova in wastewater and sludge s les. We estimated the average gene copy numbers for a single ovum using a mixed population of ova. The average gene copy numbers derived from the mixed population were used to estimate numbers of hookworm ova in A. caninum seeded and unseeded wastewater and sludge s les. The newly developed qPCR assay estimated an average of 3.7×10
Publisher: Springer Science and Business Media LLC
Date: 15-06-2016
DOI: 10.1007/S11356-016-7039-9
Abstract: In this study, we have evaluated the efficacy of propidium monoazide quantitative polymerase chain reaction (PMA-qPCR) to differentiate between viable and non-viable Ancylostoma caninum ova. The newly developed method was validated using raw wastewater seeded with known numbers of A. caninum ova. Results of this study confirmed that PMA-qPCR has resulted in average of 88 % reduction (P < 0.05) in gene copy numbers for 50 % viable +50 % non-viable when compared with 100 % viable ova. A reduction of 100 % in gene copies was observed for 100 % non-viable ova when compared with 100 % viable ova. Similar reductions (79-80 %) in gene copies were observed for A. caninum ova-seeded raw wastewater s les (n = 18) collected from wastewater treatment plants (WWTPs) A and B. The newly developed PMA-qPCR method was applied to determine the viable ova of different helminths (A. caninum, A. duodenale, Necator americanus and Ascaris lumbricoides) in raw wastewater, human fecal and soil s les. None of the unseeded wastewater s les were positive for the above-mentioned helminths. N. americanus and A. lumbricoides ova were found in unseeded human fecal and soil s les. For the unseeded human fecal s les (1 g), an average gene copy concentration obtained from qPCR and PMA-qPCR was found to be similar (6.8 × 10(5) ± 6.4 × 10(5) and 6.3 × 10(5) ± 4.7 × 10(5)) indicating the presence of viable N. americanus ova. Among the 24 unseeded soil s les tested, only one was positive for A. lumbricoides. The mean gene copy concentration in the positively identified soil s le was 1.0 × 10(5) ± 1.5 × 10(4) (determined by qPCR) compared to 4.9 × 10(4) ± 3.7 × 10(3) (determined by PMA-qPCR). The newly developed PMA-qPCR methods were able to detect viable helminth ova from wastewater and soil s les and could be adapted for health risk assessment.
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.EXPPARA.2015.09.002
Abstract: Hookworm infection contributes around 700 million infections worldwide especially in developing nations due to increased use of wastewater for crop production. The effective recovery of hookworm ova from wastewater matrices is difficult due to their low concentrations and heterogeneous distribution. In this study, we compared the recovery rates of (i) four rapid hookworm ova concentration methods from municipal wastewater, and (ii) two concentration methods from sludge s les. Ancylostoma caninum ova were used as surrogate for human hookworm (Ancylostoma duodenale and Necator americanus). Known concentration of A. caninum hookworm ova were seeded into wastewater (treated and raw) and sludge s les collected from two wastewater treatment plants (WWTPs) in Brisbane and Perth, Australia. The A. caninum ova were concentrated from treated and raw wastewater s les using centrifugation (Method A), hollow fiber ultrafiltration (HFUF) (Method B), filtration (Method C) and flotation (Method D) methods. For sludge s les, flotation (Method E) and direct DNA extraction (Method F) methods were used. Among the four methods tested, filtration (Method C) method was able to recover higher concentrations of A. caninum ova consistently from treated wastewater (39-50%) and raw wastewater (7.1-12%) s les collected from both WWTPs. The remaining methods (Methods A, B and D) yielded variable recovery rate ranging from 0.2 to 40% for treated and raw wastewater s les. The recovery rates for sludge s les were poor (0.02-4.7), although, Method F (direct DNA extraction) provided 1-2 orders of magnitude higher recovery rate than Method E (flotation). Based on our results it can be concluded that the recovery rates of hookworm ova from wastewater matrices, especially sludge s les, can be poor and highly variable. Therefore, choice of concentration method is vital for the sensitive detection of hookworm ova in wastewater matrices.
Publisher: Nepal Journals Online (JOL)
Date: 08-03-2013
Abstract: Parasitic infection is common in indigenous community in low land of Nepal. Their life expectancy is well below in comparison to the other people. Kumal are disadvantaged group of people with low socio-economic condition. This study investigated helminthic infection in Kumal community in Gaidakot VDC, Chitwan district people. In this study 17% of total population of Kumal was selected and helminth parasitic eggs and larvae were detected by floatation method. Half of the study population had at least one helminthic parasite in their body. Hookworm was the most common parasites with 30.87% followed by Ascaris, Hymenolepsis, Trichuris, Strongyloide and Taenia with 16.10%, 6.04%, 3.35%, 2.68% and 2.01% respectively. Fourty years and older population were highly affected by helminths in both sexes. Single, double and multiple parasitic eggs also were recorded in the study population. Nepal Journal of Science and Technology Vol. 13, No. 2 (2012) 175-178 DOI: 0.3126/njst.v13i2.7731
Publisher: MDPI AG
Date: 31-05-2019
DOI: 10.3390/FOODS8060187
Abstract: Reports of norovirus infections associated with the consumption of contaminated bivalve molluscan shellfish negatively impact both consumers and commercial shellfish operators. Current virus recovery and PCR detection methods can be expensive and time consuming. Due to the lack of rapid, user-friendly and onsite/infield methods, it has been difficult to establish an effective virus monitoring regime that is able to identify contamination points across the production line (i.e., farm-to-plate) to ensure shellfish quality. The focus of this review is to evaluate current norovirus detection methods and discuss emerging approaches. Recent advances in omics-based detection approaches have the potential to identify novel biomarkers that can be incorporated into rapid detection kits for onsite use. Furthermore, some omics techniques have the potential to simultaneously detect multiple enteric viruses that cause human disease. Other emerging technologies discussed include microfluidic, aptamer and biosensor-based detection methods developed to detect norovirus with high sensitivity from a simple matrix. Many of these approaches have the potential to be developed as user-friendly onsite detection kits with minimal costs. However, more collaborative efforts on research and development will be required to commercialize such products. Once developed, these emerging technologies could provide a way forward that minimizes public health risks associated with shellfish consumption.
Publisher: IWA Publishing
Date: 14-12-2018
DOI: 10.2166/WST.2017.619
Abstract: Raw and partially treated wastewater has been widely used to maintain the global water demand. Presence of viable helminth ova and larvae in the wastewater raised significant public health concern especially when used for agriculture and aquaculture. Depending on the prevalence of helminth infections in communities, up to 1.0 × 103 ova/larvae can be presented per litre of wastewater and 4 gm (dry weight) of sludge. Multi-barrier approaches including pathogen reduction, risk assessment, and exposure reduction have been suggested by health regulators to minimise the potential health risk. However, with a lack of a sensitive and specific method for the quantitative detection of viable helminth ova from wastewater, an accurate health risk assessment is difficult to achieve. As a result, helminth infections are difficult to control from the communities despite two decades of global effort (mass drug administration). Molecular methods can be more sensitive and specific than currently adapted culture-based and vital stain methods. The molecular methods, however, required more and thorough investigation for its ability with accurate quantification of viable helminth ova/larvae from wastewater and sludge s les. Understanding different cell stages and corresponding gene copy numbers is pivotal for accurate quantification of helminth ova/larvae in wastewater s les. Identifying specific genetic markers including protein, lipid, and metabolites using multiomics approach could be utilized for cheap, rapid, sensitive, specific and point of care detection tools for helminth ova and larva in the wastewater.
Publisher: IWA Publishing
Date: 06-03-2017
DOI: 10.2166/WST.2017.142
Abstract: Accurate quantitative measurement of viable hookworm ova from environmental s les is the key to controlling hookworm re-infections in the endemic regions. In this study, the accuracy of three quantitative detection methods [culture-based, vital stain and propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR)] was evaluated by enumerating 1,000 ± 50 Ancylostoma caninum ova in the laboratory. The culture-based method was able to quantify an average of 397 ± 59 viable hookworm ova. Similarly, vital stain and PMA-qPCR methods quantified 644 ± 87 and 587 ± 91 viable ova, respectively. The numbers of viable ova estimated by the culture-based method were significantly (P & 0.05) lower than vital stain and PMA-qPCR methods. Therefore, both PMA-qPCR and vital stain methods appear to be suitable for the quantitative detection of viable hookworm ova. However, PMA-qPCR would be preferable over the vital stain method in scenarios where ova speciation is needed.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 08-2019
Publisher: Springer Science and Business Media LLC
Date: 13-08-2016
Publisher: Springer Science and Business Media LLC
Date: 30-03-2017
DOI: 10.1007/S11356-017-8858-Z
Abstract: Roof-harvested rainwater (RHRW) is an important alternative source of water that many island communities can use for drinking and other domestic purposes when groundwater and/or surface water sources are contaminated, limited, or simply not available. The aim of this pilot-scale study was to investigate current RHRW practices in American Samoa (AS) and to evaluate and compare the quality of water from common potable water sources including RHRW stored in tanks, untreated stream water, untreated municipal well water, and treated municipal tap water s les. S les were analyzed using culture-based methods, quantitative polymerase chain reaction (qPCR), and 16S licon sequencing-based methods. Based on indicator bacteria (total coliform and Escherichia coli) concentrations, the quality of RHRW was slightly lower than well and chlorinated tap water but exceeded that of untreated stream water. Although no Giardia or Leptospira spp. were detected in any of the RHRW s les, 86% of the s les were positive for Cryptosporidium spp. All stream water s les tested positive for Cryptosporidium spp. Opportunistic pathogens (Pseudomonas aeruginosa and Mycobacterium intracellulare) were also detected in the RHRW s les (71 and 21% positive s les, respectively). Several potentially pathogenic genera of bacteria were also detected in RHRW by licon sequencing. Each RHRW system was characterized by distinct microbial communities, 77% of operational taxonomic units (OTUs) were detected only in a single tank, and no OTU was shared by all the tanks. Risk of water-borne illness increased in the following order: chlorinated tap water/well water < RHRW < stream water. Frequent detection of opportunistic pathogens indicates that RHRW should be treated before use. Stakeholder education on RHRW system design options as well as on importance of regular cleaning and proper management techniques could improve the quality of the RHRW in AS.
Publisher: Springer Science and Business Media LLC
Date: 07-08-2018
DOI: 10.1007/S11356-018-2869-2
Abstract: The BioFire FilmArray
Publisher: American Society for Microbiology
Date: 15-07-2019
DOI: 10.1128/AEM.00641-19
Abstract: Large financial investments are required to remediate fecal contamination sources in waterways, and accurate results from field studies are crucial to build confidence in MST approaches. Host specificity and sensitivity are two main performance characteristics for consideration when choosing MST assays. Ongoing efforts for marker assay validation will improve interpretation of results and could shed light on patterns of occurrence in nontarget hosts that might explain the underlying drivers of cross-reaction of certain markers. For field applications, caution should be taken to choose appropriate MST marker genes and assays based on available host specificity and sensitivity data and background knowledge of the contaminating sources in the study area. Since many waterborne pathogens are viruses, employing both viral and bacterial markers in investigations could provide insight into contamination dynamics and ecological behavior in the environment. Therefore, combined usage of marker assays is recommended for more accurate and informative sewage contamination detection and fecal source resolution.
Location: New Zealand
No related grants have been discovered for Pradip Gyawali.