Beach sand may act as a reservoir for numerous microorganisms, including enteric pathogens. Several of these pathogens originate in human or animal feces, which may pose a public health risk. In ...August 2019, high levels of fecal indicator bacteria (FIB) were detected in the sand of the Azorean beach Prainha, Terceira Island, Portugal. Remediation measures were promptly implemented, including sand removal and the spraying of chlorine to restore the sand quality. To determine the source of the fecal contamination, during the first campaign, supratidal sand samples were collected from several sites along the beach, followed by microbial source tracking (MST) analyses of Bacteroides marker genes for five animal species, including humans. Some of the sampling sites revealed the presence of marker genes from dogs, seagulls, and ruminants. Making use of the information on biological sources originating partially from dogs, the municipality enforced restrictive measures for dog-walking at the beach. Subsequent sampling campaigns detected low FIB contamination due to the mitigation and remediation measures that were undertaken. This is the first case study where the MST approach was used to determine the contamination sources in the supratidal sand of a coastal beach. Our results show that MST can be an essential tool to determine sources of fecal contamination in the sand. This study shows the importance of holistic management of beaches that should go beyond water quality monitoring for FIB, putting forth evidence for beach sand monitoring.
The use of recycled or reclaimed water for direct or indirect potable uses is increasing because of water scarcity. Wastewater contains pathogens that are capable of causing infections in humans. ...Among the microbial pathogens, viruses pose significant human health risks because of their high environmental persistence and low infectious doses. Routine monitoring of pathogenic viruses is challenging, time-consuming, and expensive. Moreover, the concentrations of most pathogenic viruses are not stable in wastewater throughout the year. As an alternative, viral indicators can be used to predict the presence, behavior, and removal of viral pathogens through wastewater treatment processes. This article highlights the characteristics of various viral indicators, and their usefulness as a proxy for the log reduction of pathogenic viruses for recycled water scheme. Concentrations of indicator viruses, such as pepper mild mottle virus and emerging crAssphage, are 2–3 orders of magnitude greater in untreated sewage than those of bacteriophages and other viral indicators. However, more research is needed for their comparative log reduction with pathogenic viruses. Developing effective methods to determine virus concentrations, the ability to culture indicator viruses, and new detection tools will enhance the application of indicator viruses in water recycling.
Potable and non-potable uses of roof-harvested rainwater (RHRW) are increasing due to water shortages. To protect human health risks, it is important to identify and quantify disease-causing ...pathogens in RHRW so that appropriate treatment options can be implemented. We used a microfluidic quantitative PCR (MFQPCR) system for the quantitative detection of a wide array of fecal indicator bacteria (FIB) and pathogens in RHRW tank samples along with culturable FIB and conventional qPCR analysis of selected pathogens. Among the nine pathogenic bacteria and their associated genes tested with the MFQPCR, 4.86 and 2.77% samples were positive for
Legionella pneumophila
and
Shigella
spp., respectively. The remaining seven pathogens were absent. MFQPCR and conventional qPCR results showed good agreement. Therefore, direct pathogen quantification by MFQPCR systems may be advantageous for circumstances where a thorough microbial analysis is required to assess the public health risks from multiple pathogens that occur simultaneously in the target water source.
Abstract
The impacts of nucleic acid-based methods - such as PCR and sequencing - to detect and analyze indicators, genetic markers or molecular signatures of microbial faecal pollution in ...health-related water quality research were assessed by rigorous literature analysis. A wide range of application areas and study designs has been identified since the first application more than 30 years ago (>1100 publications). Given the consistency of methods and assessment types, we suggest defining this emerging part of science as a new discipline: genetic faecal pollution diagnostics (GFPD) in health-related microbial water quality analysis. Undoubtedly, GFPD has already revolutionized faecal pollution detection (i.e., traditional or alternative general faecal indicator/marker analysis) and microbial source tracking (i.e., host-associated faecal indicator/marker analysis), the current core applications. GFPD is also expanding to many other research areas, including infection and health risk assessment, evaluation of microbial water treatment, and support of wastewater surveillance. In addition, storage of DNA extracts allows for biobanking, which opens up new perspectives. The tools of GFPD can be combined with cultivation-based standardized faecal indicator enumeration, pathogen detection, and various environmental data types, in an integrated data analysis approach. This comprehensive meta-analysis provides the scientific status quo of this field, including trend analyses and literature statistics, outlining identified application areas, and discusses the benefits and challenges of nucleic acid-based analysis in GFPD.
The proposed discipline of genetic faecal pollution diagnostics helps addressing complex water, sanitation, and human health-related issues: this systematic review elucidates application areas, key research questions and study designs from over 1100 scientific articles and provides critical insights and conclusions.
Monitoring for SARS-CoV-2 RNA in wastewater through the process of wastewater-based epidemiology provides an additional surveillance tool, contributing to community-level screening and prevention ...efforts as these measurements have preceded disease cases in some instances. Numerous detections of SARS-CoV-2 RNA have been reported globally using various methods, demonstrating the technical feasibility of routine monitoring. However, to reliably interpret data produced from these efforts for informing public health interventions, additional quality control information and standardization in sampling design, sample processing, and data interpretation and reporting are needed. This review summarizes published studies of SARS-CoV-2 RNA detection in wastewater as well as available information regarding sample concentration, extraction, and detection methods. The review highlights areas for potential standardization including considerations related to sampling time and frequency relative to peak fecal loading times; inclusion of appropriate information on sample collection points; sample volume collected; transport and storage conditions; sample concentration procedures; RNA extraction process and performance; effective sample volumes; recovery efficiency testing; PCR inhibition; process controls throughout sample collection and processing; and PCR standard curve performance. Researchers are advised to follow the Minimum Information for Publication of Quantitative Real-Time PCR guidelines. Adhering to these recommendations will enable robust interpretation of wastewater monitoring results and improved inferences regarding the relationship between monitoring results and disease cases.
Abstract
A broad body of literature has been published regarding roof-harvested rainwater quality around the world. In particular, the presence of fecal indicator bacteria and pathogenic ...microorganisms has raised concerns regarding the acceptability of rainwater for potable and non-potable uses. As the use of molecular assays has improved understanding of the diverse microbial communities present in rainwater tanks and their role in providing benefits or harm to human health, a comprehensive review is needed to summarize the state of the science in this area. To provide a summary of microbial contaminants in rainwater tanks and contextual factors, a comprehensive review was conducted here to elucidate the uses of rainwater, factors affecting water quality, concentrations of fecal indicators and pathogens, the attribution of pathogens to host sources using microbial source tracking, microbial ecology, human health risks determined using epidemiological approaches and quantitative microbial risk assessment, and treatment approaches for mitigating risks. Research gaps were identified for pathogen concentration data, microbial source tracking approaches for identifying the sources of microbial contamination, limitations to current approaches for assessing viability, treatment, and maintenance practices. Frameworks should be developed to assess and prioritize these factors in order to optimize public health promotion for roof-harvested rainwater.
•Storms promoted the ARG abundances by introducing the input of ARGs.•HGT potential for ARGs among bacteria was promoted due to the storm.•Bio-interactions among ARGs and bacteria were promoted ...during the storm.•Different factors drove ARG and bacterial communities differently.
Antibiotic-resistance genes (ARGs) and resistant bacteria (ARB) are abundant in stormwater that could cause serious infections, posing a potential threat to public health. However, there is no inference about how stormwater contributes to ARG profiles as well as the dynamic interplay between ARGs and bacteria via vertical gene transfer (VGT) or horizontal gene transfer (HGT) in urban water ecosystems. In this study, the distribution of ARGs, their host communities, and the source and community assembly process of ARGs were investigated in Yundang Lagoon (China) via high-throughput quantitative PCR, 16S rRNA gene amplicon sequencing, and application of SourceTracker before, after and recovering from an extreme precipitation event (132.1 mm). The abundance of ARGs and mobile genetic elements (MGEs) was the highest one day after precipitation and then decreased 2 days after precipitation and so on. Based on SourceTracker and NMDS analysis, the ARG and bacterial communities in lagoon surface water from one day after precipitation were mainly contributed by the wastewater treatment plant (WWTP) influent and effluent. However, the contribution of WWTP to ARG communities was minor 11 days after the precipitation, suggesting that the storm promoted the ARG levels by introducing the input of ARGs, MGEs, and ARB from point and non-point sources, such as sewer overflow and land-applied manure. Based on a novel microbial network analysis framework, the contribution of positive biological interactions between ARGs and MGEs or bacteria was the highest one day after precipitation, indicating a promoted VGT and HGT for ARG dissemination. The microbial networks deconstructed 11 days after precipitation, suggesting the stormwater practices (e.g., tide gate opening, diversion channels, and pumping) alleviated the spread of ARGs. These results advanced our understanding of the distribution and transport of ARGs associated with their source in urban stormwater runoff.
Roof-harvested rainwater (RHRW) has been used as an alternative source of water in water scarce regions of many countries. The microbiological and chemical quality of RHRW has been questioned due to ...the presence of bacterial and protozoan pathogens. However, information on the occurrence of pathogenic amoeba in RHRW tank samples is needed due to their health risk potential and known associations with opportunistic pathogens. Therefore, this study aims to determine the quantitative occurrence of
Naegleria fowleri
in RHRW tank samples from Southeast Queensland (SEQ), Australia (AU), and the Kleinmond Housing Scheme located in Kleinmond, South Africa (SA). In all, 134 and 80 RHRW tank samples were collected from SEQ, and the Kleinmond Housing Scheme, Western Cape, SA, respectively. Quantitative PCR (qPCR) assays were used to measure the concentrations of
N. fowleri
, and culture-based methods were used to measure fecal indicator bacteria (FIB)
Escherichia coli
(
E. coli
) and
Enterococcus
spp. Of the 134 tank water samples tested from AU, 69 and 62.7% were positive for
E. coli
, and
Enterococcus
spp., respectively. For the SA tank water samples, FIB analysis was conducted for samples SA-T41 to SA-T80 (
n
= 40). Of the 40 samples analyzed from SA, 95 and 35% were positive for
E. coli
and
Enterococcus
spp., respectively. Of the 134 water samples tested in AU, 15 (11.2%) water samples were positive for
N. fowleri
, and the concentrations ranged from 1.7 × 10
2
to 3.6 × 10
4
gene copies per 100 mL of water. Of the 80 SA tank water samples screened for
N. fowleri
, 15 (18.8%) tank water samples were positive for
N. fowleri
and the concentrations ranged from 2.1 × 10
1
to 7.8 × 10
4
gene copies per 100 mL of tank water. The prevalence of
N. fowleri
in RHRW tank samples from AU and SA thus warrants further development of dose-response models for
N. fowleri
and a quantitative microbial risk assessment (QMRA) to inform and prioritize strategies for reducing associated public health risks.
This study evaluated ten nucleic acid extraction protocols (EP1 to EP10) for measuring five endogenous antibiotic resistance genes (ARGs) in four aircraft wastewater samples (AWW1 to AWW4). The ...targeted ARGs, including bla
, bla
, ermB, qnrS, and tetA, encompassed highly and minimally abundant ARGs. TetA and ermB were consistently detected across four aircraft wastewater samples using the DNeasy Blood and Tissue Kit and the AllPrep PowerViral DNA/RNA kit. QnrS displayed high detection rates with specific extraction protocols and aliquot volumes. Concentrations of ARGs varied across aircraft wastewater samples, with differing extraction protocols influencing quantitative results. The concentrations of tetA, ermB, and qnrS in AWW1 were distinct, while AWW2 to AWW4 exhibited a broader range for tetA, ermB, qnrS, bla
, and bla
. EP1 consistently produced the highest concentrations for several ARGs. Collective data analysis revealed varying ARG concentrations across the ten extraction protocols, suggesting the importance of careful extraction protocol selection in ARG monitoring in aircraft wastewater samples. Based on the results, we suggest that a small sample volume (as low as 0.2 mL) may be sufficient for ARG characterization in aircraft wastewater samples. The findings also emphasize the need for considering toilet paper removal without compromising nucleic acid extraction efficiency. The study highlights promising prospects for aircraft wastewater monitoring of ARGs, calling for further investigation into the import and spread of unique ARGs through transport hubs.
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