Wastewater-based epidemiology (WBE) has been demonstrated for its great potential in tracking of coronavirus disease 2019 (COVID-19) transmission among populations despite some inherent ...methodological limitations. These include non-optimized sampling approaches and analytical methods; stability of viruses in sewer systems; partitioning/retention in biofilms; and the singular and inaccurate back-calculation step to predict the number of infected individuals in the community. Future research is expected to (1) standardize best practices in wastewater sampling, analysis and data reporting protocols for the sensitive and reproducible detection of viruses in wastewater; (2) understand the in-sewer viral stability and partitioning under the impacts of dynamic wastewater flow, properties, chemicals, biofilms and sediments; and (3) achieve smart wastewater surveillance with artificial intelligence and big data models. Further specific research is essential in the monitoring of other viral pathogens with pandemic potential and subcatchment applications to maximize the benefits of WBE beyond COVID-19.
Antibiotic-resistant Enterococcus (ARE) are among leading causes of nosocomial infections worldwide. Enterococcus spp. are ubiquitous in sewage, which can contaminate surface waters via many ...pathways, providing a route of exposure for humans. This review focuses on ARE in marine and estuarine habitats, including marine animals. Phylogenetic confirmation of the genus Enterococcus and intermediate or full resistance to clinically relevant antibiotics were inclusion criteria. The proportion of resistant isolates varied greatly among antibiotics, for example, 24.2% for ampicillin and 2.4% for vancomycin. The water column contained the highest proportion of ARE observations (18.8%), followed by animal feces and tissues (14.8%), sediment (9.4%), and sand (2.0%). The proportion of multidrug-resistant isolates was the greatest in animal tissue and fecal samples, followed by water and sediments. This review indicates that clinically relevant ARE are present in marine/estuarine habitats and that animals may be important reservoirs.
•Review of antibiotic-resistant Enterococci (ARE) in marine environments.•ARE from water were most commonly resistant, followed by animals and sediment.•Animal fecal/tissue samples were the most common source of multidrug resistant ARE.
With wastewater surveillance being implemented worldwide to aid in managing coronavirus disease 2019 (COVID-19), there is a need to understand the fate of severe acute respiratory syndrome ...coronavirus 2 (SARS-CoV-2) in sewer systems. Here we employed a sewer reactor to investigate sorption, decay and persistence of SARS-CoV-2 RNA in sewers. RNA concentrations were positively correlated between wastewater liquid and suspended solids, and between wastewater mixture and sewer biofilms. We identified two roles of biofilms in mediating the fate of SARS-CoV-2 RNA. Firstly, biofilms could affect RNA in-sewer stability. This impact could be limited in typical sewer systems with high COVID-19 prevalence, as estimated RNA loss was relatively small. However, in low-case settings, in-sewer RNA decay could affect detectability and precision of analysis, particularly over long hydraulic retention times before sample collection. The second role of biofilms is a reservoir for accumulating, retaining and distributing SARS-CoV-2 RNA under hydraulic changes, which could lead to prolonged virus presence and affect wastewater surveillance interpretation.Understanding the fate of the severe acute respiratory syndrome coronavirus 2 RNA in sewage is essential to develop reliable wastewater surveillance. Research employing a sewer reactor shows that biofilms affect the RNA stability and can act as reservoirs for accumulating, retaining and distributing severe acute respiratory syndrome coronavirus 2 RNA under hydraulic changes.
This chapter outlines the application of fecal source tracking (FST) methods in waterways in Australia and New Zealand. FST methods used in the case studies include biochemical fingerprinting (BF), ...antibiotic resistance analysis (ARA), anaerobic bacterial genetic markers, toxin genetic markers, viral markers, fluorescent whitening agents (FWAs), and fecal sterols. These methods were predominantly used to identify human fecal pollution in receiving waters sourced from defective septic systems or discharges from sewage treatment plants (STPs). In some cases, these methods were also used to identify the sources of elevated levels of fecal indicator bacteria in catchment waters. The earlier case studies employed library-dependent FST methods, whereas the recent studies focused on validation and application of library-independent methods. Several case studies reported the presence of human fecal pollution in environmental waters and suggested that genetic markers are appealing because of their high specificity and sensitivity to differentiate and detect human and animal fecal pollution. Few case studies also used a combination of methods and suggested that such an approach can compensate uncertainty when one marker fails to produce satisfactory results. However little is known regarding the persistence of these markers in relation to fecal indicators and pathogens. More research is required regarding the behaviors of these markers in the environments.
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