Viruses In Water Research Articles

Detection of human enteric viruses in water and shellfish samples collected in Sicily (Italy)

Detection of human enteric viruses in water and shellfish samples collected in Sicily (Italy)

Comparative Study of Two Methods of Enteric Virus Detection and Enteric Virus Relationship with Bacterial Indicator in Poyang Lake, Jiangxi, China.

Currently, water contaminated with fecal matter poses a threat to public health and safety. Thus, enteric viruses are tested for as a part of water quality indicator assays; however, enteric viruses have not yet been listed in the criteria. Effective and sensitive methods for detecting enteric viruses are required in order to increase water safety. This study utilized enteric viruses as possible alternative indicators of water quality to examine fresh water in six sites in Poyang Lake, Nanchang, Jiangxi Province. The presence of norovirus geno-groups II (NoV GII), enteroviruses (EoV) and adenoviruses (AdV) were determined using Tianjin’s protocol and Hawaii’s protocol during a six month period from 2016–2017. The former used an electropositive material method for viral concentration and Taqman-q reverse transcription polymerase chain reaction (RT-PCR) to detect enteric viruses; while the latter used a filtration-based method for viral concentration and RT-PCR for enteric virus detection. There is a statistically significant difference between Tianjin’s method and Hawaii’s method for the detection of enteric viruses, such as NoV GII, EoV, and AdV (n = 36, p < 0.001). The enteric viruses showed no significant positive correlation with bacteria indicators (n = 36, p > 0.05). These data stress the need for additional indicators when establishing water quality systems, and the possibility of using enteric viruses as water quality indicators. It has become essential to improve shortcomings in order to search for an adequate method to detect enteric viruses in water and to implement such method in water quality monitoring.

Surveillance of Enteric Viruses and Thermotolerant Coliforms in Surface Water and Bivalves from a Mangrove Estuary in Southeastern Brazil.

This study was conducted to evaluate the microbiological quality of a mangrove estuary in the Vitória Bay region, Espírito Santo, Brazil. We analyzed the presence and concentration of enteric viruses and thermotolerant coliforms in water, mussels (Mytella charruana and Mytella guyanensis), and oysters (Crassostrea rhizophorae), collected over a 13-month period. Human adenovirus, rotavirus A (RVA), and norovirus genogroup II were analyzed by quantitative PCR. The highest viral load was found in RVA-positive samples with a concentration of 3.0 × 104genome copies (GC)L-1 in water samples and 1.3 × 105GCg-1 in bivalves. RVA was the most prevalent virus in all matrices. Thermotolerant coliforms were quantified as colony-forming units (CFU) by the membrane filtration method. The concentration of these bacteria in water was in accordance with the Brazilian standard for recreational waters (< 250CFU 100mL-1) during most of the monitoring period (12 out of 13months). However, thermotolerant coliform concentrations of 3.0, 3.1, and 2.6 log CFU 100g-1 were detected in M. charruana, M. guyanensis, and C. rhizophorae, respectively. The presence of human-specific viruses in water and bivalves reflects the strong anthropogenic impact on the mangrove and serves as an early warning of waterborne and foodborne disease outbreaks resulting from the consumption of shellfish and the practice of water recreational activities in the region.

Wastewater as an Indicator of Virus Circulation among Population of Dnipropetrovsk Oblast, Ukraine

ObjectiveThe purpose of the study was to confirm the hypothesis of possible intestinal viruses circulation in wastewater in Dnipropetrovsk Oblast, Ukraine.IntroductionThe main reservoir of intestinal viruses in the environment is human feces and contaminated wastewater. Sewage contamination preconditions further contamination of surface water serving as a source of water supply [2,7,8]. High resistance to physical and biological exposures ensures long-term survival of the viruses in water with various type and level of contaminants, especially in sewage. Detection of enteroviruses of a specific serotype in sewage indicates a significant number of people releasing the virus with feces [1,2]. There are two peaks of enteroviruses concentration in sewage: in January-April, and in June-September [8]. Sewage testing for enteroviruses is one of effective methods for their detection and risk assessment [3]. European region, including Ukraine, is recognized as free from of wild polioviruses, and a systematic study of sewage samples is important for identifying the possibilities of their "silent" circulation [6].MethodsWastewater samples from large sewerage collectors, sewage wells of infectious departments, city hospitals and district sewerage networks of Dnipropetrovsk Oblast were tested in 2007-2017 (39-64 samples monthly in the points are determined by the national regulations [7]). Gauze tampons (Moore's method) were used to collect wastewater [8]. In addition, samples were collected from wastewater flow into 1-liter sterile bottle with a sampler. Concentration was carried out using Enterosgel (hydroxyl methyl silicic acid) with high adsorption capacity [7]. The supernatant after all the concentration steps was used for culture on cell cultures RD, HEP-2, L20B [4,7,8].In the presence of cytopathic action in RD cells, culture liquid was inoculated into L20B cells to detect clear cytopathic activity. Culture liquids were investigated to identify enteroviruses in neutralization reaction. In HEP-2, cytopathic effects were observed in the form of clusters of different sizes cells, "grape clusters", which indicated the presence of adenoviruses. Adenoviruses were confirmed by immunochromatographic tests for adenovirus antigens "Cito Test Adeno" Pharmasko, Ukraine).ResultsDuring 10 years, 150 viruses were isolated, 2 of them were a mixture of polioviruses. The frequency of detection of enteroviruses (including polioviruses) and adenoviruses was 2.5% (Tab 1).The isolated strains of enteroviruses, including polioviruses, were sent for confirmation the Public Health Center of the Ministry of Health of Ukraine and Regional WHO polio reference laboratories (Moscow and Helsinki). All polio strains were attributed to the vaccine strain Sabin. Also, the result Coxsackie viruses B typing was confirmed.ConclusionsThe data testify to presence of Picornaviridae (polioviruses, Coxsackie B, non-polio enteroviruses (NPEVs), and Adenoviridae in the wastewater in Dnipropetrovsk Oblast, Ukraine. The typical composition of viruses was not constant. Types 1, 2 polioviruses (Sabin) were occasionally isolated from wastewater. Type 2 polioviruses (Sabin) were isolated only in 2015. In 2009, 2012-2014, 2017, polioviruses did not stand out. Polioviruses isolation is associated with mass immunization of children against polioviruses carried out to maintain polio-free status of the country. In average, 150,000 children are vaccinated annually. Oral poliomyelitis vaccine (OPV) produced in Russia, France, Belgium was used in 2007-2017 (attenuated Sabin strains, 1,2,3 types). From April 2016, Ukraine refused to use trivalent OPV and switched to bivalent vaccine (Sabin strains, types 1 and 2).Sewage testing for polioviruses and their differentiation at WHO National and Regional Centers for Polio Diagnosis ensures a system for monitoring of possible "silent" circulation [6]. Sewage testing using cell cultures is one of the most affordable, effective and reliable methods for controlling the presence of viruses in the environment [4,7,8]. RD and L20B cell lines are useful for poliovirus isolation from sewage [4].In addition to polioviruses, 1,2,3 types Coxsackie viruses B were isolated from wastewater samples. However, starting from 2013, Coxsackie viruses were isolated only in sporadic cases (Cox.vir.B5). In 2007-2011, NPEVs were isolated in some cases. Because polio is on the verge of eradication, more attention should be paid to study of NPEVs [5]. For 10 years, adenoviruses were isolated, which are well preserved in wastewater [1]. The maximum number of adenoviruses was isolated in 2014.

Quantitative PCR-based identification of enteric viruses contaminating fresh produce and surface water used for irrigation in Egypt.

Fresh produce irrigated with surface water that may contain pathogens such as enteric viruses can lead to outbreaks of foodborne viral illnesses. In the current study, we performed real-time PCR (qPCR) to monitor the presence of enteric viruses such as human adenoviruses (HAdVs), hepatitis A virus (HAV), rotavirus group A (RVA), and norovirus GI (NoV GI) in surface water and fresh produce that were grown using this surface water in Egypt. Samples were collected on four occasions from different sites located in the Delta and in Greater Cairo, Egypt. Of the 32 water samples and 128 fresh produce samples, 27/32 (84.3%) and 99/128 (77.3%), respectively, were positive for at least one virus. HAdV (30/32) with a mean viral load = 1.5 × 107 genome copies/L (GC/L) was the most commonly detected virus in water, followed by RVA (16/32, with a mean viral load = 2.7 × 105 GC/L), HAV (11/32, with a mean viral load = 1.2 × 104 GC /L), and NoV GI (10/32, with a mean viral load = 3.5 × 103 GC/L). Additionally, HAdV (71/128, with a mean viral load = 9.8 × 105 GC/g) was also the most commonly detected virus in the fresh produce, followed by NoV GI (43/128, with a mean viral load = 4.5 × 103 GC/g), HAV (33/128, with a mean viral load = 6.4 × 103 GC/g), and RVA (25/128, with a mean viral load = 1.5 × 104 GC/g). Our results indicate that fresh produce may be contaminated with a wide range of enteric viruses, and these viruses may originate from virus-contaminated irrigation water. Moreover, this fresh produce may serve as a potential vector for the transmission of viral foodborne illnesses. These findings are important for future risk assessment analysis related to water/foodborne viruses. Graphical abstract . Please provide caption for Graphical AbstractGraphical abstract showing sample collection and processing.

Cold Atmospheric Plasma as a Novel Method for Inactivation of Potato Virus Y in Water Samples

While one of the biggest problems we are facing today is water scarcity, enormous quantities of water are still being used in irrigation. If contaminated, this water can act as an effective pathway for the spread of disease-causing agents, like viruses. Here, we present a novel, environmentally friendly method known as cold atmospheric plasma for inactivation of viruses in water used in closed irrigation systems. We measured the plasma-mediated viral RNA degradation as well as the plasma-induced loss of viral infectivity using potato virus Y as a model virus due to its confirmed water transmissibility and economic as well as biological importance. We showed that only 1 min of plasma treatment is sufficient for successful inactivation of viruses in water samples with either high or low organic background. The plasma-mediated inactivation was efficient even at markedly higher virus concentrations than those expected in irrigation waters. Obtained results point to reactive oxygen species as the main mode of viral inactivation. Our laboratory-scale experiments confirm for the first time that plasma has an excellent potential as the eukaryotic virus inactivation tool for water sources and could thus provide a cost-effective solution for irrigation mediated plant virus transmission. The outstanding inactivation efficiency demonstrated by plasma treatments in water samples offers further expansions of its application to other water sources such as reused wastewater or contaminated drinking waters, as well as other plant, animal, and human waterborne viruses, ultimately leading to the prevention of water scarcity and numerous human, animal, and plant infections worldwide.

Confirming the need for virus disinfection in municipal subsurface drinking water supplies

Enteric viruses pose the greatest acute human health risks associated with subsurface drinking water supplies, yet quantitative risk assessment tools have rarely been used to develop health-based targets for virus treatment in drinking water sourced from these supplies. Such efforts have previously been hampered by a lack of consensus concerning a suitable viral reference pathogen and dose-response model as well as difficulties in quantifying pathogenic viruses in water. A reverse quantitative microbial risk assessment (QMRA) framework and quantitative polymerase chain reaction data for norovirus genogroup I in subsurface drinking water supplies were used herein to evaluate treatment needs for such water supplies. Norovirus was not detected in over 90% of samples, which emphasizes the need to consider the spatially and/or temporally intermittent patterns of enteric pathogen contamination in subsurface water supplies. Collectively, this analysis reinforces existing recommendations that a minimum 4-log treatment goal is needed for enteric viruses in groundwater in absence of well-specific monitoring information. This result is sensitive to the virus dose-response model used as there is approximately a 3-log discrepancy among virus dose-response models in the existing literature. This emphasizes the need to address the uncertainties and lack of consensus related to various QMRA modelling approaches and the analytical limitations that preclude more accurate description of virus risks.

'Don't put your head under water': enteric viruses in Brazilian recreational waters.

Like in many other countries, virologic analyses are not routinely performed in Brazil in monitoring water quality for recreational purposes. We surveyed current research regarding viral contamination of recreational water environments in Brazil. Among the enteric viruses studied in Brazilian recreational waters, we highlight adenoviruses, rotaviruses, enteroviruses and noroviruses. Although there has been relatively little research on outbreaks related to bathing in recreational water environments in Brazil, noroviruses and adenoviruses are the viruses that are most often related to outbreaks. Better surveillance of the occurrence of enteric viruses in water could improve the assessment of risk to human health as well as indicate the sources of contamination and thus demonstrate the importance of adequate environmental sanitation.

Virus and bacteria inactivation by CO2 bubbles in solution

The availability of clean water is a major problem facing the world. In particular, the cost and destruction caused by viruses in water remains an unresolved challenge and poses a major limitation on the use of recycled water. Here, we develop an environmentally friendly technology for sterilising water. The technology bubbles heated un-pressurised carbon dioxide or exhaust gases through wastewater in a bubble column, effectively destroying both bacteria and viruses. The process is extremely cost effective, with no concerning by-products, and has already been successfully scaled-up industrially.

Colloid chemistry pitfall for flow cytometric enumeration of viruses in water

Flow cytomtery (FCM) has become a standard approach to enumerate viruses in water research. However, the nature of the fluorescent signal in flow cytometric analysis of water samples and the mechanism of its formation, have not been addressed for bacteriophages expected in wastewaters. Here we assess the behaviour of fluorescent DNA-staining dyes in aqueous solutions, as well as sensitivity and accuracy of FCM for enumeration of DNA-stained model bacteriophages λ, P1, and T4. We demonstrate that in aqueous systems fluorescent dyes form a self-stabilized (pseudolyophilic) emulsion of auto-fluorescing colloid particles. Sample shaking and addition of surfactants enhance auto-fluorescence due to increased dispersion and, in the presence of surfactants, stabilization of the dye emulsion. Bacteriophages with genome sizes <100 kbp (i.e. λ & P1) did not generate a distinct population signal to be detected by one of the most sensitive FCM instruments available (BD LSR Fortessa™ X-20), whereas the larger T4 bacteriophage was resolved as a distinct population of events. These results indicate that the use of fluorescent dyes for bacteriophage enumeration by flow cytometry can produce false positive signals and lead to wrong estimation of total virus counts by misreporting colloid particles as virions, depending on instrument sensitivity.

Survey on Nanotechnology

Nanotechnology is a field where scientific knowledge and ideas emanating from the sub-atomic, atomic and molecular levels are applied in the manufacture of new and smart materials. Nanotechnology makes use of the novel properties exhibited by materials in the nanoscale. Nanocrystalline materials have microscopic grain sizes of up to 100 nm with remarkably distinct optical, electrical, chemical, mechanical properties different from those of bulk materials. Nanoparticles can be used to develop materials with unique properties since the number of atoms on the surface of a particle in the nanoscale is comparable to that inside the particle. Hence in order to meet the advanced technological demands in the areas such as electronics, catalysis, ceramics, magnetic data storage, structural components etc., it is important to make use of materials in the nanometer scale. Nanotechnology is a rapidly growing field of science which encompasses researchers and scientists from the areas of biology, chemistry, engineering, materials science, and physics. This technology provides the basis for research and manufacture of materials in the 21st century. In addition, this interdisciplinary technology will provide a strong platform for the growth of the pharmaceutical industry, medical diagnosis, materials industry and the overall economy of the country which will eventually enhance the creation of job opportunities, food security, good health and affordable housing in line with the government’s “big four” agenda. It promises improved efficiency in ICT equipment used in computing, data storage (chips) and communications (fiber optics). It can be used to develop renewable energy sources such as solar cells and panels. It can also be utilized to synthesize filters that can be used to get rid of pollutants; contaminants, harmful salts and viruses in water and sewerage systems and for the diagnosis and treatment of diseases including cancer and to restore damaged human organs or tissues using engineered tissue.

Ferrihydrite treatment to mitigate inhibition of RT-qPCR virus detection from large-volume environmental water samples

Molecular assays are currently the most widely used method to quantify pathogenic viruses in water; however, their performance is often disrupted by matrices present in environmental samples. The present study used ferrihydrite (Fh) treatment to mitigate inhibition of RT-qPCR virus detection from environmental water concentrates. Fh treatment was performed to improve the detection of spiked Aichi virus 1 (AiV) and Qβ bacteriophage (Qβ) in commercial humic acids and seawater concentrates. The optimal Fh doses were found to be 200, 500, and 1000 mgFe/L for humic acid concentrates at UV254 of 1.5, 3.0, and 6.0 cm−1 respectively, whereas this value was 1000 mgFe/L for the seawater concentrates at UV254 of 1.5 cm−1. At these optimal doses, the recoveries of spiked AiV and Qβ ranged from 2% to 12% in the humic acid and seawater concentrates, respectively. In addition, high levels of indigenous viruses (including AiV ≥ 2.81 log10 copies/mL and pepper mild mottle virus ≥ 2.77 log10 copies/mL) were detected from seawater concentrates after Fh treatment, while none were detected without Fh treatment. Fh treatment effectively mitigated the inhibitive effects from environmental water samples.

Chlorine inactivation of coxsackievirus B5 in recycled water destined for non-potable reuse.

Currently guidelines for disinfection of water with free chlorine, while primarily developed for potable water, are often used for virus disinfection of nitrified recycled water of >1 NTU (Nephelometric Turbidity Unit). More information is needed on the disinfection efficacy of free chlorine for viruses in waters of varying turbidity and pH due to significant reuse of treated wastewater of varying quality. In this study, disinfection efficacy in nitrified/denitrified activated sludge treated wastewater was investigated for coxsackievirus B5 (CB5), an enterovirus known to be highly resistant to free chlorine. The required chlorine contact times (CT) values (mg.min/L) for inactivation of CB5 were established in treated wastewater at 10 °C and of varying turbidity (0.2, 2, 5 and 20 NTU) and pH (7, 8 and 9). CTs were calculated to achieve 1 to 4 log10 inactivation. Robust data is presented in support of the chlorine CT values required to inactivate a chlorine-resistant virus in a range of turbidities and pHs in treated wastewaters. The testing method used a conservative approach and the data presented have been used to develop the free chlorine virus inactivation guildelines for recycled water in Victoria and South Australia, Australia.

Two-Step Concentration of Complex Water Samples for the Detection of Viruses.

The accurate detection and quantification of pathogenic viruses in water is essential to understand and reduce the risk of human infection. This paper describes a two-step method suitable for concentrating viruses in water and wastewater samples. The method involves a tangential flow ultrafiltration step that reduces the sample volume of 1–10 L to approximately 50 mL, followed by secondary precipitation using polyethylene glycol 6000, which reduces the volume to 1–4 mL. For method validation, water samples were spiked with different concentrations of enteric viruses, and viral recovery in the concentrates exceeded 10% in all experiments. The method is suitable for water samples with high and low salinity and turbidity, allowing an accurate comparison of viral titers in a diverse range of water types. Furthermore, the method has the potential to concentrate other pathogens, e.g., bacteria or protozoa. Hence, the use of this method can improve the holistic assessment of risks associated with wastewater-contaminated environments.

Environmental Persistence of Influenza H5N1 Is Driven by Temperature and Salinity: Insights From a Bayesian Meta-Analysis

Environmental persistence of zoonotic pathogens is a key trait that influences the probability of zoonotic spillover. Pathogen survival outside of the host determines the window available for contact with the new recipient host species and the dose of pathogen available to that host. The longer a pathogen survives in the environment, the more disconnected the reservoir and recipient hosts can be in space and time, and the more likely that an infective dose will be available to recipient hosts. Therefore, environmental persistence is a key parameter for mechanistic models needed to predict pathogen spillover. Avian influenza can be transmitted from wildlife to poultry and people in part due to its ability to persist in the environment. Considerable work has been done to quantify trends in avian influenza persistence across environmental conditions, often published in separate studies with separate datasets. In this paper, we quantify the trends and variability of avian influenza viral persistence across environmental conditions by collating disjoint experimental data on viral particle persistence in water across many studies and a range of environmental conditions. The collated data represent 120 estimates from three different studies of the decay rates of highly pathogenic avian influenza H5N1 (90 estimates from Asia and 30 from Europe) in response to temperature, pH, and salinity. We analyzed these data with a Bayesian model to control for biases with random effects and used experimental replicates and R2 estimates of the publication’s regression procedures as statistical weights. We found temperature significantly decreases persistence of H5N1 virus in water, and this effect is stronger than that of salinity alone. Salinity interacts with temperature and probably drives the most contrasting persistence scenarios between cold-saline and warm-saline water bodies, where highest and lowest persistence times could occur respectively. Our work provides needed parameters for models that examine the risk of spillover of avian influenza viruses.

Removal of bacteriophage f2 in water by Fe/Ni nanoparticles: Optimization of Fe/Ni ratio and influencing factors

Pathogenic viruses in water are seriously harmful to human health and highly resistant to conventional disinfections. As a kind of promising attempts for pollution remediation, Fe-based nanoparticles show excellent performance in removing contaminants. In this study, the Fe/Ni nanoparticles (Fe/Ni NPs) were synthesized using the self-designed device and used for bacteriophage inactivation in water. Scanning electron microscope (SEM) and X-ray diffraction (XRD) showed that the as-prepared Fe/Ni particles were spherical and the average particle size was 93 nm. The synthesized Fe/Ni NPs achieved much higher removal efficiency of bacteriophage f2 than nanoscale zero-valent iron (nZVI), while Ni nanoparticles (Ni NPs) showed no removal effect on the bacteriophage f2. The highest removal efficiency of bacteriophage f2 by Fe/Ni NPs was obtained when the primary ratio of Fe:Ni was 5:1. In addition, the removal efficiency of phage f2 under aerobic condition was significantly higher than that under anaerobic condition with Fe/Ni NPs, and the role of Ni was proved as a catalyst in the system. Besides, the effect of initial pH, initial concentration of bacteriophage f2, particles dose, rotation rate, and temperature on the removal efficiency of bacteriophage f2 were studied. The result showed that the removal efficiency of bacteriophage f2 did not change obviously in the test pH range (5–8), and was positively related with the rotation rate and negatively related with the initial concentration of bacteriophage f2. The particles dose could increase the removal efficiency of phage f2, but the removal efficiency would decrease when the dose was too much due to the aggregation of nanoparticles. The increase of temperature could increase the removal efficiency initially, but decrease the removal efficiency finally due to the accelerated corrosion of iron.

Comprehensive Study on Enteric Viruses and Indicators in Surface Water in Kyoto, Japan, During 2014-2015 Season.

Certain enteric viruses that are present in the water environment are potential risk factors of waterborne infections. To better understand the impact of viruses in water, both enteric viruses and their potential indicators should be comparatively investigated. In this study, occurrences of GI- and GII-noroviruses (NoVs), sapovirus (SaV), rotavirus (RoV), Aichi virus 1 (AiV-1), enterovirus (EV), and pepper mild mottle virus (PMMoV) were quantitatively determined in surface water samples in Japan. Additionally, the genotype distribution of GI- and GII-NoVs was determined using a next-generation amplicon sequencing. PMMoV was the most abundant virus regardless of season and location, indicating its usefulness as an indicator for the viral contamination of water. Other potential indicators, AiV and EV, were less abundant than GII-NoV. Viruses other than PMMoV showed seasonality, i.e., EV and other viruses (NoVs, SaV, RoV, and AiV-1) became prevalent during summer and winter, respectively. SaV showed a relatively high abundance at a location that was affected by untreated wastewater. Regarding NoV genotypes, GI.1, GI.2, GI.4, GI.5, GI.6, GII.3, GII.4, GII.6, and GII.17 were found from the surface water samples. GII.4 and GII.17 seemed to have contributed to the high abundance of GII-NoV in the samples. Interestingly, GII.17 strains became prevalent in the water samples before becoming prevalent among gastroenteritis patients in Japan. These findings provide further insights into the properties of viruses as contaminants in the water environment.

Synthesis and Characterization of Silver Coated Multi Walled Carbon Nanotubes for Dye Degradation in Textile Waste Water

The most important challenge across the globe in recent years is to meet the sufficient supply of drinking water and to reduce water pollution, one of the major problems is the waste water from the textile industry and the purification of dye based water is a challenge for many years. In this paper we report dye degradation in textile waste water using Ag coated MWCNTs. Multi walled carbon nanotubes were synthesized using chemical vapor deposition method, using powder catalyst and the coating of Silver in MWCNTs was done by wet chemical method. Three Different silver concentrations were taken for coating the MWCNT. These Ag coated Multiwall carbon nanotubes were characterized by X-ray Diffraction, Field Emission Scanning Electron Microscopy (FESEM) and UV spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) was used to study the morphology of the sample and Energy dispersive X-ray analysis (EDAX) characterization was done to study the chemical composition. The multiwalled carbon nanotubes act like a absorbent which helps in dye degradation and silver has antibacterial properties which help in removing the bacteria and viruses in water. The adsorption was tested for three different samples of Ag coated MWCNT’s using photocatalytic study. The UV intensity peaks showing the observable shift in intensity. Adsorption column test was done, using the Ag coated MWCNTs, using dye based water appears clear after the test.

First detection and molecular characterization of hepatitis E virus in water from wastewater treatment plants in Portugal.

First detection and molecular characterization of hepatitis E virus in water from wastewater treatment plants in Portugal.

Spatial variability in picophytoplankton, bacteria and viruses in waters of the Great Australian Bight (southern Australia)

The Great Australian Bight (GAB) is a region of great economic and ecological importance to southern Australia, supporting fisheries of national and international importance, and large populations of small pelagic fish and iconic apex predators. There is, however, limited information on the plankton forming the base of the food web and their links to higher trophic levels in the GAB. Bacteria [inclusive of Archaea], picophytoplankton (Prochlorococcus, Synechococcus and picoeukaryotes) and viruses were investigated in the central through to the eastern GAB for the first time, across five shelf edge to offshore transects in the austral Autumn of 2013. Downwelling conditions were evident over the region prior to and during the study period. Prochlorococcus numerically dominated picophytoplankton, exceeding Synechococcus and picoeukaryotes on average, by 5-fold and 30-fold respectively. Synechococcus and picoeukaryotes showed a clear shelf edge to offshore trend with highest abundances occurring at the shelf edge. Bacterial abundances showed low variation over the region, but with highest percent of high DNA bacteria (%HDNA) occurring at the shelf edge. Viral abundances closely followed bacteria, however individual viral groups were positively correlated with picophytoplankton groups, suggesting all picoplankton groups were subject to viral infection in GAB waters. Highest total picoplankton biomass occurred in surface waters at the shelf edge (26.5 ± 1.49 µg C L−1), with picophytoplankton carbon biomass (PB) and bacterial carbon biomass (BB) each accounting for ~50% of the total picoplankton biomass in the upper 60 m of the water column. Total picoplankton biomass was ~2-fold lower offshore waters, with BB comprising the bulk of the biomass (~72%). For the upper 60 m of the water column, picoeukaryotes accounted for ~51% of PB at the shelf edge, compared to ~24% in offshore waters. Based on our estimated C:Chl a ratios, picoeukaryotes accounted for 32.7 ± 3.0% of Chl a at the shelf edge, compared to 9.1 ± 0.6% in offshore waters. Prochlorococcus dominated PB in offshore waters (~67%), accounting for ~28% of Chl a. Multivariate analyses showed that the best predictors of the picoplankton community were a combination of nitrate and salinity (ρ = 0.704), indicating strong environmental forcing of the picophytoplankton community across the GAB. The elevated PB at the shelf edge, due to the dominance of picoeukaryotes, was a regional feature of the central and eastern GAB during the time of this study. We hypothesize that picoeukaryotes play a critical role in supporting higher trophic levels in GAB shelf edge waters. This study highlights the importance of small plankton in food web dynamics in GAB waters.