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As managed aquifer recharge (MAR) becomes increasingly considered for augmenting water-sensitive urban areas, fundamental knowledge of the achievable scale, longevity and maintenance requirements of different options will become paramount. This paper reports on a 39 month pilot scale MAR scheme that infiltrated secondary treated wastewater through unsaturated sand into a limestone and sand aquifer. Two types of infiltration gallery were constructed to compare their hydraulic performance, one using crushed, graded gravel, the other using an engineered leach drain system (Atlantis Leach System®). Both galleries received 25 kL of nutrient-rich, secondary treated wastewater per day. The Atlantis gallery successfully infiltrated 17 ML of treated wastewater over three years. The slotted distribution pipe in the gravel gallery became clogged with plant roots after operating for one year. The infiltration capacity of the gravel gallery could not be restored despite high pressure cleaning, thus it was replaced with an Atlantis system. Reduction in the infiltration capacity of the Atlantis system was only observed when inflow was increased by about 3 fold for two months. The performance of the Atlantis system suggests it is superior to the gravel gallery, requiring less maintenance within at least the time frame of this study. The results from a bromide tracer test revealed a minimum transport time of 3.7 days for the recharged water to reach the water table below 9 m of sand and limestone. This set a limit on the time available for attenuation by natural treatment within the unsaturated zone before it recharged groundwater. [Copyright &y& Elsevier]

Abstract: Secondary treated wastewater was infiltrated through a 9 m-thick calcareous vadose zone during a 39 month managed aquifer recharge (MAR) field trial to determine potential improvements in the recycled water quality. The water quality improvements of the recycled water were based on changes in the chemistry and microbiology of (i) the recycled water prior to infiltration relative to (ii) groundwater immediately down-gradient from the infiltration gallery. Changes in the average concentrations of several constituents in the recycled water were identified with reductions of 30% for phosphorous, 66% for fluoride, 62% for iron and 51% for total organic carbon when the secondary treated wastewater was infiltrated at an applied rate of 17.5 L per minute with a residence time of approximately four days in the vadose zone and less than two days in the aquifer. Reductions were also noted for oxazepam and temazepam among the pharmaceuticals tested and for a range of microbial pathogens, but reductions were harder to quantify as their magnitudes varied over time. Total nitrogen and carbamazepine persisted in groundwater down-gradient from the infiltration galleries. Infiltration does potentially offer a range of water quality improvements over direct injection to the water table without passage through the unsaturated zone; however, additional treatment options for the non-potable water may still need to be considered, depending on the receiving environment or the end use of the recovered water. [Copyright &y& Elsevier]

Abstract: A bioanalytical test battery was used for monitoring organic micropollutants across an indirect potable reuse scheme testing sites across the complete water cycle from sewage to drinking water to assess the efficacy of different treatment barriers. The indirect potable reuse scheme consists of seven treatment barriers: (1) source control, (2) wastewater treatment plant, (3) microfiltration, (4) reverse osmosis, (5) advanced oxidation, (6) natural environment in a reservoir and (7) drinking water treatment plant. Bioanalytical results provide complementary information to chemical analysis on the sum of micropollutants acting together in mixtures. Six endpoints targeting the groups of chemicals with modes of toxic action of particular relevance for human and environmental health were included in the evaluation: genotoxicity, estrogenicity (endocrine disruption), neurotoxicity, phytotoxicity, dioxin-like activity and non-specific cell toxicity. The toxicity of water samples was expressed as toxic equivalent concentrations (TEQ), a measure that translates the effect of the mixtures of unknown and potentially unidentified chemicals in a water sample to the effect that a known reference compound would cause. For each bioassay a different representative reference compound was selected. In this study, the TEQ concept was applied for the first time to the umuC test indicative of genotoxicity using 4-nitroquinoline as the reference compound for direct genotoxicity and benzo[a]pyrene for genotoxicity after metabolic activation. The TEQ were observed to decrease across the seven treatment barriers in all six selected bioassays. Each bioassay showed a differentiated picture representative for a different group of chemicals and their mixture effect. The TEQ of the samples across the seven barriers were in the same order of magnitude as seen during previous individual studies in wastewater and advanced water treatment plants and reservoirs. For the first time a benchmarking was performed that allows direct comparison of different treatment technologies and covers several orders of magnitude of TEQ from highly contaminated sewage to drinking water with TEQ close or below the limit of detection. Detection limits of the bioassays were decreased in comparison to earlier studies by optimizing sample preparation and test protocols, and were comparable to or lower than the quantification limits of the routine chemical analysis, which allowed monitoring of the presence and removal of micropollutants post Barrier 2 and in drinking water. The results obtained by bioanalytical tools were reproducible, robust and consistent with previous studies assessing the effectiveness of the wastewater and advanced water treatment plants. The results of this study indicate that bioanalytical results expressed as TEQ are useful to assess removal efficiency of micropollutants throughout all treatment steps of water recycling. [Copyright &y& Elsevier]

Abstract: Managed Aquifer Recharge (MAR) is becoming a mechanism used for recycling treated wastewater and captured urban stormwater and is being used as a treatment barrier to remove contaminants such as pathogens from the recharged water. There is still a need, however, to demonstrate the effectiveness of MAR to reduce any residual risk of pathogens in the recovered water. A MAR research site recharging secondary treated wastewater in an unconfined carbonate aquifer was used in conjunction with a static Quantitative Microbial Risk Assessment (QMRA) to assess the microbial pathogen risk in the recovered water following infiltration and aquifer passage. The research involved undertaking a detailed hydrogeological assessment of the aquifer at the MAR site and determining the decay rates of reference pathogens from an in-situ decay study. These variables along with literature data were then used in the static QMRA which demonstrated that the recovered water at this site did not meet the Australian Guidelines for recycled water when used for differing private green space irrigation scenarios. The results also confirmed the importance of obtaining local hydrogeological data as local heterogeneity can influence of residence time in the aquifer which, in turn, influences the outcomes. The research demonstrated that a static QMRA can be used to determine the residual risk from pathogens in recovered water and showed that it can be a valuable tool in the preliminary design and operation of MAR systems and the incorporation of complementary engineered treatment processes to ensure that there is acceptable health risk from the recovered water. [Copyright &y& Elsevier]

A growing beneficial reuse of biosolids in agriculture has led to concerns about potential contamination of water resources and the food chain. In order to comprehend the potential risks of transmission of diseases to the human population, an advanced quantitative risk assessment is essential. This requires good quantitative data which is currently limited due to the methodological limitations. Consequently, further development and standardization of methodologies for the detection, enumeration and viability assessment of pathogens in biosolids is required. There is a paucity of information on the numbers and survival of enteric virus and protozoan pathogens of concern in biosolids. There is a growing urgency for the identification of more reliable alternative indicators, both index and model microorganisms, which could be used for potential public health risk assessment. In this review, we have summarized reported literature on the numbers and fate of enteric pathogens and indicators in biosolids. The advantages and limitations of the use of conventional and alternative index and model microorganisms for the prediction of pathogen presence in biosolids are also discussed. [Copyright &y& Elsevier]

Biodegradation and adsorption of selected endocrine-disrupting chemicals (EDCs), namely estrogens (E2 and EE2) and phenolic compounds (BPA, 4-t-OP and 4-n-NP), in aquifer materials was investigated in the laboratory in order to understand the behaviour and fate of these chemicals associated with reclaimed water during managed aquifer recharge. Biodegradation experiments were conducted in microcosms with aquifer material and groundwater mixture, or with aquifer material and effluent mixture in the presence of glucose under both aerobic and anoxic conditions. All five selected compounds were degraded by microorganisms in both types of aquifer material–water mixtures under aerobic and anoxic conditions. Under aerobic conditions, EE2 was found to degrade faster in the aquifer material supplemented with effluent with a half-life of 15 days compared with that of 26 days in the aquifer material and groundwater microcosm. No significant difference between the two aquifer material–water mixtures was found for the other four compounds with half-lives ranging between 0.2 and 4.1 days. Under anoxic conditions, however, little biodegradation was observed for the selected EDCs except for E2, which degraded in the aquifer material in the presence of both water types. [Copyright &y& Elsevier]

Abstract: There is an increasing trend to require more efficient use of water resources, both in urban and rural environments. A major mechanism that can be used to achieve greater efficiencies is the reuse of water that once would have been discarded into the environment after use. The reuse of water for agricultural irrigation is often viewed as a positive means of recycling water due to the potential large volumes of water that can be used. Recycled water can have the advantage of being a constant, reliable water source and reduces the amount of water extracted from the environment. In addition, in some cases treatment requirements may be need to be less than for water used in an urban environment due to less potential human contact. There are concerns and unknowns, however, about the impact of the quality of the recycled water, both on the crop itself and on the end users of the crops. Water quality issues that can create real or perceived problems in agriculture include nutrient and sodium concentrations, heavy metals, and the presence of contaminants such as human and animal pathogens, pharmaceuticals and endocrine disruptors. Social attitudes to the use of crops that have been irrigated with recycled waters and the resulting impact on market value of crops are also a major consideration. This paper will discuss the benefits from using different types of recycled water and outline the current knowledge and opinions relating to risks such as water quality issues. [Copyright &y& Elsevier]

This study was based on the hypothesis that groundwater-derived biofilms may provide a reservoir for coliform or pathogenic bacteria as has been observed in drinking water distribution systems. Escherichia coli, labelled with green fluorescent protein, was found to colonize all layers of mixed-population biofilms developed in association with indigenous groundwater micro-organisms in a laboratory-scale reactor. Biofilm-associated E. coli was removed at a slower rate from the reactor flasks than planktonic E. coil under a continuous flow regime. During flow-through of groundwater, planktonic E. coli removal was slower in flasks containing coverslips for enhanced biofilm development compared to a control flask without coverslips. Conversely, during flow-through of treated effluent, planktonic E. coli removal was faster in flasks with coverslips compared to without. Removal of attached E. coli was also fastest in the coverslip-containing flasks with effluent flowthrough. This suggests that an increase in available nutrients may reduce E. coli survival potential due to either enhanced competition for nutrients or enhanced antagonism by the indigenous microbial population. Under identical conditions, GFP-labelled Pseudomonas aeruginosa was found to persist in the biofilms for longer than E. coli, most notably when exposed to flow-through of treated effluent. However, prolonged persistence of P. aeruginosa in the effluent could not be attributed to an association with the biofilms. This study has shown that under certain conditions the presence of mixed-population biofilms may limit the survival potential of enteric bacterial pathogens introduced into groundwater. [ABSTRACT FROM AUTHOR]

Enteric pathogens can be present in drinking water catchments due to several point and non-point sources of faecal contamination. Pathogen and contaminant signatures will decay due to environmental stresses, such as temperature, Ultra Violet (UV) radiation, salinity, and predation. In this study, we determined the decay of the culturable faecal indicator bacterium (FIB) Escherichia coli (E. coli), two sewage-associated marker genes (Bacteroides HF183 and crAssphage CPQ_056), and enteric pathogens (Campylobacter spp., human adenovirus 40/41, and Cryptosporidium parvum) in two freshwater laboratory microcosms using culture-based, quantitative PCR (qPCR) and vital dye (determine the fraction of viable Cryptosporidium oocysts) assays. Freshwater samples from the Lake Wappa and Lake Wivenhoe (Australia) were seeded with untreated sewage and C. parvum oocysts, and their declining concentrations were measured over a 28-day period. Moreover, 16S rRNA amplicon sequencing was also undertaken to determine the change/shift in sewage-associated bacterial communities using SourceTracker. Overall, culturable E. coli and the HF183 marker gene decayed significantly (p < 0.05) faster than did the qPCR measured enteric pathogens suggesting that the absence of culturable FIB or qPCR HF183 in water samples may not indicate the absence of pathogens. The decay of crAssphage was similar to that of HAdV 40/41 and other pathogens tested, suggesting crAssphage may be a better surrogate for enteric viruses in sub-tropical catchment waters. The decay rates were greater at 25 °C compared to 15 °C, suggesting that FIB and pathogens persist longer in the winter season compared to summer. Overall decay rates of the tested microorganisms in this microcosm study suggest that sub-tropical conditions, especially temperature, have a negative impact on the persistence of tested microorganisms. Sewage-associated bacterial communities also showed similar patterns. Based on the results, which showed differences in simulated summer and winter temperatures for pathogen decay, corresponding management options and treatment need to be adjusted accordingly to minimize human health risks effectively. Unlabelled Image • The HF183 marker gene decayed significantly (p < 0.05) faster than pathogens. • The decay of crAssphage was similar to that of HAdV 40/41. • The decay rates of tested organisms were greater at 25 °C compared to 15 °C. • The persistence of microorganisms is affected by temperature. [ABSTRACT FROM AUTHOR]

Introduction: Household food insecurity and inadequate water, sanitation, and hygiene (WASH) contribute to ill health. However, the interactions between household food insecurity, WASH and health have been rarely assessed concurrently. This study investigated compounded impacts of household food insecurity and WASH on self-reported physical and mental health of adults in the Vietnamese Mekong Delta. Materials and methods: This cross-sectional survey interviewed 552 households in one northern and one southern province of the Vietnamese Mekong Delta. The survey incorporated previously validated tools such as the Short Form 12-item Health Survey, Household Food Insecurity Assessment Scale, and the Access and Behavioural Outcome Indicators for Water, Sanitation, and Hygiene. Physical and mental health were quantified using the physical health composite score (PCS) and mental health composite score (MCS), respectively. These measures were the dependent variables of interest for this study. Results: Statistical analysis revealed that household food insecurity and using <50 litres of water per person per day (pppd) were independently associated with lower PCS (p<0.05), after adjusting for socio-economic confounders. Household food insecurity and lack of food availability, using <50 litres of water pppd, and the use of untreated drinking water were associated with lower MCS (p<0.05), with water usage being an effect modifier of the relationship between household food insecurity and MCS. The results indicate that being food insecure and having limited potable quality water had a compounding effect on MCS, compared to being individually either food insecure or having limited water. Conclusion: This study is one of only a few that have established a link between potable water availability, food insecurity and poorer physical and mental health. The results also indicate a need to validate national data with fine-scale investigations in less populous regions to evaluate national initiatives with local populations that may be at higher risk. Adopting joint dual-action policies for interventions that simultaneously address water and food insecurity should result in larger improvements in health, particularly mental health, compared to targeting either food or water insecurity in isolation. [ABSTRACT FROM AUTHOR]

Demands on global water supplies are increasing in response to the need to provide more food, water, and energy for a rapidly growing population. These water stressors are exacerbated by climate change, as well as the growth and urbanisation of industry and commerce. Consequently, urban water authorities around the globe are exploring alternative water sources to meet ever-increasing demands. These alternative sources are primarily treated sewage, stormwater, and groundwater. Stormwater including roof-harvested rainwater has been considered as an alternative water source for both potable and non-potable uses. One of the most significant issues concerning alternative water reuse is the public health risk associated with chemical and microbial contaminants. Several studies to date have quantified fecal indicators and pathogens in stormwater. Microbial source tracking (MST) approaches have also been used to determine the sources of fecal contamination in stormwater and receiving waters. This review paper summarizes occurrence and concentrations of fecal indicators, pathogens, and MST marker genes in urban stormwater. A section of the review highlights the removal of fecal indicators and pathogens through water sensitive urban design (WSUD) or Best Management Practices (BMPs). We also discuss approaches for assessing and mitigating health risks associated with stormwater, including a summary of existing quantitative microbial risk assessment (QMRA) models for potable and non-potable reuse of stormwater. Finally, the most critical research gaps are identified for formulating risk management strategies. Unlabelled Image • Stormwater has been considered as an alternative water source. • Microbial contamination hinders stormwater reuse. • WSUD is effective in removing pathogens but requires more validation. • QMRA analysis can facilitate decision making and risk management efforts. [ABSTRACT FROM AUTHOR]

A quantitative microbial risk assessment (QMRA) of opportunistic pathogens Legionella pneumophila (LP) and Mycobacterium avium complex (MAC) was undertaken for various uses of roof-harvested rainwater (RHRW) reported in Queensland, Australia to identify appropriate usages and guide risk management practices. Risks from inhalation of aerosols due to showering, swimming in pools topped up with RHRW, use of a garden hose, car washing, and toilet flushing with RHRW were considered for LP while both ingestion (drinking, produce consumption, and accidental ingestion from various activities) and inhalation risks were considered for MAC. The drinking water route of exposure presented the greatest risks due to cervical lymphadenitis and disseminated infection health endpoints for children and immune-compromised populations, respectively. It is therefore not recommended that these populations consume untreated rainwater. LP risks were up to 6 orders of magnitude higher than MAC risks for the inhalation route of exposure for all scenarios. Both inhalation and ingestion QMRA simulations support that while drinking, showering, and garden hosing with RHRW may present the highest risks, car washing and clothes washing could constitute appropriate uses of RHRW for all populations, and toilet flushing and consumption of lettuce irrigation with RHRW would be appropriate for non- immune-compromised populations. [ABSTRACT FROM AUTHOR]

Treated effluent is increasingly being used to irrigate municipal green spaces such as sporting ovals, but the potential risks to human health from faecal-oral pathogens present in the effluent have remained largely unreported. This is the first reported study where a quantitative microbial risk assessment (QMRA) was performed to evaluate the effect of varying withholding periods in terms of pathogen inactivation credits to risks to human health from sporting ovals irrigated with secondary treated effluent. The calculations on pathogen removal rates in this study suggest that a mean 0.7 log removal for bacteria and 0.4 log for viral pathogens could be achieved over a 4 hour period. [ABSTRACT FROM AUTHOR]

A quantitative microbial risk assessment (QMRA) was undertaken to determine the potential human health risks associated with use of untreated groundwater from a superficial aquifer in a new residential urban development.In situpathogen survival experiments determined the attenuation rates of selected pathogens.Cryptosporidiumoocysts,Giardiacysts,E. coli,Campylobacter jejuni,and MS2 bacteriophage had 1 log10(90%) reduction times (T90) ranging from 2 to 42 days. Adenovirus displayed distinctly non-linear broken stick decay rates with an initial T90of 5 days to day 14, after which the T90declined to ∼100 days. The QMRA suggested that aquifer attachment was the dominant form of pathogen removal followed by natural attenuation. The QMRA results showed that under the exposure scenarios tested the mean human health risks were all acceptable with calculated Disability Adjusted Life Years (DALYs < 1 × 10− 6/person/year). [ABSTRACT FROM AUTHOR]

Abstract: An accurate quantitative detection of enteric viruses from the primary wastewater requires, sample concentration followed by extraction of nucleic acid with high purity. A highly efficient and sensitive method was developed for the concentration and quantitative detection of human adenovirus (HAdv) from wastewater samples. The two-step method which combines concentration of virus from 10mL sample with centrifugal filters followed by extraction and purification of DNA with commercially available nucleic acid extraction kit resulted in high purity DNA for downstream quantitative PCR (qPCR). The results obtained on analytical sensitivities of five commercial nucleic acid extraction kits show that they differ in their ability for DNA yield and purity. Nevertheless, despite variable analytical sensitivities extracted nucleic acid was found to be relatively PCR inhibition free. The genomic copy numbers of HAdv detected from the same concentrated wastewater sample were significantly higher (P <0.01) when Qiagen Blood and Tissue kit (1.54×106 L−1) was used as compared to Mo-Bio PowerSoil kit (5.30×105 L−1) which suggests that the nucleic acid extraction kit can influence the sensitivity of qPCR assays. The method developed in this study is simple, rapid, sensitive, and can be applicable for the qPCR detection of adenovirus and other DNA virus in wastewater. [Copyright &y& Elsevier]

Abstract: A quantitative microbial risk assessment (QMRA) was performed at four managed aquifer recharge (MAR) sites (Australia, South Africa, Belgium, Mexico) where reclaimed wastewater and stormwater is recycled via aquifers for drinking water supplies, using the same risk-based approach that is used for public water supplies. For each of the sites, the aquifer treatment barrier was assessed for its log10 removal capacity much like for other water treatment technologies. This information was then integrated into a broader risk assessment to determine the human health burden from the four MAR sites. For the Australian and South African cases, managing the aquifer treatment barrier was found to be critical for the schemes to have low risk. For the Belgian case study, the large treatment trains both in terms of pre- and post-aquifer recharge ensures that the risk is always low. In the Mexico case study, the risk was high due to the lack of pre-treatment and the low residence times of the recharge water in the aquifer. A further sensitivity analysis demonstrated that human health risk can be managed if aquifers are integrated into a treatment train to attenuate pathogens. However, reduction in human health disease burden (as measured in disability adjusted life years, DALYs) varied depending upon the number of pathogens in the recharge source water. The beta-Poisson dose response curve used for translating rotavirus and Cryptosporidium numbers into DALYs coupled with their slow environmental decay rates means poor quality injectant leads to aquifers having reduced value to reduce DALYs. For these systems, like the Mexican case study, longer residence times are required to meet their DALYs guideline for drinking water. Nevertheless the results showed that the risks from pathogens can still be reduced and recharging via an aquifer is safer than discharging directly into surface water bodies. [Copyright &y& Elsevier]

Abstract: Two case studies are described that explain the role, value, limitations and policy requirements for storing reclaimed water in aquifers for indirect reuse. The first case involves aquifer storage and recovery of water, the product of tertiary treated municipal sewage effluent, via a single injection and recovery well at Bolivar, South Australia. The recovered water, like the source water for injection, is used for unrestricted irrigation of horticulture. A limestone aquifer at a depth of 100 to 160 m confined by clay and containing brackish groundwater provides the storage zone. In the second case, located at Alice Springs, trials are proceeding to assist in the design and establishment of a soil–aquifer treatment system which will allow water derived from secondary treatment of municipal sewage effluent to be stored in an unconfined alluvial aquifer for irrigation of horticulture. Intermittent infiltration from basins provides supplementary water treatment. In each case, the motivations, choice of methods, required investigations, public consultation processes, and economics of subsurface storage are presented. The lessons learned that may assist with development of policies to facilitate environmentally sustainable subsurface storage of water in water reuse projects are discussed. [Copyright &y& Elsevier]

A quantitative PCR (qPCR) assay was used to quantify Ancylostoma caninum ova in wastewater and sludge samples. 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 samples. The newly developed qPCR assay estimated an average of 3.7 × 10 3 gene copies per ovum, which was then validated by seeding known numbers of hookworm ova into treated wastewater. The qPCR estimated an average of (1.1 ± 0.1), (8.6 ± 2.9) and (67.3 ± 10.4) ova for treated wastewater that was seeded with (1 ± 0), (10 ± 2) and (100 ± 21) ova, respectively. The further application of the qPCR assay for the quantification of A. caninum ova was determined by seeding a known numbers of ova into the wastewater matrices. The qPCR results indicated that 50%, 90% and 67% of treated wastewater (1 L), raw wastewater (1 L) and sludge (~ 4 g) samples had variable numbers of A. caninum gene copies. After conversion of the qPCR estimated gene copy numbers to ova for treated wastewater, raw wastewater, and sludge samples, had an average of 0.02, 1.24 and 67 ova, respectively. The result of this study indicated that qPCR can be used for the quantification of hookworm ova from wastewater and sludge samples; however, caution is advised in interpreting qPCR generated data for health risk assessment. [ABSTRACT FROM AUTHOR]

In this study, we investigated the use of Illumina high-throughput sequencing of 16S ribosomal RNA (rRNA) amplicons to explore microbial diversity and community structure in raw and secondary treated wastewater (WW) samples from four municipal wastewater treatment plants (WWTPs A-D) across Australia. Sequence reads were analyzed to determine the abundance and diversity of bacterial communities in raw and secondary treated WW samples across the four WWTPs. In addition, sequence reads were also characterized to phenotypic features and to estimate the abundance of potential pathogenic bacterial genera and antibiotic-resistant genes in total bacterial communities. The mean coverage, Shannon diversity index, observed richness ( S ), and abundance-based coverage estimate (ACE) of richness for raw and secondary treated WW samples did not differ significantly ( P > 0.05) among the four WWTPs examined. Generally, raw and secondary treated WW samples were dominated by members of the genera Pseudomonas, Arcobacter, and Bacteroides. Evaluation of source contributions to secondary treated WW, done using SourceTracker, revealed that 8.80-61.4% of the bacterial communities in secondary treated WW samples were attributed to raw WW. Twenty-five bacterial genera were classified as containing potential bacterial pathogens. The abundance of potentially pathogenic genera in raw WW samples was higher than that found in secondary treated WW samples. Among the pathogenic genera identified, Pseudomonas and Arcobacter had the greatest percentage of the sequence reads. The abundances of antibiotic resistance genes were generally low (<0.5%), except for genes encoding ABC transporters, which accounted for approximately 3% of inferred genes. These findings provided a comprehensive profile of bacterial communities, including potential bacterial pathogens and antibiotic-resistant genes, in raw and secondary treated WW samples from four WWTPs across Australia and demonstrated that Illumina high-throughput sequencing can be an alternative approach for monitoring WW quality in order to protect environmental and human health. [ABSTRACT FROM AUTHOR]

Escherichia coli isolates (n = 300) collected from six sites in subtropical Brisbane, Australia, prior to and after storm events were tested for the presence of 11 virulence genes (VGs) specific to diarrheagenic pathotypes. The presence of eaeA, stx1, stx2, and ehxA genes specific for the enterohemorrhagic E. coli (EHEC) pathotype was detected in 56%, 6%, 10%, and 13% of isolates, respectively. The VGs astA (69%) and aggR (29%), carried by enteroaggregative (EAEC) pathotypes, were frequently detected in E. coli isolates. The enteropathogenic E. coli (EPEC) gene bfp was detected in 24% of isolates. In addition, enteroinvasive E. coli (EIEC) VG ipaH was also detected in 14% of isolates. During dry periods, isolates belonging to the EAEC pathotype were most commonly detected (23%), followed byEHEC (11%) and EPEC (11%). Conversely, a more uniform prevalence of pathotypes, EPEC (14%), EAEC (12%), EIEC (10%), EHEC (7%), and ETEC (7%), was observed after the storm events. The results of this study highlight the widespread occurrence of potentially diarrheagenic pathotypes in the urban aquatic ecosystems. While the presence of VGs in E. coli isolates alone is insufficient to determine pathogenicity, the presence of diarrheagenic E. coli pathotypes in high frequency after the storm events could lead to increased health risks if untreated storm water were to be used for nonpotable purposes and recreational activities. [ABSTRACT FROM AUTHOR]

Abstract: Salmonella is one of the leading causes of intestinal illness all over the world as well as the etiological agent of more severe systemic diseases such as typhoid and paratyphoid fevers. While water is known to be a common vehicle for the transmission of typhoidal Salmonella serovars, non-typhoidal salmonellae are mainly known as foodborne pathogens. This paper provides a brief review of the last ten years of peer reviewed publications on the prevalence of Salmonella in natural freshwaters and drinking waters, and on the relevance of these sources for Salmonella dissemination. In industrialized countries, Salmonella was rarely reported in water-borne outbreaks despite it being frequently detected in surface waters including recreational waters and waters used for irrigation or as a drinking water source. Consistent contamination with irrigation waters has been shown to be a common route of crop contamination in produces related Salmonella outbreaks. Multiple drug resistant (MDR) Salmonella strains, that represent an increased hazard for human health and that may contribute to the dissemination of drug resistances were also detected in surface water in developed countries. Surface runoff was shown to play a main role as driver of Salmonella load in surface waters. Accordingly, analysis of serovars indicated a mixed human and animal origin of Salmonella contribution to surface waters, emphasizing the role of wild life animals in water contamination. Data relating to Salmonella prevalence in surface and drinking water in developing countries are quite rare. Nevertheless, data on water-borne outbreaks as well as case control studies investigating the risk factors for endemic typhoid fever confirmed the relevance of water as source for the transmission of this disease. In addition epidemiological studies and Salmonella surveys, consistently provided an undeniable evidence of the relevance of MDR Salmonella Typhi strains in water-borne typhoid fever in developing countries. [Copyright &y& Elsevier]

The morphology of five unicellular cyanobacterial species from two genera was compared using transmission electron microscopy (TEM) and statistical analyses. Cyanobacteria symbiotic with marine sponges from Australia and the Mediterranean were investigated, together with cyanobacteria from the water column in Western Australia. The aim was to establish whether phenotypic characteristics are useful for distinguishing cyanobacterial species, and to investigate the possible relationships of host species and geographic location on cyanobacterial morphology. Analysis of variance (ANOVA) demonstrated that cell size of the symbionts, Synechococcus spongiarum and Aphanocapsa feldmannii , is directly correlated with the number of turns of the thylakoid, and this must be accounted for in comparative morphological analyses. S. spongiarum cells were approximately one third smaller than those of A . feldmannii , but did not vary significantly in size in Chondrilla australiensis collected from different localities, or in different hosts, including C. nucula and Ircinia variabilis . Other symbionts, including Oscillatoria sp. from Cymbastela marshae , and Aphanocapsa raspaigellae from I. variabilis , were readily distinguished in the sponges examined, both by size and ultrastructural features. While morphological differences appear to be useful in differentiating A. feldmannii from S . spongiarum , morphological similarities are not a reliable indication that coccoid cyanobacteria are the same species. [ABSTRACT FROM AUTHOR]