Levels Of Fecal Contamination Research Articles

An assessment of latrine front-end characteristics and associated surface E. coli indicated faecal contamination in rural Fiji

In Fiji, 90% of the population has access to basic sanitation; however, there are still persistent health risks from endemic faecal-oral diseases such as typhoid fever. There is a need to assess the contribution of existing sanitation facilities in the faecal pathogen transmission pathway. This study was conducted as part of a larger planetary health study across 29 rural communities within five river catchments. This specific research aimed to characterise latrine front-ends, both infrastructure and usage behaviour, and to assess the faecal contamination levels on various frequently contacted latrine surfaces in rural Fiji. A sanitation survey, along with observation and latrine swab sampling, was conducted in households over three phases: baseline (n = 311) (Aug–Dec 2019), endline (n = 262) (Jun–Sep 2022) and an in-depth front-end study (n = 12) (Oct–Nov 2022). Of 311 households, almost all had pedestal-type latrines, predominately cistern-flush (83%), followed by pour-flush (13%), and then hole-type (pit) latrines (4%). Washable latrine floors had significantly higher E. coli densities (6.7 × 102 CFU/25 cm2) compared to non-washable floors (1.3 × 102 CFU/25 cm2) (p = 0.05), despite washable floors indicating improved latrines. The in-depth front-end analysis found that moist latrine surfaces had significantly elevated E. coli densities (1.2 × 103 CFU/25 cm2) compared to the dry ones (14.3 CFU/25 cm2) (p < 0.001), highlighting the importance of maintaining dry latrine surfaces. Latrine floors and mid-walls were the most frequently contaminated surfaces, emphasising the need to clean and disinfect these surfaces. Only 46% of the households reported always using soap for handwashing after defecation, exacerbating the risk of transmitting faecal pathogens. This study highlights that latrine cleanliness and hygiene are as crucial as latrine infrastructures for the effective disruption of faecal pathogens transmission during latrine use.

Level and Origin of Faecal Contamination of the Waters of a Tropical Urban Lagoon: The Case of the Ebrié Lagoon

Level and Origin of Faecal Contamination of the Waters of a Tropical Urban Lagoon: The Case of the Ebrié Lagoon

Urban stormwater green infrastructure: Evaluating the public health service role of bioretention using microbial source tracking and bacterial community analyses

Bioretention cells (BRCs) control stormwater flow on-site during precipitation, reducing runoff and improving water quality through chemical, physical, and biological processes. While BRCs are effective in these aspects, they provide habitats for wildlife and may face microbial hazards from fecal shedding, posing a potential threat to human health and the nearby environment. However, limited knowledge exists regarding the ability to control microbial hazards (e.g., beyond using typical indicator bacteria) through stormwater biofiltration. Therefore, the purpose of this study is to characterize changes in the bacterial community of urban stormwater undergoing bioretention treatment, with the goal of assessing the public health implications of these green infrastructure solutions. Samples from BRC inflow and outflow in Columbus, Ohio, were collected post-heavy storms from October 2021 to March 2022. Conventional culture-based E. coli monitoring and microbial source tracking (MST) were conducted to identify major fecal contamination extent and its sources (i.e., human, canine, avian, and ruminant). Droplet digital polymerase chain reaction (ddPCR) was utilized to quantify the level of host-associated fecal contamination in addition to three antibiotic resistant genes (ARGs): tetracycline resistance gene (tetQ), sulfonamide resistance gene (sul1), and Klebsiella pneumoniae carbapenemase resistance gene (blaKPC). Subsequently, 16S rRNA gene sequencing was conducted to characterize bacterial community differences between stormwater BRC inflow and outflow. Untreated urban stormwater reflects anthropogenic contamination, suggesting it as a potential source of contamination to waterbodies and urban environments. When comparing inlet and outlet BRC samples, urban stormwater treated via biofiltration did not increase microbial hazards, and changes in bacterial taxa and alpha diversity were negligible. Beta diversity results reveal a significant shift in bacterial community structure, while simultaneously enhancing the water quality (i.e., reduction of metals, total suspended solids, total nitrogen) of urban stormwater. Significant correlations were found between the bacterial community diversity of urban stormwater with fecal contamination (e.g. dog) and ARG (sul1), rainfall intensity, and water quality (hardness, total phosphorous). The study concludes that bioretention technology can sustainably maintain urban microbial water quality without posing additional public health risks, making it a viable green infrastructure solution for heavy rainfall events exacerbated by climate change.

Environmental factors associated with Escherichia coli concentration at freshwater beaches on Lake Winnipeg, Manitoba, Canada

At many public beaches, routine monitoring of beach water quality using fecal indicator bacteria is conducted to evaluate the risk of recreational water illness. Results from water sample analysis can take over 24-hr, which may no longer accurately reflect current water quality conditions. This study aimed to assess which combination of environmental factors best predicts fecal contamination (E. coli) levels at two of the most popular beaches on Lake Winnipeg, Manitoba (Gimli and Grand Beach), by linking water quality data and publicly available environmental data from 2007 to 2021. We developed separate mixed effects models for each beach for two outcomes, linear (continuous log-transformed E. coli concentration) and categorical (200 CFU/100 ml threshold), to explore differences in the predictors of E. coli concentrations and exceedances of the provincial health risk threshold, respectively. We used a Directed Acyclic Graph to choose which predictor variables to include in the models. For both beaches, we identified clustering of the E. coli outcomes by year, suggesting year-specific variation. We also determined that extreme weather days, with higher levels of rainfall in the preceding 48-hr, previous day average air temperature, and previous day E. coli concentration could result in a higher probability of E. coli threshold exceedances or higher concentrations in the water bodies. In Grand Beach, we identified that days with lower average UV levels in the previous 24-hr and antecedent dry days could result in a higher probability of E. coli threshold exceedances or higher concentrations. The findings can inform possible trends in other freshwater settings and be used to help develop real-time recreational water quality predictive models to allow more accurate beach management decisions and warrant enhancement of beach monitoring programs for extreme weather events as part of the climate change preparedness efforts.

Nanopore sequencing for identification and characterization of antimicrobial-resistant Escherichia coli and Salmonella spp. from tilapia and shrimp sold at wet markets in Dhaka, Bangladesh.

Wet markets in low-and middle-income countries are often reported to have inadequate sanitation resulting in fecal contamination of sold produce. Consumption of contaminated wet market-sourced foods has been linked to individual illness and disease outbreaks. This pilot study, conducted in two major wet markets in Dhaka city, Bangladesh during a 4-month period in 2021 aimed to assess the occurrence and characteristics of Escherichia coli and non-typhoidal Salmonella spp. (NTS) from tilapia (Oreochromis niloticus) and shrimp (Penaeus monodon). Fifty-four individuals of each species were collected. The identity of the bacterial isolates was confirmed by PCR and their susceptibility toward 15 antimicrobials was tested by disk diffusion. The whole genome of 15 E. coli and nine Salmonella spp. were sequenced using Oxford Nanopore Technology. E. coli was present in 60-74% of tilapia muscle tissue and 41-44% of shrimp muscle tissue. Salmonella spp. was found in skin (29%) and gills (26%) of tilapia, and occasionally in muscle and intestinal samples of shrimp. The E. coli had several Multilocus sequence typing and serotypes and limited antimicrobial resistance (AMR) determinants, such as point mutations on glpT and pmrB. One E. coli (BD17) from tilapia carried resistance genes for beta-lactams, quinolones, and tetracycline. All the E. coli belonged to commensal phylogroups B1 and A and showed no Shiga-toxin and other virulence genes, confirming their commensal non-pathogenic status. Among the Salmonella isolates, five belonged to Kentucky serovar and had similar AMR genes and phenotypic resistance patterns. Three strains of this serovar were ST198, often associated with human disease, carried the same resistance genes, and were genetically related to strains from the region. The two undetermined sequence types of S. Kentucky were distantly related and positioned in a separate phylogenetic clade. Two Brunei serovar isolates, one Augustenborg isolate, and one Hartford isolate showed different resistance profiles. This study revealed high fecal contamination levels in tilapia and shrimp sold at two main wet markets in Dhaka. Together with the occurrence of Salmonella spp., including S. Kentucky ST198, a well-known human pathogen, these results stress the need to improve hygienic practices and sanitation standards at markets to improve food safety and protect consumer health.

Indication of Phages and Their Role in the Regulation of the Purification Process at the Govsany Aeration Station in Baku

Due to the epidemic situation and the emergence of enteroviral diseases, we set ourselves the task of conducting comprehensive virological and bacteriological studies of the wastewater, its sludge and contaminated soil from the Govsany aeration station. The fact of constant detection of enteroviruses in samples of wastewater and soil in combination with bacteriophages is considered by us as a possibility of detection of bacteriophages at WWTP sites. The 26 wastewater samples contain enteroviruses at various stages of treatment, 18 of which were characterised by high levels of faecal contamination (thermoletarian coliforms), C. perfringens and Enterococcus faecalis. In samples with high contamination (TCB up to 106 per 100 ml of wastewater), which are potentially dangerous in terms of the content of infectious disease pathogens, both bacterial and viral, the number of coliphages was below the norm. Consequently, coliphages cannot be used as a sanitary indicator of microorganisms of viral contamination. Intestinal phages are common where humans and animals live and therefore intestinal bacteria are present. Coliphages (bacteriophages) can be formed from lysogenic enterobacteria during the process of stepwise wastewater treatment at the Govsany WWTP.

Effect of some physicochemical parameters on the decay rate of enteric bacteria isolated from River Owena, Nigeria

The significance of water in public health cannot be overemphasized. In Nigeria, many people living along the courses of water bodies still source and drink from the rivers and streams. There is, therefore, the need to determine the load of contamination and effect of pH and salinity on the decay rate of enteric bacteria in water samples from River Owena, Owena, Nigeria, in order to develop adequate water quality management. Water samples from River Owena were collected from three sampling points (inflow, middle course and the outflow) along the River Owena, Nigeria. The load of enteric bacteria in the water samples was enumerated using membrane filtration technique. The physicochemical parameters of the water samples were determined using standard methods. The incidence and prevalence of gastroenteritis in the community around River Owena was determined using a structured questionnaire. Microcosm studies were used to determine the decay rate of enteric bacteria at varying salinity and pH. Canonical correlation analysis was used to describe the relationship between the load of enteric bacteria and the incidence and prevalence of gastroenteritis in the community around River Owena. The incidence and prevalence of gastroenteritis in the community around River Owena were estimated to be 0.75 and 0.51, respectively. Escherichia coli had positive relationships with incidence (r = 0.76) and prevalence (r = 0.65). Similarly, faecal coliforms had positive relationships with incidence (r = 0.82) and prevalence of gastroenteritis (r = 0.67), while enterococci showed positive relationship with incidence (r = 0.59) and prevalence of gastroenteritis (r = 0.87). Increase in pH and salinity increased the decay rate of enteric bacteria thereby reducing the growth of enteric bacteria, the optimum pH for the growth and survival of enteric bacteria ranged between pH 5.0 and pH 7.0. The optimum salinity for the growth of enteric bacteria isolated in water samples from River Owena ranged between 10 and 50% salinity. Findings revealed high levels of faecal contamination at the different representative monitoring points on River Owena, pH and salinity influenced the load and decay rate of enteric bacteria in water from River Owena.

Investigating Escherichia coli habitat transition from sediments to water in tropical urban lakes.

Escherichia coli is a commonly used faecal indicator bacterium to assess the level of faecal contamination in aquatic habitats. However, extensive studies have reported that sediment acts as a natural reservoir of E. coli in the extraintestinal environment. E. coli can be released from the sediment, and this may lead to overestimating the level of faecal contamination during water quality surveillance. Thus, we aimed to investigate the effects of E. coli habitat transition from sediment to water on its abundance in the water column. This study enumerated the abundance of E. coli in the water and sediment at five urban lakes in the Kuala Lumpur-Petaling Jaya area, state of Selangor, Malaysia. We developed a novel method for measuring habitat transition rate of sediment E. coli to the water column, and evaluated the effects of habitat transition on E. coli abundance in the water column after accounting for its decay in the water column. The abundance of E. coli in the sediment ranged from below detection to 12,000 cfu g-1, and was about one order higher than in the water column (1 to 2,300 cfu mL-1). The habitat transition rates ranged from 0.03 to 0.41 h-1. In contrast, the E. coli decay rates ranged from 0.02 to 0.16 h-1. In most cases (>80%), the habitat transition rates were higher than the decay rates in our study. Our study provided a possible explanation for the persistence of E. coli in tropical lakes. To the best of our knowledge, this is the first quantitative study on habitat transition of E. coli from sediments to water column.

Using a combination of quantitative culture, molecular, and infrastructure data to rank potential sources of fecal contamination in Town Creek Estuary, North Carolina.

Estuarine water quality is declining worldwide due to increased tourism, coastal development, and a changing climate. Although well-established methods are in place to monitor water quality, municipalities struggle to use the data to prioritize infrastructure for monitoring and repair and to determine sources of contamination when they occur. The objective of this study was to assess water quality and prioritize sources of contamination within Town Creek Estuary (TCE), Beaufort, North Carolina, by combining culture, molecular, and geographic information systems (GIS) data into a novel contamination source ranking system. Water samples were collected from TCE at ten locations on eight sampling dates in Fall 2021 (n = 80). Microbiological water quality was assessed using US Environmental Protection Agency (U.S. EPA) approved culture-based methods for fecal indicator bacteria (FIB), including analysis of total coliforms (TC), Escherichia coli (EC), and Enterococcus spp. (ENT). The quantitative microbial source tracking (qMST) human-associated fecal marker, HF183, was quantified using droplet digital PCR (ddPCR). This information was combined with environmental data and GIS information detailing proximal sewer, septic, and stormwater infrastructure to determine potential sources of fecal contamination in the estuary. Results indicated FIB concentrations were significantly and positively correlated with precipitation and increased throughout the estuary following rainfall events (p < 0.01). Sampling sites with FIB concentrations above the U.S. EPA threshold also had the highest percentages of aged, less durable piping materials. Using a novel ranking system combining concentrations of FIB, HF183, and sewer infrastructure data at each site, we found that the two sites nearest the most aged sewage infrastructure and stormwater outflows were found to have the highest levels of measurable fecal contamination. This case study supports the inclusion of both traditional water quality measurements and local infrastructure data to support the current need for municipalities to identify, prioritize, and remediate failing infrastructure.

Assessment of Physico-chemical and Bacteriological Quality of Drinking Water Sources in Kakamega County, Kenya

Water-borne diseases still present a major health burden in Africa. Large segments of the rural population here have no access to potable water. This study has been designed to assess the physico-chemical and bacteriological quality of drinking water sources in the study area. The study was conducted in Kakamega county covering the twelve sub-counties of Likuyani, Lugari, Malava, Navakholo, Lurambi, Ikolomani, Shinyalu, Mumias East, Mumias West, Matungu, Butere and Khwisero. Socio-demographic characteristics of the study populations were captured using a structured pre-tested questionnaire. The Most Probable Number (MPN) method was used to determine the abundance of Total coliforms and Escherichia coli (E. coli) in the water samples collected. Physico-chemical analyses (Temperature, pH, Electrical conductivity, Total dissolved solids and Dissolved oxygen) were carried out. Free residual chlorine was determined by colorimetric method with DPD chlorine tablets. The analyses were conducted following guidelines of American Public Health Association and WHO. Only 17% (68/400) of the study population had access to piped water in the study area. Waste management practices of the localities was found poor as more than 62 % (248/400) of the respondents dispose waste materials in open fields. All drinking water sources investigated were contaminated with Total coliforms. There was a wide variation in Total coliforms and E. coli. Total coliform counts ranged from 0.0 - 3652.5 cfu/100 ml whereas E. coli ranged from 0.0 - 33.0 cfu/100 ml. Both Rivers/streams and unprotected dug wells recorded the highest number of Total coliforms and E. coli. Piped water, Rainwater collection and Boreholes recorded the lowest number of Total coliforms and E. coli. E. coli counts in most drinking water sources investigated exceeded the maximum permissible limits set by WHO/KEBS, implying that they are not safe for household applications without prior treatment. The results indicate that protected drinking water sources (piped water, boreholes, protected dug wells and protected springs) are subjected to a high level of fecal contamination in the study area. Construction flaws on casing, concrete covers, fences, diversion ditches, and protection of springs' eyes and other plumbing accessories could be one of the causes. Protected water sources may become contaminated for other reasons, such as a lack of frequent surveillance, disinfection, and correct maintenance. Poor sanitation practices, a lack of hygiene education, poor supervision and maintenance, and inconsistent water point disinfection can all be blamed for the high levels of E. coli. The recorded temperature and pH ranged between 19.9–27.2°C and 4.8 - 9.1, respectively. Turbidity and Electric conductivity of the water samples ranged, respectively, between 0.43–467.02 NTU and 18.7–510.7 μS/cm. Residual chlorine in piped water showed a range of 0.06-1.2 ppm. In addition, Total dissolved solids were found to be between 20.1 and 639.2 mg/l; whereas Dissolved oxygen ranged from 2.2- 15.4 mg/l. The results of the current investigation showed that some bacteriological and physico-chemical parameters of the various water sources had values above the maximum permissible limits advised by WHO/KEBS. The Water sector stakeholders in the area should put in place proper intervention measures which include raising public awareness on the water quality of drinking water sources and enhancing the current infrastructure in order to reduce any potential health hazards.

Interpretation of the European legal framework for the microbiological classification of bivalve mollusc production areas

Water quality, in terms of the bacteria and viruses present, affects the incidence of microbial contamination in bivalve molluscs. The European Union Official Control Regulations manage these potential human health risks, requiring all Member States to routinely monitor the level of faecal contamination in production and relaying areas, and to classify these production areas accordingly. How a site is classified can affect business flexibility, operating costs, and even the ability to trade. The protection of public health is the primary remit of the national competent authorities implementing the regulations, while businesses are keen to achieve and maintain a classification indicative of good water quality, and to minimise the likelihood of a site being downgraded or closed. Equally, they do not want to make their customers sick. Balancing protection of public health and the viability of bivalve shellfish production is most easily achieved with a regulatory system that is responsive, adaptive and ultimately risk-based. Despite the standard legislation and supplementary guidance to ensure consistency of approach, interpretation and implementation varies across countries. Some take a risk based and more permissive approach, whilst others are much more restrictive. This indicates the ability of Member States to exert some independence within the overarching legal framework, reflecting regional variation in environmental conditions, historical approaches to shellfish hygiene controls as well as the range of relationships between producers and regulators.

Fecal Contamination in the Wastewater Irrigation System and its Health Threat to Wastewater-Based Farming Households in Addis Ababa, Ethiopia

Due to rapidly growing demand, the production of vegetables is increasing along the Akaki Rivers. The objective of this study was to examine the degree of fecal contamination and levels of fecal contamination and dissemination throughout the wastewater irrigation system. Irrigation water, irrigated soil, and leafy vegetables were collected twice during 2 vegetable growing seasons, at the maturity period of the growing season, from 19 sampling points along the 2 Akaki Rivers. Composite samples were taken from all sampling points and E.coli was enumerated. The mean E.coli load in wastewater and non-wastewater sources were 1.16±5.53 CFU/100 ml and 2.232±1.292 CFU/100 ml respectively. All counts of E. coli in the wastewater exceeded the WHO’s standards indicating that the irrigation water quality was unacceptable. In the wastewater-irrigated and non-wastewater-irrigated soil, the mean E.coli were 3.62 ±1.582 CFU/g and 1.322±87.1 CFU/g respectively. Meanwhile, the mean E.coli counts on the lettuce and Swiss chard were 78 ± 2 CFU/g and 44 ±3CFU/g respectively. The E.coli count on the leafy vegetables was found to be associated with the E.coli in the wastewater and soil. The production of leafy vegetables using wastewater with unacceptably high levels of E.coli and high occupational exposure introduces high levels of risk to the farming communities and to the consumers. Leafy, low-growing raw edible vegetables need careful treatment during food production and harvesting procedures or activities.

Physicochemical and microbial quality of drinking water in slum households of Hawassa City, Ethiopia

Drinking water quality and its public health effect are ignored in urban slum households of Ethiopia. The aim of this study was to assess physicochemical and microbial quality of drinking water stored in slum households of Hawassa City, Ethiopia. Cross-sectional study was conducted and a total of 120 water samples were collected from 60 households (60 tap, 60 households) to test the quality. Wagtech Potalab + PTW − 1000 was used to test the parameters. Physicochemical parameters—temperature, turbidity, pH and residual free chlorine were measured. Presence of total and faecal coliform bacteria was tested using the Wagtech membrane filtration procedure. Heads of the households were asked about the case of diarrhoeal diseases in any of their family members. Data were statistically analysed and compared with World Health Organization (WHO) standards. Paired t test was used to analyse the mean difference between tap and household water samples. Binary logistic regression was used to investigate any significant association between presence of faecal coliform in the water samples and occurrence of diarrhoeal diseases. Eight (13.3%) tap and 28 (46.7%) household water samples were found positive for total coliform; five (8.3%) tap and 19 (31.7%) household water samples were positive for faecal coliform. Eleven (18.3%) household water samples had faecal coliform 10–100 CFU/100 ml, which falls under high-risk category based on WHO standard. The paired t test (p < 0.05) showed significant mean difference between faecal coliform count of the tap and household water samples. The binary logistic regression analysis implied the odds for occurrence of diarrhoeal disease is 17.33 more in households with positive faecal coliform results (p < 0.05). It is concluded that there was a significant level of faecal contamination of drinking water at the household level. Therefore, it is recommended that continuous health education on drinking water handling should be given to slum households.

Assessing multiple fecal sources to surf zone waters of two recreational beaches by bacterial community analysis

Fecal sources to recreational surf zone waters should be identified to protect public health. While watershed origins of human and other fecal sources are often discoverable by quantitative polymerase chain reaction (qPCR) of fecal markers using spatially stratified samples, similarly assessing wastewater treatment plant (WWTP) outfall and other offshore contributions to surf zones is challenged by individual marker fate and transport. Here, bacterial communities were assessed for relatedness between all hypothesized fecal sources and surf zone waters for two urban California recreational beaches, by sequencing genes encoding 16S rRNA and analyzing data using SourceTracker and FEAST. Ambient marine bacterial communities dominated the surf zone, while fecal (human, dog, or gull) or wastewater (sewage or treated WWTP effluent) bacterial communities were present at low proportions and those from recycled water were absent. Based on the relative abundances of bacterial genera specifically associated with human feces, the abundances of HF183 in bacterial community sequences, and FEAST and SourceTracker results when benchmarked to HF183, the major sources of HF183 to surf zone waters were human feces and treated WWTP effluent. While surf zone sequence proportions from human sources (feces, sewage and treated WWTP effluent) appeared uncorrelated to previously obtained qPCR HF183 results, the proportions of human fecal and potential human pathogen sequences in surf zone waters were elevated when there were more swimmers (i.e. during weekday afternoons, holidays and busy weekends, and race events), thus confirming previously-published qPCR-based conclusions that bather shedding contributed low levels of human fecal contamination. Here, bacterial community sequencing also showed evidence that treated WWTP effluent from an offshore outfall was entering the surf zone, thereby resolving a prior uncertainty. Thus, bacterial community sequencing not only confirms qPCR HF183-based human marker detections, but further allows for confirming fecal sources for which individual marker quantification results can be equivocal.

Hurricane Harvey Impacts on Water Quality and Microbial Communities in Houston, TX Waterbodies.

Extreme weather events can temporarily alter the structure of coastal systems and generate floodwaters that are contaminated with fecal indicator bacteria (FIB); however, every coastal system is unique, so identification of trends and commonalities in these episodic events is challenging. To improve our understanding of the resilience of coastal systems to the disturbance of extreme weather events, we monitored water quality, FIB at three stations within Clear Lake, an estuary between Houston and Galveston, and three stations in bayous that feed into the estuary. Water samples were collected immediately before and after Hurricane Harvey (HH) and then throughout the fall of 2017. FIB levels were monitored by culturing E. coli and Enterococci. Microbial community structure was profiled by high throughput sequencing of PCR-amplified 16S rRNA gene fragments. Water quality and FIB data were also compared to historical data for these water body segments. Before HH, salinity within Clear Lake ranged from 9 to 11 practical salinity units (PSU). Immediately after the storm, salinity dropped to < 1 PSU and then gradually increased to historical levels over 2 months. Dissolved inorganic nutrient levels were also relatively low immediately after HH and returned, within a couple of months, to historical levels. FIB levels were elevated immediately after the storm; however, after 1 week, E. coli levels had decreased to what would be acceptable levels for freshwater. Enterococci levels collected several weeks after the storm were within the range of historical levels. Microbial community structure shifted from a system dominated by Cyanobacteria sp. before HH to a system dominated by Proteobacteria and Bacteroidetes immediately after. Several sequences observed only in floodwater showed similarity to sequences previously reported for samples collected following Hurricane Irene. These changes in beta diversity corresponded to salinity and nitrate/nitrite concentrations. Differential abundance analysis of metabolic pathways, predicted from 16S sequences, suggested that pathways associated with virulence and antibiotic resistance were elevated in floodwater. Overall, these results suggest that floodwater generated from these extreme events may have high levels of fecal contamination, antibiotic resistant bacteria and bacteria rarely observed in other systems.

Isolation and Identification of Bacteria found in the milt of cultured Clarias gariepinus

Bacteria identification in fish is important; hence it provides update information on emerging and existing organisms thereby enriching the gene bank on fish disease. This study investigated bacteria associated with milt in cultured samples of African catfish- Clarias gariepinus. Catfish broodstock were collected from private Fish Farm in Ogun State, Nigeria. Fish samples were taken to the Microbiology laboratory, Federal University of Agriculture, Abeokuta Ogun State for milt microbial analyses, and amplicon were taken to International Institute of Tropical Agriculture, Ibadan for molecular characterization. Bio-edit was use for importing and mining nucleotide sequences into gene bank. The results revealed that the following bacterial organisms were present in the milt of Clarias gariepinus: Aeromonas caviae, Proteus mirabilis, Serratia rubidaea, Pseudomonas mosselii, Acinetobacter soli and Klebsiella variicola. The Basic Local Alignment Search Tools revealed the percentage similarity ranging from 86- 97.04% and their accession numbers. These bacteria indicated high levels of faecal contamination in the environment. In conclusion, bacteria were found in the milt of cultured catfish and are capable of being pathogenic to humans and may increase the vertical transfer to fry during breeding and rearing stage.

Metagenomic Characterization of Microbial Pollutants and Antibiotic- and Metal-Resistance Genes in Sediments from the Canals of Venice

The spread of fecal pollutants and antibiotic resistance in the aquatic environment represents a major public health concern and is predicted to increase in light of climate change consequences and the increasing human population pressure on the lagoon and coastal areas. The city of Venice (Italy) is affected by diverse microbial pollution sources, including domestic wastewaters that, due to the lack of modern sewage treatment infrastructure in the historical city center, are released into canals. The outflowing jets of its tidal inlets thus represent a source of contamination for the nearby beaches on the barrier island separating the lagoon from the sea. Metagenomic analyses of DNA extracted from sediment samples from six sites in the canals of the city’s historic center were undertaken to characterize the microbial community composition, the presence of fecal microbes as well as other non-enteric pathogens, and the content of genes related to antibiotic (AB) and heavy metal (HM) resistance, and virulence. The six sites hosted similar prokaryotic communities, although variations in community composition likely related to oxygen availability were observed. All sites displayed relatively high levels of fecal contamination, including the presence of Fecal Indicator Bacteria, sewage- and alternative feces-associated bacteria. Relatively high levels of other potential pathogens were also found. About 1 in 500 genes identified at these sites are related to AB and HM resistance; conversely, genes related to virulence were rare. Our data suggest the existence of widespread sediment microbial pollution in the canals of Venice, coupled with the prevalence of ARGs to antibiotics frequently used in humans as well as of HMRGs to toxic metals that still persists in the lagoon. All of this evidence raises concerns about the consequences on the water quality of the lagoon and adjacent marine areas and the potential risks for humans, deserving further studies.

Improved management of farm dams increases vegetation cover, water quality, and macroinvertebrate biodiversity.

In many farming landscapes, aquatic features, such as wetlands, creeks, and dams, provide water for stock and irrigation, while also acting as habitat for a range of plants and animals. Indeed, some species threatened by land‐use change may otherwise be considerably rarer—or even suffer extinction—in the absence of these habitats. Therefore, a critical issue for the maintenance of biodiversity in agricultural landscapes is the extent to which the management of aquatic systems can promote the integration of agricultural production and biodiversity conservation. We completed a cross‐sectional study in southern New South Wales (southeastern Australia) to quantify the efficacy of two concurrently implemented management practices—partial revegetation and control of livestock grazing—aimed at enhancing the vegetation structure, biodiversity value, and water quality of farm dams. We found that excluding livestock for even short periods resulted in increased vegetation cover. Relative to unenhanced dams (such as those that remained unfenced), those that had been enhanced for several years were characterized by reduced levels of turbidity, nutrients, and fecal contamination. Enhanced dams also supported increased richness and abundance of macroinvertebrates. In contrast, unenhanced control dams tended to have high abundance of a few macroinvertebrate taxa. Notably, differences remained between the macroinvertebrate assemblages of enhanced dams and nearby “natural” waterbodies that we monitored as reference sites. While the biodiversity value of semilotic, natural waterbodies in the region cannot be replicated by artificial lentic systems, we consider the extensive system of farm dams in the region to represent a novel ecosystem that may nonetheless support some native macroinvertebrates. Our results show that management interventions such as fencing and grazing control can improve water quality in farm dams, improve vegetation structure around farm dams, and support greater abundance and diversity of aquatic macroinvertebrates.

Lab on a smartphone (LOS): A smartphone-integrated, plasmonic-enhanced optoelectrowetting (OEW) platform for on-chip water quality monitoring through LAMP assays

We present a low-cost lab-on-a-smartphone (LOS) platform for rapid and in-situ monitoring of fecal indicator bacteria (FIB) such as Escherichia coli (E. coli) to examine the presence and concentration levels of fecal contamination in environmental waters. To realize the LOS, three main components, a plasmonic-enhanced optoelectrowetting (OEW) device, a transparent heater, and a smartphone, are compactly assembled for on-chip water quality monitoring through loop-mediated isothermal amplification (LAMP) assays. The LOS integration with the OEW device enables pumpless and tubeless droplet manipulations for on-chip water sample preparation using a plasmonic-enhanced OEW technology. The integration with a transparent heater provides isothermal heating at 65 °C, where low-cost, portable LAMP assays are conveniently implemented on the LOS platform. Finally, a smartphone is used as an integrated optical detector to take digital images of target water samples during the LAMP reaction, while a time-dependent red-green-blue (RGB) analysis is performed for quantitative and accurate colorimetric study using a smartphone’s image processing app. Experimentally, we have successfully demonstrated on-chip sample processing of water samples spiked with E. coli DNA and LAMP mixtures, and conducted in-situ isothermal LAMP amplifications of E. coli DNA, while obtaining the LAMP test results within 30 min, followed by an accurate time-dependent colorimetric assessment. The LOS platform truly offers a low-cost, portable, and fully integrated system for rapid, on-site detection for the presence of FIB and their associated pathogens in environmental water without the need for sophisticated laboratory equipment or skilled personnel.

Bacteriological quality of household drinking water in North Gondar Zone, Ethiopia; a community-based cross-sectional study

Ethiopia is one of the developing countries where only 52% of its population have access to safe drinking water. To determine the level of faecal contamination in drinking water, the E. coli has been found to be the most specific indicator. The purpose of this study was to determine household bacteriological drinking water quality and its associated factors in rural North Gondar Zone Ethiopia. A community-based cross-sectional study was conducted in rural parts of North Gondar Zone from April to June, 2016. Water samples from water storage at household level were taken using standardized water sampling techniques to determine the level of faecal contamination. Face-to-face interview using structured questionnaires and checklist were used to identify the associated factors. A total of 736 households participated in this study. The prevalence of positive faecal coliform in the households is found to be 72.6% (95%C.I; 69.4–75.8). In multivariate analysis; occupational status [AOR; 0.35, 95%; CI (0.16,0.77)], income [(AOR);0.45, 95%; CI (0.3, 0.68)], type of solid waste disposal habit [AOR; 0.16, 95%; CI (0.36, 0.66)], source of water [AOR; 0.42, 95%; CI (0.28, 0.65)], shortage of water [AOR; 2.8, 95%; CI (1.88, 4)] were variables identified as predictors for faecal coliform contamination of water in the household. There is high level of faecal contamination of household drinking water in North Gondar Zone. Occupational status, income, solid waste disposal habit, sources of drinking water, and shortage of water were predictor for presence of faecal coliform contamination in household drinking water.