Although sources of faecal pathogens abound in urban environments, faecal bacteria on city streets remain largely unquantified. The extent to which faecal pathogens transfer between outdoor and ...indoor environments is also poorly understood. We use defined substrate analysis to quantify enterococci and coliform faecal indicator bacteria (FIB) on interior floor surfaces in a New York City institutional building, on shoe soles of building occupants and on exterior sidewalks. Enterococci and faecal coliforms are ubiquitous on interior floors, varying with foot traffic and floor surface type. Mean enterococci counts are highest in the heavily trafficked building entryway compared with less trafficked interior locations, and counts are significantly higher on carpets than on adjacent uncarpeted flooring. Enterococci and faecal coliforms appear on shoe soles of building occupants as well. Susceptibility of shoe sole bacteria to antimicrobial agents is commensurate with that of cultivated E. coli, E. faecalis and S. aureus strains. In pooled rainwater on city sidewalks, enterococci average 31,000 per 100 mL. Overall, our evidence indicates ubiquity of FIB on sidewalks, a translocation pathway via shoe soles and accumulation on indoor floor surfaces, particularly carpeted areas. These findings present ample opportunity for human exposure to faecal pathogens in the indoor environment.
Aims
Beach water quality is regulated by faecal indicator bacteria levels, sand is not, despite known human health risk from exposure to beach sand. We compared the performance of three methods to ...extract bacterial DNA from beach sand as a step toward a standard method.
Methods and results
The analytical sensitivity of quantitative polymerase chain reaction (qPCR) for Enterococcus was compared for the slurry (suspension, agitation, membrane filtration of supernatant), versus direct extraction using PowerSoil™ or PowerMax Soil™ kits. The slurry method had the lowest limit of detection at 20–80 gene copies g−1, recovered significantly more DNA, and the only method that detected Enterococcus by qPCR in all samples; therefore, the only method used in subsequent experiments. The slurry method reflected the spatial variability of Enterococcus in individual transect samples. Mean recovery efficiency of the microbial source tracking marker HF183 from wastewater spiked marine and freshwater beach sand was 100.8% and 64.1%, respectively, but varied, indicating that the mixing protocol needs improvement.
Conclusions
Among the three methods, the slurry method had the best analytical sensitivity and produced extracts that were useful for culture or molecular analysis.
Significance and impact of study
Standardization of methods for extraction of bacterial DNA from sand facilitates comparisons among studies, and ultimately contributes to the safety of recreational beaches.
Aims
To determine inactivation of Cryptosporidium parvum oocysts and reduction of Escherichia coli and enterococci in cattle slurry added aqueous ammonia.
Methods and Results
Escherichia coli, ...enterococci and nonviable C. parvum oocysts (DAPI+PI+) were enumerated every second day for 2 weeks in cattle slurry amended with 60 mmol l−1 aq. ammonia and compared with untreated slurry at three temperatures. Regardless of temperature, the proportion of nonviable C. parvum oocysts increased significantly faster over time in slurry with added ammonia than raw slurry (P = 0·021) corresponding to 62·0% higher inactivation (P = 0·001) at day 14. Additionally, 91·8% fewer E. coli and 27·3% fewer enterococci were observed in slurry added ammonia at day 14 compared to raw slurry.
Conclusion
The addition of aqueous ammonia to raw slurry significantly reduced the viability of C. parvum oocysts and numbers of bacterial indicators. Hence, ammonia is usable at lower pathogen concentrations in slurry before application to agricultural land.
Significance and Impact of the Study
Livestock waste is a valuable source of plant nutrients and organic matter, but may contain high concentrations of pathogens like E. coli and Cryptosporidium sp. that can be spread in the environment, and cause disease outbreaks. However, die‐off rates of pathogens in organic waste can increase following increasing ammonia concentrations.
The occurrence of pathogens in discharged wastewater effluent may constitute potential public health risks. This study assessed the physicochemical and bacteriological characteristics of water ...samples taken from the Wupa River in Abuja, Nigeria, which receives the final effluent of the Wupa Wastewater Treatment Plant. Sixty sewage/water samples were collected over 12 months from five sampling points. Coliform bacteria and
Escherichia coli
were simultaneously enumerated using the membrane filtration technique and Chromocult Coliform Agar. HANNA multiparameter metre was used to measure the physicochemical parameters including temperature, pH, electrical conductivity (EC), dissolved oxygen (DO) and total dissolved solids (TDS). Results of the bacteriological analysis showed that impermissible high mean counts of
E. coli
(≥ 1.2 × 10
4
CFU/100 ml) and total coliforms (≥ 5.4 × 10
4
CFU/100 ml) were detected in 95% and 100% of the water samples respectively. These values exceed the acceptable standard limits. The mean values of physicochemical parameters ranged from 6.3 to 8.7, 20.9 to 27.3 °C, 116 to 325.0 µS/cm, 1.3 to 11.4 mg/l and 98.0 to 180.0 mg/l for pH, temperature, EC, DO and TDS respectively, with all conforming to international and national standards. Wupa River seems to have a minor negative environmental impact, per the physicochemical data obtained in this study. However, the high counts of faecal indicator bacteria demonstrated in the effluent samples were higher than those of the river at both upstream and downstream sites, implying that the river microbial load may increase to constitute an unchecked environmental hazard. Adequate disinfection of the Wupa plant effluent before discharge into the Wupa River is imperative.
The survival of
(
) bacteria, the most common faecal indicator bacteria (FIB), may be significantly affected by cyanobacteria present during a harmful algal bloom (HAB). Therefore, the effect of
on ...the survival of FIB
and coliforms was investigated. Microcosms containing two species of
(
and
) were established and then inoculated with four reference strains of
(ATCC 25922, 8739, 51813, and 11775) to explore the cyanobacteria-bacteria dynamics at a laboratory setting. Monitoring over several days showed normal growth of
, with or without the presence of
. However,
was shown to dramatically decrease the survival of
over time. Analysis of microcystin production by
was found to correlate with loss of
, suggesting a toxic effect of microcystins on
bacteria. This phenomenon was also demonstrated for a natural consortium of
and coliform bacteria by inoculating with contaminated lake water. The results indicate that the use of
as FIB may be greatly compromised in the presence of
spp. such as during a HAB when associated toxins are produced.
The revised Bathing Water Directive (2006/7/EC) requires EU member states to minimise the risk to public health from faecal pollution at bathing waters through improved monitoring and management ...approaches. While increasingly sophisticated measurement methods (such as microbial source tracking) assist in the management of bathing water resources, the use of deterministic predictive models for this purpose, while having the potential to provide decision making support, remains less common.
This study explores an integrated, deterministic catchment-coastal hydro-environmental model as a decision-making tool for beach management which, based on advance predictions of bathing water quality, can inform beach managers on appropriate management actions (to prohibit bathing or advise the public not to bathe) in the event of a poor water quality forecast. The model provides a ‘moving window’ five-day forecast of Escherichia coli levels at a bathing water compliance point off the Irish coast and the accuracy of bathing water management decisions were investigated for model predictions under two scenarios over the period from the 11th August to the 5th September, 2012. Decisions for Scenario 1 were based on model predictions where rainfall forecasts from a meteorological source (www.yr.no) were used to drive the rainfall–runoff processes in the catchment component of the model, and for Scenario 2, were based on predictions that were improved by incorporating real-time rainfall data from a sensor network within the catchment into the forecasted meteorological input data. The accuracy of the model in the decision-making process was assessed using the contingency table and its metrics.
The predictive model gave reasonable outputs to support appropriate decision making for public health protection. Scenario 1 provided real-time predictions that, on 77% of instances during the study period where both predicted and E. coli concentrations were available, would correctly inform a beach manager to either take action to mitigate for poor bathing water quality or take no action. However, Scenario 1 also provided data to support a decision to take action (when none was necessary – a type I error) in 4% of instances and to take no action (when action was required – a type II error) in 19% of the instances analysed. Type II errors are critical in terms of public health protection given that for this error, bathers can be exposed to risks from poor bathing water quality. Scenario 2, on the other hand, provided predictions that would support correct management actions for 79% of the instances but would result in type I and type II errors for 4% and 17% of the instances respectively.
Comparison of Scenarios 1 and 2 for this study indicate that Scenario 2 gave a marginally better overall performance in terms of supporting correct management decisions, as it provided data that could result in a lower occurrence of the more critical type II errors.
Given that the 28 member states of the European Union are required to engage with the public health provisions of the revised Bathing Water Directive, issues of compliance, pertaining particularly to the management of bathing water resources, remain topical. Decision supports for managing bathing waters in the context of the Directive are likely to become the focus of much attention and although, the current study has been validated in bathing waters off the east coast of Ireland, the approach of using a deterministic and integrated catchment-coastal model for such purposes is easily transferable to other bathing water jurisdictions.
•The study explores the use of a water quality prediction tool for beach management.•The tool was used to provide a five-day forecast of Escherichia coli at Bray beach, Ireland.•Predictions were based on rainfall forecasts only and forecasts improved with data.•Both scenarios gave reasonable E. coli predictions.•Improved forecast scenario resulted in marginally improved water quality predictions.
Background: To confirm whether shellfish are suitable for consumption, the quality of seawater and shellfish in shellfish-producing areas must be assessed regularly. This study was conducted to ...evaluate the bacterial quality on the Changseon area, containing a designated shellfish-producing area, in Korea during 2011-2013.
Result: Even though many inland pollutants near the area were identified, they showed no significant impact on the designated area and the shellfish therein. The concentrations of fecal bacteria in all the seawater and mussel samples from the designated area during the harvesting season were within the standards of various countries. Pathogenic bacteria were not detected in any of the mussel samples. In our previous study, the hazardous metal levels in all the mussels from the same area were also within the limits of different countries.
Conclusion: The mussel products in this area are suitable for consumption based on fecal pollution, pathogenic bacteria, and also heavy metals.
► Distribution of resistance bacteria and genes in polluted environments of Lake Geneva. ► WWTP is the source of (in)organic pollutants, antibiotics, and antibiotic-resistant bacteria. ► The Bay of ...Vidy can be considered as a reservoir of bacteria multiple resistance genes. ► The
aadA gene resistant found prior to WWTP input, may be considered as an emerging contaminant.
This study investigates faecal indicator bacteria (FIB), multiple antibiotic resistant (MAR), and antibiotic resistance genes (ARGs), of sediment profiles from different parts of Lake Geneva (Switzerland) over the last decades. MARs consist to expose culturable
Escherichia coli (EC) and
Enterococcus (ENT) to mixed five antibiotics including Ampicillin, Tetracycline, Amoxicillin, Chloramphenicol and Erythromycin. Culture-independent is performed to assess the distribution of ARGs responsible for
, β-lactams (
blaTEM; Amoxicillin/Ampicillin)
, Streptomycin/Spectinomycin (
aadA)
, Tetracycline (
tet) Chloramphenicol (
cmlA) and Vancomycin (
van). Bacterial cultures reveal that in the sediments deposited following eutrophication of Lake Geneva in the 1970s, the percentage of MARs to five antibiotics varied from 0.12% to 4.6% and 0.016% to 11.6% of total culturable EC and ENT, respectively. In these organic-rich bacteria-contaminated sediments, the
blaTEM resistant of FIB varied from 22% to 48% and 16% to 37% for EC and ENT respectively, whereas the positive PCR assays responsible for tested ARGs were observed for EC, ENT, and total DNA from all samples. The
aadA resistance gene was amplified for all the sediment samples, including those not influenced by WWTP effluent water. Our results demonstrate that bacteria MARs and ARGs highly increased in the sediments contaminated with WWTP effluent following the cultural eutrophication of Lake Geneva. Hence, the human-induced changing limnological conditions highly enhanced the sediment microbial activity, and therein the spreading of antibiotic resistant bacteria and genes in this aquatic environment used to supply drinking water in a highly populated area. Furthermore, the presence of the antibiotic resistance gene
aadA in all the studied samples points out a regional dissemination of this emerging contaminant in freshwater sediments since at least the late nineteenth century.
Egerton University (EU) uses Wastewater Stabilization Ponds (WSPs) for wastewater treatment. An adjoining wetland with gravel bed substrate and freesurface flow meant to polish discharge before ...releasing into River Njoro is currently non-operational. The current study aimed at establishing the performance of WSPs in terms of concentration and reduction efficiencies of Faecal Indicator Bacteria (FIB); Total Coliforms (TC) and Escherichia coli (E. coli). Wastewater samples were collected weekly for one month from mid- November to mid-December 2017. Total Coliforms and E. coli were isolated using selective and differential media following Membrane Filtration (MF) method. Colonies were cultured on Chromocult Coliform Agar (CCA) and enumerated using standard procedures for examination of water and wastewater. The results were expressed as Colony Forming Units (CFUs) per 100 ml of the original sample. The inlet showed highest concentration of FIB which reduced along the treatment pathway. Total Coliforms and E. coli ranged between 2.5 × 108 - 2.9 × 1011 and 5.9 × 105 - 1.8 × 1010 CFUs/100 ml respectively with cumulative reduction efficiencies between 2 to 4 log units for E. coli and 2 to 3 log units for TC in the two maturation ponds. Although concentration of FIB in EU WSPs reduces along the treatment pathway, the effluent quality is above recommended international standards for discharge into surface waters. The trend is attributed to lack of frequent monitoring, insufficient maintenance, together with short- circuiting effect due to by-passing of wastewater in the design of the new pond system.
Shellfish-growing areas in rural catchments are occasionally affected by elevated faecal contamination from diffuse sources and may be subject to frequent harvest closures/classification downgrades. ...We combined traditional risk management methods based on sanitary surveys and monitoring of
Escherichia coli
in seawater and shellfish with faecal source tracking, bacterial source apportionment, and hydrometeorological modelling to determine the causes of elevated
E. coli
concentrations contributing to harvest closures in Papanui Inlet (Aotearoa New Zealand). These multiple lines of evidence were used to inform a weight of evidence assessment of bacterial contamination in the inlet. Ruminant livestock was estimated to contribute 80% of the faecal coliform loading. Concentrations of
E. coli
in seawater were low (≤ 87 MPN 100 ml
−1
) whilst concentrations in tuaki/cockles/little neck clams (
Austrovenus stutchburyi
) occasionally exceeded the “Approved” classification limit (230 MPN 100 g
−1
). The most frequent positive genetic markers in seawater were the seagull (
Catellicoccus marimammalium
) (54% of seawater samples), and in shellfish, the bovine and seagull markers (both 12.5% of shellfish samples). Solar radiation was negatively correlated with
E. coli
in tuaki. We found that the growing area is affected by faecal inputs from animal and, to a lesser extent, human (septic tank discharges) sources which elevate contamination to levels detectable in tuaki but not in seawater, particularly in the summer months. The innovative approach can enhance the management of shellfish-growing areas affected by intermittent contamination and enables more targeted action to reduce pollution to improve shellfish water quality.
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