Introduction: Shellfish are filter-feeding aquatic animals that can bioaccumulate pathogens from ... more Introduction: Shellfish are filter-feeding aquatic animals that can bioaccumulate pathogens from contaminated water, thereby posing a potential risk of infection to human consumers. Therefore, the prevention of these infections is of significant public health importance. An environmental study was carried out to investigate the seasonality of bioaccumulation of bacteriophages and fecal bacterial indicators in mussels (Mytilus edulis) and their overlying waters at a site in Southeast England, United Kingdom. Methods: Freshly collected mussels and samples of overlying water were analyzed using standard microbiological methods of a period of twelve months. The concentration of fecal coliforms, enterococci and E.coli were determined by membrane filtration and most probable number methods (MPN), while the concentration of somatic coliphages (WG5), F RNA phages (WG49) and human-specific Bacteroides fragilis phages (GB124) were determined by direct plaque assay using a standardized double ...
Greater incidence of storm events, which can lead to greater contamination of surface waters by h... more Greater incidence of storm events, which can lead to greater contamination of surface waters by human and animal faeces, are a predicted feature of climate change in parts of Europe and elsewhere. The aim of this study was to combine the use of a novel quantitative microbial source tracking (QMST) method with established water quality monitoring procedures during an intense summer storm event in a rural UK river catchment, to establish dominant sources of faecal pollution. One-litre grab samples of river water were collected every 12 h for a period of seven days from three sampling sites on the Bevern Stream (a tributary of the Sussex Ouse). All samples were tested for a range of chemophysical and bacteriological parameters, and also for phage-lysis of a human specific strain of Bacteroides spp. GB-124. Presumptive levels of Escherichia coli and intestinal enterococci were statistically significantly (p-value<0.05) higher during the storm event, compared with dry weather conditio...
A pilot-scale irrigation scheme was set up in South-West Portugal to investigate the causes of em... more A pilot-scale irrigation scheme was set up in South-West Portugal to investigate the causes of emitter clogging which has been observed when waste stabilisation pond effluents are used for drip irrigation of crops. During field trials over a period of two growing seasons, the ...
David Diston, Steve Mitchell. ... and host two National Nature Reserves that are of specific avia... more David Diston, Steve Mitchell. ... and host two National Nature Reserves that are of specific avian importance for both over-wintering and breeding bird populations [particularly Vanellus vanellus (Lapwing) and Gallinago gallinago (Snipe); Gasca-tucker and Acreman, undated]. ...
Faecal pollution of recreational bathing waters may derive from point sources of various wastewat... more Faecal pollution of recreational bathing waters may derive from point sources of various wastewaters or from more diffuse sources such as run-off of agricultural wastes. The paper describes the application of population similarity studies to the enterococcal flora of various animal faeces and municipal wastewaters as a means of distinguishing human from animal faecal material. A simplified phenotypic testing technique (PhenePlate, PhP) was used to study the fermentation kinetics of eleven carbohydrates by all bacterial isolates. Enterococcal isolates (1,766) from six sources were investigated. Enterococcal population diversity (measured as Simpson&#39;s Diversity Index) in wastewater samples was high (mean D(i) = 0.95) compared with those of non-human faeces. The mean diversity of isolates in seabird faeces was 0.72, in sheep and donkey faeces 0.44, in dog faeces 0.42 and in cattle faeces 0.32. Analysis of population similarity coefficients demonstrated that faeces from sheep and cattle showed the greatest similarity (S(p) = 0.72). Sheep and cattle faeces demonstrated a low similarity to municipal wastewater samples. This would suggest that population similarity studies might be a useful tool for distinguishing the relative contributions of municipal wastewater and agricultural run-off to bathing water pollution. The PhP procedure identified a specific PhP type that appears to have high specificity to non-human faeces. It may, therefore, represent an important tool in source tracking. Additional phenotypic and genotypic analysis of PhP types that demonstrate a high degree of source specificity is required. The benefits and limitations of the use of population similarity studies to distinguish pollution sources are discussed in comparison with other source tracking approaches and the implications of these developments for future European Union legislation on the quality of bathing waters are discussed.
Introduction: Shellfish are filter-feeding aquatic animals that can bioaccumulate pathogens from ... more Introduction: Shellfish are filter-feeding aquatic animals that can bioaccumulate pathogens from contaminated water, thereby posing a potential risk of infection to human consumers. Therefore, the prevention of these infections is of significant public health importance. An environmental study was carried out to investigate the seasonality of bioaccumulation of bacteriophages and fecal bacterial indicators in mussels (Mytilus edulis) and their overlying waters at a site in Southeast England, United Kingdom. Methods: Freshly collected mussels and samples of overlying water were analyzed using standard microbiological methods of a period of twelve months. The concentration of fecal coliforms, enterococci and E.coli were determined by membrane filtration and most probable number methods (MPN), while the concentration of somatic coliphages (WG5), F RNA phages (WG49) and human-specific Bacteroides fragilis phages (GB124) were determined by direct plaque assay using a standardized double ...
Greater incidence of storm events, which can lead to greater contamination of surface waters by h... more Greater incidence of storm events, which can lead to greater contamination of surface waters by human and animal faeces, are a predicted feature of climate change in parts of Europe and elsewhere. The aim of this study was to combine the use of a novel quantitative microbial source tracking (QMST) method with established water quality monitoring procedures during an intense summer storm event in a rural UK river catchment, to establish dominant sources of faecal pollution. One-litre grab samples of river water were collected every 12 h for a period of seven days from three sampling sites on the Bevern Stream (a tributary of the Sussex Ouse). All samples were tested for a range of chemophysical and bacteriological parameters, and also for phage-lysis of a human specific strain of Bacteroides spp. GB-124. Presumptive levels of Escherichia coli and intestinal enterococci were statistically significantly (p-value<0.05) higher during the storm event, compared with dry weather conditio...
A pilot-scale irrigation scheme was set up in South-West Portugal to investigate the causes of em... more A pilot-scale irrigation scheme was set up in South-West Portugal to investigate the causes of emitter clogging which has been observed when waste stabilisation pond effluents are used for drip irrigation of crops. During field trials over a period of two growing seasons, the ...
David Diston, Steve Mitchell. ... and host two National Nature Reserves that are of specific avia... more David Diston, Steve Mitchell. ... and host two National Nature Reserves that are of specific avian importance for both over-wintering and breeding bird populations [particularly Vanellus vanellus (Lapwing) and Gallinago gallinago (Snipe); Gasca-tucker and Acreman, undated]. ...
Faecal pollution of recreational bathing waters may derive from point sources of various wastewat... more Faecal pollution of recreational bathing waters may derive from point sources of various wastewaters or from more diffuse sources such as run-off of agricultural wastes. The paper describes the application of population similarity studies to the enterococcal flora of various animal faeces and municipal wastewaters as a means of distinguishing human from animal faecal material. A simplified phenotypic testing technique (PhenePlate, PhP) was used to study the fermentation kinetics of eleven carbohydrates by all bacterial isolates. Enterococcal isolates (1,766) from six sources were investigated. Enterococcal population diversity (measured as Simpson&#39;s Diversity Index) in wastewater samples was high (mean D(i) = 0.95) compared with those of non-human faeces. The mean diversity of isolates in seabird faeces was 0.72, in sheep and donkey faeces 0.44, in dog faeces 0.42 and in cattle faeces 0.32. Analysis of population similarity coefficients demonstrated that faeces from sheep and cattle showed the greatest similarity (S(p) = 0.72). Sheep and cattle faeces demonstrated a low similarity to municipal wastewater samples. This would suggest that population similarity studies might be a useful tool for distinguishing the relative contributions of municipal wastewater and agricultural run-off to bathing water pollution. The PhP procedure identified a specific PhP type that appears to have high specificity to non-human faeces. It may, therefore, represent an important tool in source tracking. Additional phenotypic and genotypic analysis of PhP types that demonstrate a high degree of source specificity is required. The benefits and limitations of the use of population similarity studies to distinguish pollution sources are discussed in comparison with other source tracking approaches and the implications of these developments for future European Union legislation on the quality of bathing waters are discussed.
This study proposes that calculating and interpreting removal coefficients (K20) for bacteriophag... more This study proposes that calculating and interpreting removal coefficients (K20) for bacteriophages in activated sludge (AS) and trickling filter (TF) systems using stochastic modelling may provide important information that may be used to estimate the removal of phages in such systems using simplified models. In order to achieve this, 14 samples of settled wastewater and post-secondary sedimentation wastewater were collected every 2 weeks, over a 6-month period (May to November), from two AS and two TF systems situated in southern England. Initial results have demonstrated that the removal of somatic coliphages in both AS and TF systems is considerably higher than that of F-RNA coliphages, and that AS more effectively removes both phage groups than TF. The results have also demonstrated that K20 values for phages in AS are higher than in TF, which could be justified by the higher removal rates observed in AS and the models assumed for both systems. The research provides a suggested framework for calculating and predicting removal rates of pathogens and indicator organisms in wastewater treatment systems using simplified models in order to support integrated water and sanitation safety planning approaches to human health risk management.
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Papers by Huw Taylor