The dynamics of faecal indicator organisms in a temperate river during storm conditions

Abstract

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 theis 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 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 <i>Bacteroides</i> spp. GB-124. Presumptive levels of <i>Escherichia coil</i> and intestinal enterococci were statistically significant (<i>p</i>-value &lt;0.05) higher during the storm event, compared with dry weather conditions. Low recorded levels of phages of <i>Bacteroides</i> GB-124 during the storm event, compared with dry weather conditions, support the hypothesis that the predominant sources of faecal material in the river during the storm event were non-human. Using traditional faecal indicator bacteria and a QMST marker during storm events may improve human health protection protocol

Evaluation of Low-Cost Phage-Based Microbial Source Tracking Tools for Elucidating Human Fecal Contamination Pathways in Kolkata, India

“…Our analyses of sewage samples showed the presence of all the three phage types, with levels of SOMCPH and phages of GB-124 similar to those reported earlier from untreated sewage ( Ebdon et al, 2012 ; Dias et al, 2015 , 2018 ; Purnell et al, 2015 , 2016 ; McMinn et al, 2017 ). As expected, phages of GB-124 were present at lower concentrations than SOMCPH in sewage ( Payan et al, 2005 ; Blanch et al, 2006 ; Ebdon et al, 2007 , 2012 ; Nnane et al, 2012 ; Harwood et al, 2013 ; McMinn et al, 2014 ; Diston and Wicki, 2015 ) and were consistent with concentrations reported from Europe and United States of 3.90 log 10 PFU/100 mL and 2.58 log 10 PFU/100mL, respectively. The SOMCPH concentrations we detected in sewage in Kolkata were also similar to the concentrations observed in Europe [approx.…”

A fully stochastic approach bridging the microscopic behavior of individual microorganisms with macroscopic ensemble dynamics in surface flow networks

“…[7] The model parameters reflect the characteristics of Cryptosporidium parvum oocysts, a waterborne pathogen behind several notable outbreaks of waterborne disease and a subject of many studies [see, e.g., Atherholt et al, 1998;Atwill et al, 2006;Dai and Boll, 2006;Dorner et al, 2006;Searcy et al, 2006]. Cryptosporidium, like many other microbes and chemicals, is heterogeneously distributed in the environment, its transport is driven by random events, it has a low infectious dose and is expensive to monitor [Curriero et al, 2001;Gale, 1998;Nnane et al, 2012;Richardson et al, 1991;Yeghiazarian et al, 2009]. For these reasons, the decision-making process aiming to reduce human exposure to this, and many other pathogens and contaminants, must ultimately rest with mathematical models capable of capturing its occurrence and transport.…”