Time since faecal deposition influences mobilisation of culturable E. coli and intestinal enterococci from deer, goose and dairy cow faeces

Abstract

Mobilisation is a term used to describe the supply of a pollutant from its environmental source, e.g., soil or faeces, into a hydrological transfer pathway. The overarching aim of this study was to determine, using a laboratory-based approach, whether faecal indicator bacteria (FIB) are hydrologically mobilised in different quantities from a typical agricultural, wildlife and wildfowl source, namely dairy cattle, red deer and greylag goose faeces. The mobilisation of FIB from fresh and ageing faeces under two contrasting temperatures was determined, with significant differences in the concentrations of both E. coli and intestinal enterococci lost from all faecal sources. FIB mobilisation from these faecal matrices followed the order of dairy cow > goose > deer (greatest to least, expressed as a proportion of the total FIB present). Significant changes in mobilisation rates from faecal sources over time were also recorded and this was influenced by the temperature at which the faecal material had aged over the course of the 12-day study. Characterising how indicators of waterborne pathogens are mobilised in the environment is of fundamental importance to inform models and risk assessments and develop effective strategies for reducing microbial pollution in catchment drainage waters and associated downstream impacts. Our findings add quantitative evidence to support the understanding of FIB mobilisation potential from three important faecal sources in the environment.

Persistence of E. coli in Streambed Sediment Contaminated with Faeces from Dairy Cows, Geese, and Deer: Legacy Risks to Environment and Health

“…All faeces were collected fresh for use in experiments, and the provenance of all faecal sources and sample collection is detailed in full in Afolabi et al [ 10 ]. Briefly, fresh dairy faeces were collected from the livestock housing of a conventional dairy farm in Stirlingshire, Scotland.…”

“…In addition to agricultural and sewage sources, FIO loading of watercourses and streambed sediments can also originate from wildlife and wildfowl. Populations of deer, geese, and other wildlife may defecate directly into an aquatic environment, or their faecal depositions to land can be disrupted following rainfall events, with a proportion of FIOs subsequently mobilised and transferred to receiving waters [ 10 ]. Studies have reported on black-tailed deer and Canadian geese as contributors of FIOs in environmental matrices [ 11 , 12 ], and there are reports of increased FIO inputs to sediment stores of aquatic environments in catchments that can result from wildlife activity [ 13 ].…”