Die-Off of Pathogenic E. Coli O157:h7 in Sewage Contaminated Waters

Easton, John H.; Gauthier, Joseph; Lalor, Melinda M.; Pitt, Robert

doi:10.1111/j.1752-1688.2005.tb03793.x

Cited by 57 publications

(55 citation statements)

References 19 publications

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“…S. enterica serovar Typhimurium/pDs was cultivable from swine manure-amended soils for 55 to 120 days at 10°C and 25°C but only for 25 to 55 days from beef manure-amended soils at these temperatures. Reported survival times of cultivable bacterial pathogens and FIB in field scale studies are similar to those reported in this work (12,39).…”

Section: Resultssupporting

confidence: 76%

“…that antibiotic-resistant strains of S. enterica serovar Newport persisted for longer periods of time than their nonresistant counterparts in manure-amended soils. A fourth explanation may be that organisms enter a viable but not cultivable (VBNC) state, resulting in the appearance of an initial rapid decay, until stressed cells alter their physiology, followed by slower decay of more resilient organisms that remain cultivable, or as cells transition into and out of the VBNC state (8,12,14,27). Other potential sources of this behavior may include predation, biofilm formation, or the acquisition of genetic materials by a subpopulation of fecal bacteria from the native soil microbial community that favor their survival over counterparts that do not similarly adapt.…”

Section: Discussionmentioning

confidence: 99%

“…Such models are often required to describe long-term behavior of manure microorganisms in soils and surface waters (12,39). that antibiotic-resistant strains of S. enterica serovar Newport persisted for longer periods of time than their nonresistant counterparts in manure-amended soils.…”

Section: Discussionmentioning

confidence: 99%

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Decay of Bacterial Pathogens, Fecal Indicators, and Real-Time Quantitative PCR Genetic Markers in Manure-Amended Soils

Rogers

Donnelly

Peed

et al. 2011

Appl Environ Microbiol

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This study examined persistence and decay of bacterial pathogens, fecal indicator bacteria (FIB), and emerging real-time quantitative PCR (qPCR) genetic markers for rapid detection of fecal pollution in manureamended agricultural soils. Known concentrations of transformed green fluorescent protein-expressing Escherichia coli O157:H7/pZs and red fluorescent protein-expressing Salmonella enterica serovar Typhimurium/pDs were added to laboratory-scale manure-amended soil microcosms with moisture contents of 60% or 80% field capacity and incubated at temperatures of ؊20°C, 10°C, or 25°C for 120 days. A two-stage first-order decay model was used to determine stage 1 and stage 2 first-order decay rate coefficients and transition times for each organism and qPCR genetic marker in each treatment. Genetic markers for FIB (Enterococcus spp., E. coli, and Bacteroidales) exhibited decay rate coefficients similar to that of E. coli O157:H7/pZs but not of S. enterica serovar Typhimurium/pDs and persisted at detectable levels longer than both pathogens. Concentrations of these two bacterial pathogens, their counterpart qPCR genetic markers (stx1 and ttrRSBCA, respectively), and FIB genetic markers were also correlated (r ‫؍‬ 0.528 to 0.745). This suggests that these qPCR genetic markers may be reliable conservative surrogates for monitoring fecal pollution from manure-amended land. Hostassociated qPCR genetic markers for microbial source tracking decayed rapidly to nondetectable concentrations, long before FIB, Salmonella enterica serovar Typhimurium/pDs, and E. coli O157:H7/pZs. Although good indicators of point source or recent nonpoint source fecal contamination events, these host-associated qPCR genetic markers may not be reliable indicators of nonpoint source fecal contamination events that occur weeks following manure application on land.Cultivation-based methods for fecal indicator bacteria (FIB) such as Escherichia coli and Enterococcus spp. have long been used to indicate potential public health risks associated with water impacted by human and other animal feces (53). FIB cultivation methods are simple to perform and inexpensive. However, these methods require 18 to 24 h following sampling to generate test results; this allows potential exposure of the public to fecal pathogens in the interim. Regulatory agencies, business owners, and other stakeholders have expressed interest in more rapid and specific methods to identify water quality impairment.Emerging real-time quantitative PCR (qPCR) methods designed to estimate the concentration of fecal pollution by targeting genomic DNA (gDNA) from FIB such as Bacteroidales, Enterococcus spp., and E. coli are now available and can generate test results in just a few hours after sampling (10,16,48). Some of these genetic markers can be correlated to public health risk and may soon be incorporated by the U.S. Environmental Protection Agency into water quality standards in the United States (16,59). These genetic markers may also detect viable but nonculturable (VBNC) cells tha...

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Section: Resultssupporting

confidence: 76%

Section: Discussionmentioning

confidence: 99%

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Decay of Bacterial Pathogens, Fecal Indicators, and Real-Time Quantitative PCR Genetic Markers in Manure-Amended Soils

Rogers

Donnelly

Peed

et al. 2011

Appl Environ Microbiol

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“…Depending on the specifics of the facility permit and wastewater class, these exceedances may be acceptable in some cases. Studies have shown that FIB survival in surface waters varies from hours to days or even months if protected by sediments which make identifying the source of the FIB concentrations difficult [37,38]. The decay rate of FIB in surface water is a function of many ecological influences; therefore, water quality management, best management plan (BMP) development, watershed modeling, and risk assessment practices need to incorporate better methods as to how FIB interact with the environment, and furthermore, how well FIB accurately model true pathogenic concentrations in the watershed [16,17].…”

Section: Discussionmentioning

confidence: 99%

Fecal Coliform and E. coli Concentrations in Effluent-Dominated Streams of the Upper Santa Cruz Watershed

Sanders

Yuan

Pitchford

2013

Water

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This study assesses the water quality of the Upper Santa Cruz Watershed in southern Arizona in terms of fecal coliform and Escherichia coli (E. coli) bacteria concentrations discharged as treated effluent and from nonpoint sources into the Santa Cruz River and surrounding tributaries. The objectives were to (1) assess the water quality in the Upper Santa Cruz Watershed in terms of fecal coliform and E. coli by comparing the available data to the water quality criteria established by Arizona, (2) to provide insights into fecal indicator bacteria (FIB) response to the hydrology of the watershed and (3) to identify if point sources or nonpoint sources are the major contributors of FIB in the stream. Assessment of the available wastewater treatment plant treated effluent data and in-stream sampling data indicate that water quality criteria for E. coli and fecal coliform in recreational waters are exceeded at all locations of the Santa Cruz River. For the wastewater discharge, 13%-15% of sample concentrations exceeded the 800 colony forming units (cfu) per 100 mL sample maximum for fecal coliform and 29% of samples exceeded the full body contact standard of 235 cfu/100 mL established for E. coli; while for the in-stream grab samples, 16%-34% of sample concentrations exceeded the 800 cfu/100 mL sample maximum for fecal coliforms and 34%-75% of samples exceeded the full body contact standard of 235 cfu/100 mL established for E. coli. Elevated fecal coliform and E. coli concentrations were positively correlated with periods of increased streamflow from rainfall. FIB concentrations observed in-stream are significantly greater (p-value < 0.0002) than wastewater treatment plants effluent concentrations; therefore, water quality managers should focus on nonpoint OPEN ACCESSWater 2013, 5 244 sources to reduce overall fecal indicator loads. Findings indicate that fecal coliform and E. coli concentrations are highly variable, especially along urban streams and generally increase with streamflow and precipitation events. Occurrences of peaks in FIB concentrations during baseflow conditions indicate that further assessment of ecological factors such as interaction with sediment, regrowth, and source tracking are important to watershed management.

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“…First-order rate constants (k) were calculated for upper layer E. coli population declines for each , which is within the 0.00104 -3.40 d -1 range of literature inactivation rates for E. coli in freshwater systems (Crane and Moore, 1986;Flint, 1987;Davies and Evison, 1991;Easton et al, 2005). The huge range in inactivation rate reflects the diversity of environmental conditions studied.…”

Section: In-situ Inactivation Studiesmentioning

confidence: 99%

Inactivation of Escherichia coli During Storage of Irrigation Water in Agricultural Reservoirs

Murphy¹,

Jamieson²,

Stratton³

et al. 2010

Canadian Water Resources Journal

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Microbial contamination of surface waters is one of the most important water quality issues affecting the agricultural sector in Nova Scotia, Canada. Most farmers who irrigate in the province draw their source water directly from streams and rivers. One mode of pathogen transmission is the irrigation of horticultural crops with contaminated water. The extended storage of irrigation water prior to crop application could minimize this risk. Natural inactivation processes could, depending on the source water characteristics and length of storage time, reduce bacteria levels to acceptable use standards. The purpose of this project was to study bacterial population dynamics, specifically those of Escherichia coli, in shallow irrigation water reservoirs. Experiments, involving a series of dialysis tube survival studies, were conducted from May through September of 2006 in an operational farm reservoir to examine microbial inactivation kinetics. It was found that E. coli populations in the cool, lower layer (depth ≈ 3 m) did not decline, while populations in the warm upper layer (depth ≈ 1.0 m) experienced significant reductions over a period of several days. An inactivation model was calibrated and used to develop conservative estimates of T 90 , T 99 , and T 99.9 values for environmental conditions typical of the Annapolis Valley of Nova Scotia. If a shallow reservoir was well mixed to prevent gradients in temperature and dissolved oxygen, storage of irrigation water for a period of at least two weeks would reduce bacterial numbers by at least three logs during the growing season in Nova Scotia.

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Die-Off of Pathogenic E. Coli O157:h7 in Sewage Contaminated Waters

Cited by 57 publications

References 19 publications

Decay of Bacterial Pathogens, Fecal Indicators, and Real-Time Quantitative PCR Genetic Markers in Manure-Amended Soils

Decay of Bacterial Pathogens, Fecal Indicators, and Real-Time Quantitative PCR Genetic Markers in Manure-Amended Soils

Fecal Coliform and E. coli Concentrations in Effluent-Dominated Streams of the Upper Santa Cruz Watershed

Inactivation of Escherichia coli During Storage of Irrigation Water in Agricultural Reservoirs

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