Relative Decay of Fecal Indicator Bacteria and Human-Associated Markers: A Microcosm Study Simulating Wastewater Input into Seawater and Freshwater

Jeanneau, Laurent; Solecki, O.; Wéry, Nathalie; Jardé, Émilie; Gourmelon, Michèle; Communal, Pierre-Yves; Jadas-Hécart, Alain; Caprais, Marie‐Paule; Gruau, Gérard; Pourcher, Anne‐Marie

doi:10.1021/es203019y

Cited by 71 publications

(65 citation statements)

References 35 publications

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“…In contrast, slower decay rates of Bacteroidales markers exposed to sunlight have been observed by others [105,108,110]. Studies also reported that the decay rates of the several Bacteroides markers including human-specific Bacteroides (BsteriF1, BuniF2, GenBac3, HF183, HF134, and HumM2) in freshwater were somewhat greater than the corresponding decay rate in seawater [106,112]. Bae and Wuertz [108] used propidium monoazide (PMA)-qPCR to differentiate between live and dead cells or extracellular DNA.…”

Section: Decay Of Human-specific Bacteroides Markers In Environmentalmentioning

confidence: 98%

Current Status of Marker Genes of Bacteroides and Related Taxa for Identifying Sewage Pollution in Environmental Waters

Ahmed

Hughes

Harwood

2016

Water

111

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Abstract:Microbial source tracking (MST) endeavors to determine sources of fecal pollution in environmental waters by capitalizing on the association of certain microorganisms with the gastrointestinal tract and feces of specific animal groups. Several decades of research have shown that bacteria belonging to the gut-associated order Bacteroidales, and particularly the genus Bacteroides, tend to co-evolve with the host, and are, therefore, particularly suitable candidates for MST applications. This review summarizes the current research on MST methods that employ genes belonging to Bacteroidales/Bacteroides as tracers or "markers" of sewage pollution, including known advantages and deficiencies of the many polymerase chain reaction (PCR)-based methods that have been published since 2000. Host specificity is a paramount criterion for confidence that detection of a marker is a true indicator of the target host. Host sensitivity, or the prevalence of the marker in feces/waste from the target host, is necessary for confidence that absence of the marker is indicative of the absence of the pollution source. Each of these parameters can vary widely depending on the type of waste assessed and the geographic location. Differential decay characteristics of bacterial targets and their associated DNA contribute to challenges in interpreting MST results in the context of human health risks. The HF183 marker, derived from the 16S rRNA gene of Bacteroides dorei and closely related taxa, has been used for almost two decades in MST studies, and is well characterized regarding host sensitivity and specificity, and in prevalence and concentration in sewage in many countries. Other markers such as HumM2 and HumM3 show promise, but require further performance testing to demonstrate their widespread utility. An important limitation of the one-marker-one-assay approach commonly used for MST is that given the complexities of microbial persistence in environmental waters, and the methodological challenges of quantitative PCR (qPCR) in such samples, the absence of a given marker does not ensure the absence of fecal pollution in the source water. Approaches under development, such as microarray and community analysis, have the potential to improve MST practices, thereby increasing our ability to protect human and ecosystem health.

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Section: Decay Of Human-specific Bacteroides Markers In Environmentalmentioning

confidence: 98%

Current Status of Marker Genes of Bacteroides and Related Taxa for Identifying Sewage Pollution in Environmental Waters

Ahmed

Hughes

Harwood

2016

Water

111

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“…Ideally, MST markers and FIB will have similar fates and transport behaviors governed by their concentrations in polluting matrices, extraintestinal survival, growth rates after excretion, and mobility in the environment (10,11). Of these factors, survival of FIB and MST markers plays an integral role in determining their fate and transport in the environment, since survival can strongly influence prevalence in both fecal sources and water environments.…”

mentioning

confidence: 99%

Decay of Fecal Indicator Bacterial Populations and Bovine-Associated Source-Tracking Markers in Freshly Deposited Cow Pats

Oladeinde

Bohrmann

Wong

et al. 2014

Appl Environ Microbiol

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Understanding the survival of fecal indicator bacteria (FIB) and microbial source-tracking (MST) markers is critical to developing pathogen fate and transport models. Although pathogen survival in water microcosms and manure-amended soils is well documented, little is known about their survival in intact cow pats deposited on pastures. We conducted a study to determine decay rates of fecal indicator bacteria (Escherichia coli and enterococci) and bovine-associated MST markers (CowM3, Rum-2-bac, and GenBac) in 18 freshly deposited cattle feces from three farms in northern Georgia. Samples were randomly assigned to shaded or unshaded treatment in order to determine the effects of sunlight, moisture, and temperature on decay rates. A general linear model (GLM) framework was used to determine decay rates. Shading significantly decreased the decay rate of the E. coli population (P < 0.0001), with a rate of ؊0.176 day ؊1 for the shaded treatment and ؊0.297 day ؊1 for the unshaded treatment. Shading had no significant effect on decay rates of enterococci, CowM3, Rum-2-bac, and GenBac (P > 0.05). In addition, E. coli populations showed a significant growth rate (0.881 day ؊1 ) in the unshaded samples during the first 5 days after deposition. UV-B was the most important parameter explaining the decay rate of E. coli populations. A comparison of the decay behaviors among all markers indicated that enterococcus concentrations exhibit a better correlation with the MST markers than E. coli concentrations. Our results indicate that bovine-associated MST markers can survive in cow pats for at least 1 month after excretion, and although their decay dynamic differs from the decay dynamic of E. coli populations, they seem to be reliable markers to use in combination with enterococci to monitor fecal pollution from pasture lands. E levated levels of fecal indicator bacteria (FIB) remain the most common cause of impairment in streams and rivers in the United States, with agriculture as the primary source of contamination (1). The federal Clean Water Act defines impaired surface waters as rivers, lakes, or streams that do not meet one or more water quality standards and therefore categorizes these water resources as too polluted for their intended uses. FIB are recommended for water monitoring because of their correlation with gastrointestinal illness (2-4), but they cannot indicate the origin of fecal pollution. This shortcoming is one of the challenges present when attempting to protect and remediate water sources that are impaired due to fecal contamination (5). Emerging libraryand culture-independent microbial source-tracking (MST) methods that target host-associated markers and offer information about the sources of fecal contamination are now used widely by state and federal agencies monitoring water resources (6-9). Information can be used for total maximum daily load (TMDL) development and implementation of remediation practices.Ideally, MST markers and FIB will have similar fates and transport behaviors governed by their co...

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“…However, the validity of the tiered approach depends upon a close correlation between the quantities of the Bacteroidales gene markers and the standard FIB of the target animal species after feces is excreted into the water so that the gene marker detection assay could reliably indicate to the animal species that caused the increase in the monitored level of the standard FIB. As such, the understanding of the relative decay rates of the Bacteroidales gene markers and the standard FIB in water have important implications to their utility in the tiered approach (Dick et al 2010;Jeanneau et al 2012;Tambalo et al 2012).…”

Section: Introductionmentioning

confidence: 99%

“…It is currently not known how the combined effects of the concentration of DO and the intensity of light affect the dynamics of the DNA and RNA of the Bacteroidales gene markers relative to that of the standard FIB, and which type of the markers (DNA vs RNA) would be more suitable to complement the standard FIB in the tiered approach under different DO and light conditions. Thus far, studies on the decay of the Bacteroidales gene markers have been mainly for those associated with human feces (e.g., Savichtcheva et al 2005;Dick et al 2010;Jeanneau et al 2012;Ahmed et al 2014). There are far fewer reports on the decay of the gene markers of other animal sources such as cattle (e.g., Okabe and Shimazu 2007;Tambalo et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Differential utility of the Bacteroidales DNA and RNA markers in the tiered approach for microbial source tracking in subtropical seawater

Liu

Cheng

Wong

et al. 2015

Appl Microbiol Biotechnol

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Source tracking of fecal pollution is an emerging component in water quality monitoring. It may be implemented in a tiered approach involving Escherichia coli and/or Enterococcus spp. as the standard fecal indicator bacteria (FIB) and the 16S rRNA gene markers of Bacteroidales as source identifiers. The relative population dynamics of the source identifiers and the FIB may strongly influence the implementation of such approach. Currently, the relative performance of DNA and RNA as detection targets of Bacteroidales markers in the tiered approach is not known. We compared the decay of the DNA and RNA of the total (AllBac) and ruminant specific (CF128) Bacteroidales markers with those of the FIB in seawater spiked with cattle feces. Four treatments of light and oxygen availability simulating the subtropical seawater of Hong Kong were tested. All Bacteroidales markers decayed significantly slower than the FIB in all treatments. Nonetheless, the concentrations of the DNA and RNA markers and E. coli correlated significantly in normoxic seawater independent of light availability, and in hypoxic seawater only under light. In hypoxic seawater without light, the concentrations of RNA but not DNA markers correlated with that of E. coli. Generally, the correlations between Enterococcus spp. and Bacteroidales were insignificant. These results suggest that either DNA or RNA markers may complement E. coli in the tiered approach for normoxic or hypoxic seawater under light. When light is absent, either DNA or RNA markers may serve for normoxic seawater, but only the RNA markers are suitable for hypoxic seawater.

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Relative Decay of Fecal Indicator Bacteria and Human-Associated Markers: A Microcosm Study Simulating Wastewater Input into Seawater and Freshwater

Cited by 71 publications

References 35 publications

Current Status of Marker Genes of Bacteroides and Related Taxa for Identifying Sewage Pollution in Environmental Waters

Current Status of Marker Genes of Bacteroides and Related Taxa for Identifying Sewage Pollution in Environmental Waters

Decay of Fecal Indicator Bacterial Populations and Bovine-Associated Source-Tracking Markers in Freshly Deposited Cow Pats

Differential utility of the Bacteroidales DNA and RNA markers in the tiered approach for microbial source tracking in subtropical seawater

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