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Source Tracking (source + tracking)

Distribution by Scientific Domains
Life Sciences75%

Terms modified by Source Tracking

  • source tracking methods
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    Selected Abstracts

    ASSESSING LAND USE IMPACTS ON WATER QUALITY USING MICROBIAL SOURCE TRACKING,

    JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 6 2004
    Sharon C. Long
    ABSTRACT: A renewed emphasis on source water protection and watershed management has resulted from recent amendments and initiatives under the Safe Drinking Water Act and the Clean Water Act. Knowledge of the impact of land use choices on source water quality is critical for efforts to properly manage activities within a watershed. This study evaluated qualitative relationships between land use and source water quality and the quantitative impact of season and rainfall events on water quality parameters. High levels of specific conductance tended to be associated with dense residential development, while organic carbon was elevated at several forested sites. Turbidity was generally higher in more urbanized areas. Source tracking indicators were detected in samples where land use types would predict their presence. Coliform levels were statistically different at the 95 percent confidence levels for winter versus summer conditions and dry versus wet weather conditions. Other water quality parameters that varied with season were organic carbon, turbidity, dissolved oxygen, and specific conductance. These results indicate that land use management can be effective for mitigating impacts to a water body; however, year- round, comprehensive data are necessary to thoroughly evaluate the water quality at a particular site. [source]

    Quantitative microbial faecal source tracking with sampling guided by hydrological catchment dynamics

    ENVIRONMENTAL MICROBIOLOGY, Issue 10 2008
    G. H. Reischer
    Summary The impairment of water quality by faecal pollution is a global public health concern. Microbial source tracking methods help to identify faecal sources but the few recent quantitative microbial source tracking applications disregarded catchment hydrology and pollution dynamics. This quantitative microbial source tracking study, conducted in a large karstic spring catchment potentially influenced by humans and ruminant animals, was based on a tiered sampling approach: a 31-month water quality monitoring (Monitoring) covering seasonal hydrological dynamics and an investigation of flood events (Events) as periods of the strongest pollution. The detection of a ruminant-specific and a human-specific faecal Bacteroidetes marker by quantitative real-time PCR was complemented by standard microbiological and on-line hydrological parameters. Both quantitative microbial source tracking markers were detected in spring water during Monitoring and Events, with preponderance of the ruminant-specific marker. Applying multiparametric analysis of all data allowed linking the ruminant-specific marker to general faecal pollution indicators, especially during Events. Up to 80% of the variation of faecal indicator levels during Events could be explained by ruminant-specific marker levels proving the dominance of ruminant faecal sources in the catchment. Furthermore, soil was ruled out as a source of quantitative microbial source tracking markers. This study demonstrates the applicability of quantitative microbial source tracking methods and highlights the prerequisite of considering hydrological catchment dynamics in source tracking study design. [source]

    The persistence of bifidobacteria populations in a river measured by molecular and culture techniques

    JOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2009
    X. Bonjoch
    Abstract Aims:, To determine relative to faecal coliforms (FC) and sulfite-reducing clostridia (SRC), the environmental persistence of natural populations of Bifidobacterium spp. enumerated by culturing and quantitative polymerase chain reaction (q-PCR). Methods and Results:, Dialysis tubing containing river supplemented with overnight cultures of Bifidobacterium adolescentis (BA) and Bifidobacterium dentium (BD) or urban wastewater were suspended in a river for up to 10 days. At intervals, the contents of each dialysis tube were assayed using q-PCR assays for BA and BD, and selective culture media for FC, SRC, total bifidobacteria (TB), sorbitol-fermenting bifidobacteria (SFB) and cultivable BA. Mean summer T90 values were 251 h for SRC, 92 h for FC, 48 h for BA and BD by q-PCR, and 9 h for TB. Conclusions:,Bifidobacterium spp. was the population with the lowest persistence, showing seasonal differences in T90 when measured by culture techniques or by q-PCR. This difference in relative persistence is because of a longer persistence of molecular targets than cultivable cells. Significance and Impact of the Study:, The persistence of a viable bifidobacteria cells is shorter, but the longest persistence of molecular targets. This factor could be used for origin the faecal pollution in water for the development of microbial source tracking (MST). [source]

    Direct comparison of four bacterial source tracking methods and use of composite data sets

    JOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2007
    E.A. Casarez
    Abstract Aims:, Four bacterial source tracking (BST) methods, enterobacterial repetitive intergenic consensus sequence polymerase chain reaction (ERIC-PCR), automated ribotyping using HindIII, Kirby-Bauer antibiotic resistance analysis (KB-ARA) and pulsed-field gel electrophoresis (PFGE) were directly compared using the same collection of Escherichia coli isolates. The data sets from each BST method and from composite methods were compared for library accuracy and their ability to identify water isolates. Methods and Results:, Potential sources of faecal pollution were identified by watershed sanitary surveys. Domestic sewage and faecal samples from pets, cattle, avian livestock, other nonavian livestock, avian wildlife and nonavian wildlife sources were collected for isolation of E. coli. A total of 2275 E. coli isolates from 813 source samples were screened using ERIC-PCR to exclude clones and to maximize library diversity, resulting in 883 isolates from 745 samples selected for the library. The selected isolates were further analysed using automated ribotyping with HindIII, KB-ARA and PFGE. A total of 555 E. coli isolates obtained from 412 water samples were analysed by the four BST methods. A composite data set of the four BST methods gave the highest rates of correct classification (RCCs) with the fewest unidentified isolates than any single method alone. RCCs for the four-method composite data set and a seven-way split of source classes ranged from 22% for avian livestock to 83% for domestic sewage. Two-method composite data sets were also found to be better than individual methods, having RCCs similar to the four-method composite and identification of the same major sources of faecal pollution. Conclusions:, The use of BST composite data sets may be more beneficial than the use of single methods. Significance and Impact of the Study:, This is one of the first comprehensive comparisons using composite data from several BST methods. While the four-method approach provided the most desirable BST results, the use of two-method composite data sets may yield comparable BST results while providing for cost, labour and time savings. [source]