Download or read book Pathogenic Bacteria and Microbial Source Tracking Markers in Brandywine Creek Basin Pennsylvania and Delaware 2009 10 written by Joseph W. Duris and published by Geological Survey (USGS). This book was released on 2011-01-01 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pathogenic Bacteria and Microbial Source Tracking Markers in Brandywine Creek Basin Pennsylvania and Delaware 2009 10 written by Joseph W Duris and published by Scholar's Choice. This book was released on 2015-02-16 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Download or read book Pathogenic bacteria and microbial source tracking markers in Brandywine Creek Basin Pennsylvania and Delaware 2009 10 written by and published by . This book was released on 2011 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microbial Source Tracking written by Michèle Gourmelon and published by Frontiers Media SA. This book was released on 2022-01-18 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microbial Source Tracking of Bacteroidales and Human Virus Monitoring in Calleguas Creek Watershed written by Beverly Jo Kildare and published by . This book was released on 2005 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Utility of Microbial Source tracking Markers for Assessing Fecal Contamination in the Portage River Watershed Northwestern Ohio 2008 written by Christopher M. Kephart and published by . This book was released on 2010 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microbial Source Tracking written by Natsuko N. Merrick and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The molecular based, quantitative PCR assay was compared with the traditional viable E. coli count assay and a significant (P
Download or read book Evaluation of Bacteroidales 16S RRNA Genetic Markers as a Microbial Source Tracking Tool in a Canadian Agricultural Watershed written by Christina M. Ridley and published by . This book was released on 2012 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Waterborne pathogen presence caused by fecal pollution is a leading cause of morbidity and mortality worldwide. In developed countries, this problem can result in waterborne outbreaks. Research suggests that there is a need for better fecal indicators because current methods (total coliforms and E. coli) are insufficient. This study investigated Bacteroidales 16S rRNA markers as a microbial source tracking tool in an agricultural watershed. Correlations between pathogens and markers were also investigated. Water quality monitoring was conducted following assay validation of ruminant-, bovine-, human-specific, and universal Bacteroidales markers. Results revealed a positive relationship between E. coli and the universal marker. Ruminant- and bovine-specific marker detection was associated with increased runoff due to precipitation; however, the human associated marker was not detected. Furthermore, no correlations between Campylobacter, Salmonella, or E. coli O157:H7 could be made. Consequently, these techniques have potential to become a powerful tool; however, further research is needed
Download or read book Focus on Microbial Source Tracking written by Environmental Assessment Program (Wash.) and published by . This book was released on 2012 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a Rapid Method for a Human Pollution Source Tracking Marker Using Enterococcus Surface Protein esp in E Faecium written by Lekha Satheesh Kumar and published by . This book was released on 2007 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microbial Source Tracking written by Eyob Mazengia and published by . This book was released on 1998 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Host Specific Microbial Source Tracking and Quantification Using a Partial 16SrRNA Sequence of Bacteroides on the Finley River a Tributary of the James River in Southwest Missouri written by Neil J. Van Asch and published by . This book was released on 2009 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial source tracking (MST) is a general term given to any process which aims to determine the source of microbial contamination found in an environmental (usually water) sample. These methods include both phenotypic and genotypic strategies. In this study, quantitative PCR was used to evaluate water samples for species specific (cow and human) Bacteroides in the Finley River. The Finley River is susceptible to impacts from both bovine and humans as it flows through farmland and urban areas. Water samples were collected from sites identified in a previous study that had high E. coli levels. Two samples were collected at each site (One sample for enumeration of E. coli and the other to assay for Bacteroides). Sampling was done approximately three times per month for one year. For each sampling event, pH, DO, turbidity, water temperature, flow rate, and rainfall were recorded. The results showed lower than expected cow markers throughout the sampling period; while human markers were much more prevalent than cow markers during the drier (and warmer) months. A correlation was found between human specific Bacteroides markers and E. coli at one site, but not at either of the other two sites. This method affords more informative surveillance data to area health departments so more appropriate remediation strategies can be developed.
Download or read book Development of a Molecular Method for Microbial Source Tracking written by Amy L. Diehl and published by . This book was released on 2006 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Based Methods to Detect Viable Bacterial Pathogens in Source Waters written by Avid Banihashemi Jahromi and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Humans can be exposed to waterborne bacterial pathogens and numerous outbreaks have been reported involving these microorganisms around the world. Many different enteric pathogens can be found in source waters used for drinking water. Assessing these pathogens and their possible threat to public health has always been important. Waterborne pathogens can be difficult to detect, and despite a large variety of recognized microbial detection techniques, the cause of many outbreaks has not been unidentified. Effective and rapid pathogen detection techniques are required to achieve reliable data for microbial source water quality, outbreak investigations, and for drinking water treatment efficacy monitoring. Bacteria have long been detected using classical culture-based methods, with the rationale that living cells are able to grow/replicate. However, many pathogenic bacteria in source waters may turn into viable but not culturable (VBNC) cells and are thus undetectable by growth-based methodologies. Alternatively, PCR-based techniques have been developed to detect both non-culturable and culturable bacteria. Yet with these techniques, post-death DNA persistency can inaccurately overestimate the number of viable cells. This problem may be circumvented by an alteration to the PCR procedure that is reported to be able to block PCR amplification of DNA that originates from dead cells. This alteration involves a chemical pre-treatment step prior to PCR using a photoreactive intercalating dye, propidium monoazide (PMA). In this research, a successful modification was made to the PMA-PCR method that can result in substantial suppression of the PCR signal from dead cells, and provide results that can more accurately measure bacterial pathogen viability. PMA-PCR was applied to high concentrations (1 × 107 cells mL-1) of heat-killed cells of Salmonella enterica and Campylobacter jejuni. Using PMA-PCR in combination with primers that amplified a relatively short fragment of the S. enterica invA gene (119 bp), only a 3-log reduction of the dead cell PCR signal was obtained. Similarly, for C. jejuni using PCR primers that amplified a relatively short fragment of DNA (174 bp of cpn60 gene), only a 1-log reduction of the PCR signal was observed for dead cells. Therefore, PMA treatment followed by PCR amplification of short DNA fragments resulted in incomplete signal inhibition of heat killed Salmonella and Campylobacter. To further investigate how PCR conditions can affect the ability of PMA to inhibit PCR amplification, primers were then used that could amplify a larger fragment of DNA. PCR amplification of a longer DNA fragment (1614 bp of invA gene for S. enterica and 1512 bp of cpn60 gene for C. jejuni) strongly suppressed the signal (7 log reduction) for both heat-killed Salmonella and Campylobacter. For UV-treated S. enterica and C. jejuni, short amplicon PMA-PCR showed no or very low PCR signal reduction, in part due to intact membranes directly after UV irradiation. Long amplicon qPCR, however, resulted in dead cell signal removal and PMA pretreatment had no effect on PCR signal suppression. This study used quantitative PCR and the PMA-PCR viability assays to evaluate the levels and occurrences of four groups of pathogenic bacteria in surface water samples from two locations on the Grand River, Ontario, Canada, to demonstrate the reliability of the PMA-PCR technique for the enumeration of viable cells. The bacterial groups investigated included S. enterica, thermophilic Campylobacter, Escherichia coli O157:H7, and Arcobacter butzleri. Small numbers of dead cells (not more than 0.5 log 100 mL-1) were present, detected as the difference between PMA-PCR and PCR without PMA treatment. In this particular river, pathogen enumeration by PCR was only slightly influenced by false positive signal detection due to the presence of dead cells or extracellular DNA and reliable bacterial pathogen detection could be attained by PCR without PMA pretreatment. Viable A. butzleri were detected at elevated concentrations (up to 4.8 log cells per 100 mL) in the Grand River. Arcobacter has not been previously studied in the Grand River and this is one of the few studies that have quantitatively assessed Arcobacter in the environment. This suggests that additional research is required on the pathogenicity of this organism and its occurrence in water. In the next stage of this research, both the improved viability assay (long amplicon PMA-PCR) and conventional quantitative PCR were applied to investigate the survival trends of selected enteric bacterial pathogens including Yersinia enterocolitica, S. enterica, C. jejuni, and A. butzleri. The target bacteria were inoculated into sterile or non-sterile river water to study the impact of background microbiota on cell survival. These experiments were perfomed at 3 different temperatures (5, 15, and 25°C) and at high/low dissolved oxygen (DO) concentrations (for C. jejuni, and A. butzleri only) to evaluate the effect of these potential environmental stresses on bacterial survival trends. The results indicated that the autochthonous microbiota in river water had a significant effect on the bacterial die-off. Although lower temperatures enhanced bacterial survival in non-sterile river water, it was found that PCR may overestimate the effect of temperature on survival and that the PCR viability assays (PMA-PCR) could more accurately measure the impact of temperature. The survival of viable C. jejuni was adversely affected by high DO levels only at a low temperature (5°C) and this effect was observed only when the PMA-PCR viability assay was applied. A. butzleri survival was not affected by water DO levels. This research provides an improved understanding of viable/active enteric waterborne bacteria and their survival in the aquatic microcosms as well as reliable data to better elucidate the effect of environmental factors on the occurrence of pathogenic bacteria. It can also offer valuable information for microbial risk assessments used by regulators and decision makers.
Download or read book Northeast Region Bacteria Source Tracking 2009 Results written by Jenny Birnbaum and published by . This book was released on 2009 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Urban Stormwater Management in the United States written by National Research Council and published by National Academies Press. This book was released on 2009-03-17 with total page 611 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rapid conversion of land to urban and suburban areas has profoundly altered how water flows during and following storm events, putting higher volumes of water and more pollutants into the nation's rivers, lakes, and estuaries. These changes have degraded water quality and habitat in virtually every urban stream system. The Clean Water Act regulatory framework for addressing sewage and industrial wastes is not well suited to the more difficult problem of stormwater discharges. This book calls for an entirely new permitting structure that would put authority and accountability for stormwater discharges at the municipal level. A number of additional actions, such as conserving natural areas, reducing hard surface cover (e.g., roads and parking lots), and retrofitting urban areas with features that hold and treat stormwater, are recommended.
Download or read book Scientific Investigations Report written by Sharon E. Kroening and published by . This book was released on 2004 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
