Download or read book Use of Host specific Molecular Markers in Fecal Source Tracking written by Sarah Strawberry Silkie and published by . This book was released on 2008 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microbial Source Tracking written by Jorge W. Santo Domingo and published by Emerging Issues in Food Safety. This book was released on 2007 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents a state-of-the-art review of the current technology and applications being utilized to identify sources of fecal contamination in waterways. - Serves as a useful reference for researchers in the food industry, especially scientists investigating etiological agents responsible for food contamination. - Provides background information on MST methods and the assumptions and limitations associated with their use. - Covers a broad range of topics related to MST, including environmental monitoring, public health and national security, population biology, and microbial ecology. - Offers valuable insights into future research directions and technology developments.
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 Fecal Bacteroidetes Host Distributions and Environmental Source Tracking written by Linda K. Dick and published by . This book was released on 2004 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contamination of recreational and shellfish waters with fecal pollution is a major water quality issue with associated economic impacts and human health risks. Reliable fecal source identification and rapid, quantitative analyses are essential components of risk assessment. Enteric bacteria that are endemic to specific hosts have a potential role as public health indicators of fecal pollution. Building on previous work to discriminate ruminant and human fecal contamination, we cloned class Bacteroidetes 16S rRNA genes from pig, elk, dog, cat, and seagull fecal DNAs. Unique restriction patterns were identified among clones from each of the host species using Terminal Restriction Fragment Length Polymorphisms (T-RFLP). Clones exhibiting unique patterns were sequenced and analyzed phylogenetically, along with human, horse, and cattle sequences recovered from previous work. The analysis revealed both endemic and cosmopolitan (global) host distributions. The sequence data were used to identify host-specific genetic markers for pig and horse feces, and to design PCR primers that identify these sources of fecal pollution in water. There was a high degree of sequence overlap among the fecal Bacteroidetes of wild and domestic ruminants, and among human, domestic pet, and seagull Bacteroidetes. We compared fecal Bacteroidetes rRNA genes from these hosts using subtractive hybridization, a method that identifies differences between closely related genomes or gene sequences. A Bacteroidetes rDNA marker that distinguishes elk and cow feces was identified, as well as a host-specific marker for dog fecal Bacteroidetes. The four newly designed PCR primers were tested for specificity and sensitivity, and the dog primer was successfully used, along with the human and ruminant-specific primers, in a collaborative study comparing fecal source tracking methods. We also developed a real time Taq nuclease assay for quantification of fecal Bacteroidetes 16S rDNA, and compared it with an EPA-approved enumeration method for the current standard public health indicator, Escherichia coli, in serial dilutions of sewage primary influent. There was a strong, positive correlation between the methods, and the Taq nuclease assay was sensitive and much more rapid than the E. coli assay. PCR source identification and enumeration of fecal Bacteroidetes 16S rDNA show promise for application in a health risk-based analysis of fecal pollution.
Download or read book Evaluation of Selected DNA based Technology in Impaired Watersheds Impacted by Fecal Contamination from Diverse Sources written by Marirosa Molina and published by . This book was released on 2007 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fecal pollution of surface waters is a top reason for impairment, as reported in the U.S. Environmental Protection Agency's report on the quality of the Nations waters. To be able to develop and implement TMDLs for impaired aquatic resources, it is imperative to determine the sources of the contamination. One tool used to determine the sources of bacterial fecal contamination is to apply a microbial source tracking approach to the system of interest. Microbial source tracking (MST) approaches are based on the assumption that specific strains of bacteria, genetic fingerprints, or DNA-based markers are associated with specific host species. Because accurate source identification of fecal contamination is essential in MST, more sensitive, selective and reliable molecular markers are required. The two types of genotypic methods that have been applied widely in a variety of environments can be classified as library-independent (LI) and library-dependent (LD). For both types, the temporal and spatial stability of selected genotypes are aspects that need to be evaluated, and these aspects are often times missing when applying MST to environmental samples. LD-MST methods require the development of large databases comprised of source-specific isolates. Once a source-specific fingerprint has been identified, the temporal and spatial variability of that particular genotype still needs to be validated. LI-MST is based on the application of culture-independent methods such as amplification of DNA from environmental samples using 16S rDNA markers in combination with polymerase chain reaction (PCR).
Download or read book Indicators for Waterborne Pathogens written by National Research Council and published by National Academies Press. This book was released on 2004-06-19 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent and forecasted advances in microbiology, molecular biology, and analytical chemistry have made it timely to reassess the current paradigm of relying predominantly or exclusively on traditional bacterial indicators for all types of waterborne pathogens. Nonetheless, indicator approaches will still be required for the foreseeable future because it is not practical or feasible to monitor for the complete spectrum of microorganisms that may occur in water, and many known pathogens are difficult to detect directly and reliably in water samples. This comprehensive report recommends the development and use of a "tool box" approach by the U.S Environmental Protection Agency and others for assessing microbial water quality in which available indicator organisms (and/or pathogens in some cases) and detection method(s) are matched to the requirements of a particular application. The report further recommends the use of a phased, three-level monitoring framework to support the selection of indicators and indicator approaches.Â
Download or read book Fecal Bacteroidales Detection and Persistence of Viable Cells and Their DNA in the Aqueous Environment written by Sung Woo Bae and published by . This book was released on 2010 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technique for Detecting Sources of Human Pollution in Water Using an Enterococcus Biomarker written by Tracie Michelle Jenkins and published by . This book was released on 2005 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Waterborne Zoonoses written by World Health Organization and published by World Health Organization. This book was released on 2004 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zoonoses are infectious diseases that can be transmitted from animals (both wild and domestic) to humans. A significant number of emerging and re-emerging waterborne zoonotic pathogens have been recognised over recent decades, such as SARS, E. coli, campylobacter and cryptosporidium. This publication assesses current knowledge about waterborne zoonoses and identifies strategies and research needs for anticipating and controlling future emerging water-related diseases, in order to better protect the health of both humans and animals. It is based on the discussions of a workshop held in the United States in September 2003, which included 29 experts from 14 countries and diverse disciplines including microbiology, water epidemiology, medicine, sanitary engineering, food safety and regulatory policy.
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 Quantitative Microbial Source Tracking Using Bacteroidales as Fecal Source Identifier written by Dan Wang and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fecal pollution is a primary concern for recreational water bodies in US. The current water quality criteria are based on the cultivability of fecal indicator bacteria like E. coli and enterococci. These indicators are ubiquitous in the digestive tract of warm-blooded animals but are also known to persist and even multiply in the environment given favorable conditions. Hence their presence does not provide information on the sources of fecal contamination. In the past decade microbial source tracking (MST), the research area that uses host-specific microbes to identify the sources of fecal pollution, has undergone rapid development. A brief historical overview is provided in Chapter 1 and state-of-the art methods are presented and analyzed in Chapter 2. Quantitative PCR (qPCR)-based MST methods have been widely used for two reasons: they can detect both cultivable and uncultivable microbes and their process time is shorter comparing to other MST methods. The results from qPCR reactions need to be further processed to achieve quantitative MST because of analytical complications caused by the environmental water matrix. Two of the most important aspects will be addressed in Chapters 3 and 4. Chapter 3 attempts to solve the imperfect specificity and sensitivity of the qPCR assays with a statistical procedure that evaluates the impact of false positive/negative information. Chapter 4 addresses the inaccuracy in qPCR data analysis caused by the high noise signal and inconsistent amplification efficiency frequently seen in environmental water samples. Corrective measures are proposed to improve the accuracy of estimated DNA concentrations.
Download or read book Guidelines on recreational water quality Volume 1 written by World Health Organization and published by World Health Organization. This book was released on 2021-07-12 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Use of coastal, estuarine and freshwater recreational environments has significant benefits for health and well-being, including rest, relaxation, exercise, cultural and religious practices, and aesthetic pleasure, while also providing substantial local, regional and national economic benefits. These guidelines focus on water quality management for coastal and freshwater environments to protect public health. The guidelines: 1. describe the current state of knowledge about the possible adverse health impacts of various forms of water pollution; and2. set out recommendations for setting national health-based targets, conducting surveillance and risk assessments, putting in place systems to monitor and control risks, and providing timely advice to users on water safety.These guidelines are aimed at national and local authorities, and other entities with an obligation to exercise due diligence relating to the safety of recreational water sites. They may be implemented in conjunction with other measures for water safety (such as drowning prevention and sun exposure) and measures for environmental protection of recreational water use sites.
Download or read book Bacterial Genomes written by F.J. de Bruijn and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wide range of microbiologists, molecular biologists, and molecular evolutionary biologists will find this new volume of singular interest. It summarizes the present knowledge about the structure and stability of microbial genomes, and reviews the techniques used to analyze and fingerprint them. Maps of approximately thirty important microbes, along with articles on the construction and relevant features of the maps are included. The volume is not intended as a complete compendium of all information on microbial genomes, but rather focuses on approaches, methods and good examples of the analysis of small genomes.
Download or read book Quantitative Microbial Risk Assessment written by Charles N. Haas and published by John Wiley & Sons. This book was released on 2014-06-09 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides the latest QMRA methodologies to determine infection risk cause by either accidental microbial infections or deliberate infections caused by terrorism • Reviews the latest methodologies to quantify at every step of the microbial exposure pathways, from the first release of a pathogen to the actual human infection • Provides techniques on how to gather information, on how each microorganism moves through the environment, how to determine their survival rates on various media, and how people are exposed to the microorganism • Explains how QMRA can be used as a tool to measure the impact of interventions and identify the best policies and practices to protect public health and safety • Includes new information on genetic methods • Techniques use to develop risk models for drinking water, groundwater, recreational water, food and pathogens in the indoor environment
Download or read book Evaluation and Performance of Rapid Methods for Identifying and Tracking Sources of Fecal Pollution in Coastal Watersheds written by Vanessa Thulsiraj and published by . This book was released on 2014 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fecal contamination of coastal waters is known to degrade the environment and poses a health risk to recreational beach users. Fecal indicator bacteria (FIB) are used around the world to assess water quality and characterize fecal contamination. Elevated levels of FIB have been linked to health risks in epidemiological studies. However, some limitations exist with this indicator. FIB cannot be used to identify the specific sources as they originate from both human and animal sources. FIB may also persist and regrow in the environment. In order to effectively remediate the cause of pollution and characterize the hazards at chronically impaired beaches it is necessary to measure indicators that can provide information about the sources of the general fecal pollution. Tracking pollution sources at impaired beaches is critical to ensuring the health of coastal watersheds and reducing the incidence of swimming related illness. Molecular methods have gained popularity to identify and detect sources of fecal contamination using host-associated markers. The work presented here addresses areas warranting further research in the state of the science of water quality monitoring. In Chapter 2, we demonstrate that host-associated markers exhibit similar limits of detection in different water types and are robust in environmental field applications. Additionally, we provide a cost-benefit analysis and provide water quality managers with information supporting the inclusion of molecular methods in current monitoring practices. This body of work also presents novel methods for rapid and viability-based detection of recent fecal contamination with propidium monoazide (PMA-qPCR) and a field portable method covalently-linked IMS/ATP technique (Cov-IMS/ATP). In Chapters 3 and 4, we present results on optimization and specificity of the Cov-IMS/ATP. We evaluated the performance of Cov-IMS/ATP at three different watersheds for rapid quantification of enterococci, and show this method to be a robust tool in assessing water quality at complex sites. This work also addresses drawbacks of traditional qPCR to quantify viable fecal contamination. We validate the PMA-qPCR method and demonstrate its performance in detecting recent fecal contamination in environmental waters. Use of these methods demonstrates a new framework that can enhance current microbial source tracking studies and water quality monitoring.
Download or read book Strengthening Forensic Science in the United States written by National Research Council and published by National Academies Press. This book was released on 2009-07-29 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scores of talented and dedicated people serve the forensic science community, performing vitally important work. However, they are often constrained by lack of adequate resources, sound policies, and national support. It is clear that change and advancements, both systematic and scientific, are needed in a number of forensic science disciplines to ensure the reliability of work, establish enforceable standards, and promote best practices with consistent application. Strengthening Forensic Science in the United States: A Path Forward provides a detailed plan for addressing these needs and suggests the creation of a new government entity, the National Institute of Forensic Science, to establish and enforce standards within the forensic science community. The benefits of improving and regulating the forensic science disciplines are clear: assisting law enforcement officials, enhancing homeland security, and reducing the risk of wrongful conviction and exoneration. Strengthening Forensic Science in the United States gives a full account of what is needed to advance the forensic science disciplines, including upgrading of systems and organizational structures, better training, widespread adoption of uniform and enforceable best practices, and mandatory certification and accreditation programs. While this book provides an essential call-to-action for congress and policy makers, it also serves as a vital tool for law enforcement agencies, criminal prosecutors and attorneys, and forensic science educators.
Download or read book Survival and Persistence of Bacteroidales Human and Ruminant Specific Fecal Markers and Occurrence with Fecal Pathogens written by Sarah P. Walters and published by . This book was released on 2007 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aquatic fecal contamination from non-point sources impairs environmental health and serves as a vehicle for transmission of waterborne disease, resulting in economic losses worldwide. Accurate methods of diagnosing fecal pollution and its source are needed to prevent human exposure, remediate pollution, and reduce economic impacts. In order to obtain this goal, fecal indicator organisms should demonstrate persistence and survival profiles similar to fecal pathogens and be detected when pathogens are present. Molecular markers designed from Bacteroidales anaerobic fecal bacteria make good alternative indicator candidates because they identify fecal pollution sources and are not expected to grow in oxygenated environments. To further investigate the utility of these markers as indicators of fecal contamination and predictors of pathogen exposure, we evaluated co-occurrence of pathogenic E. coli O157:H7, Salmonella spp., and Campylobacter spp. with general, human, ruminant, and porcine-specific Bacteroidales molecular markers. We detected host-specific markers in samples where pathogens were present and found a significant correlation between presence of the ruminant markers and E. coli O157:H7, and the human markers and pathogenic Campylobacter spp. We examined growth and persistence of Bacteroidales organisms in aerobically incubated sewage influent using bromodeoxyuridine (BrdU) labeling and immunocapture. We identified growing Bacteroidales bacteria in BrdU-labeled DNA fractions after immunocapture with fluorescent fragment detection following a low, quantitative number of PCR cycles. We consistently detected growth of Bacteroidales organisms but were unable to detect growth of the human-specific Bacteroidales organisms using this method. We constructed microcosms to investigate how ambient light exposure affects survival and persistence of ruminant and human-specific Bacteroidales markers, relative to standard indicators. The ruminant-specific Bacteroidales markers displayed differential persistence and survival profiles in both light and dark incubations; this was not observed among the human-specific markers. In each microcosm, the standard indicators persisted and survived longer than any of the Bacteroidales host-specific markers. Host-specific Bacteroidales genetic markers show promise as an accurate, rapid, and reliable tool in health risk based analyses of fecal pollution. The molecular markers are detected when pathogens are present, persist less than 14 days in natural river water at 13°C, and the marker organisms do not proliferate in the environment.
