Download or read book Molecular Mechanisms of Chemical Inactivation of Cryptosporidium Oocysts and Giardia Cysts written by Giovanni Widmer and published by American Water Works Association. This book was released on 2002 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report seeks to characterize, at the molecular level, the effect of water disinfectants on oocysts of Cryptosporidium parvum and on cysts of Giardia lamblia. It presents the results of ozone, chlorine, and ozone/chlorine sequential disinfection. Graphs, charts, and micrographs provide visual re
Download or read book Comparing Cell Culture and Mouse Assays for Measuring Infectivity of Cryptosporidium written by Paul A. Rochelle and published by IWA Publishing. This book was released on 2005-06-30 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cell culture techniques are routinely used for measuring the infectivity of a wide range of human pathogens. A variety of different cell culture systems and detection methodologies have been applied to Cryptosporidium parvum. However, the correlation between cell culture methods and animal infectivity assays has not been thoroughly investigated. Although many cell culture methods have been developed for C. parvum, it has not been proven that infectivity in cell culture is a good indicator of the ability of oocysts to cause infections in animals. The objective of this research was to compare in-vitro cell culture methods with a mouse assay for measuring infectivity of C. parvum oocysts. The specific objectives were to (1) compare the dose response and sensitivity of cell culture and mouse assays with multiple isolates; (2) compare infectivity methods with oocysts exposed to environmental water samples; (3) determine the reproducibility and variability of the methods; and (4) compare cell culture and animal assays for assessing ozone and UV disinfection.For untreated oocysts, challenge doses were enumerated by flow cytometry. Dose response curves were constructed by regression analysis of oocyst dose against a logistic transformation of the proportional infectivity and the 50% infectious doses for each isolate were calculated by solving the regression for a logit value of zero. Infections in CD-1 mice were detected by microscopy following staining with hematoxylin and eosin. Infection in HCT-8 and Caco-2 cells was detected by C. parvum-specific RT-PCR. In MDCK cells, infection was detected using immunofluorescence. For disinfection studies, oocysts were exposed to UV using a medium-pressure, collimated beam apparatus and inactivation was measured as the difference in ID50 of unexposed and UV-exposed oocysts. Oocysts were exposed to ozone using batch, semi-batch, and single continuously stirred tank reactors at 1, 5, and 15°C.This investigation demonstrated that in-vitro cell culture was equivalent with a mouse assay for measuring infectivity of untreated C. parvum oocysts and should therefore be considered a practical alternative for assessing the potential of oocysts to cause infection. However, the high levels of variability displayed by mouse and cell culture methods indicated that infectivity and disinfection experiments should be limited to discerning relatively large differences. Of the three cell culture assays, the HCT-8/RT-PCR method displayed the closest agreement with the CD-1 mouse assay. C. hominis was infectious in HCT-8 cells but did not infect mice. Similar results were obtained with CD-1 mice and HCT-8 cells for measuring infectivity of oocysts that had been exposed to environmental water for 35 days. There was also very good agreement between HCT-8 cell culture and CD-1 mouse assays for measuring UV inactivation of C. parvum. A medium-pressure UV dosage of 5.6 mJ/cm2 resulted in 2-log10 inactivation. The shapes of ozone inactivation curves were generally the same for mouse and cell culture derived data although the CD-1 mouse assay typically generated 0.5 to 1-log10 higher levels of inactivation than HCT-8 cells. In addition, there was a stimulatory response in oocysts exposed to ozone below 20 mg.min/L when assayed by HCT-8 cell culture. Consequently, further research is necessary to understand the response of oocysts to ozone when inactivation is assessed by cell culture methods. The water industry should adopt in-vitro cell culture as a routine method for measuring the infectivity of waterborne C. parvum and C. hominis oocysts. This project has demonstrated that cell culture has equivalency with the standard CD-1 mouse assay and cell culture assays can be applied to oocysts recovered from water using approved methods. However, there needs to be a thorough, robust, and well-controlled study to compare the various cell culture-based assays for measuring C. parvum and C. hominis infectivity. This evaluation should include inter-laboratory comparisons and round-robin testing. Cell culture-based assays should also be used to assess disinfection of C. hominis isolates. Originally published by AwwaRF for its subscribers in 2004. This publication can also be purchased and downloaded via Pay Per View on Water Intelligence Online - click on the Pay Per View icon below
Download or read book Photochemical Purification of Water and Air written by Thomas Oppenländer and published by John Wiley & Sons. This book was released on 2003-02-03 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: While the treatment of water and exhaust gas using ultraviolet (UV) light offers both ecological and economic advantages, information on photo-initiated advanced oxidation technologies (AOTs) has been dispersed among various journals and proceedings until now. This authoritative and comprehensive handbook is the first to cover both the photochemical fundamentals and practical applications, including a description of advanced oxidation processes (AOPs) and process engineering of suitable photoreactors. The author presents various real-world examples, including economic aspects, while many references to current scientific literature facilitate access to current research topics relevant for water and air industries. Throughout, over 140 detailed figures visualize photochemical and photophysical phenomena, and help in interpreting important research results. From the foreword by James R. Bolton (President of Bolton Photosciences Inc., Executive Director of the International Ultraviolet Association (IUVA)): "Prof. Oppenländer is well qualified to write about the AOPs/AOTs, since he has contributed to this literature in a very significant manner. This book will be of considerable value to graduate students, science and engineering faculty, scientists, process engineers and sales engineers in industry, government regulators and health professionals."
Download or read book Cryptosporidium written by Jan R. Mead and published by Humana. This book was released on 2019-08-27 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book encompasses broad aspects of Cryptosporidium research with established methods that have been improved and expanded over the years as well as recent cutting-edge techniques. Within this collection are numerous molecular methods as well as protocols for genotyping and diagnostics, while also including room for in vitro cell culture techniques to address the issues with growing this difficult organism continuously. Written for the highly successful Methods in Molecular Biology series, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Cryptosporidium: Methods and Protocols serves as an idea guide to the inherent challenges of working with cryptosporidial parasites to provide a foundation for new investigators to build upon. The chapter “Accessing Cryptosporidium Omic and Isolate Data via CryptoDB.org” is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.
Download or read book Twort s Water Supply written by Malcolm J. Brandt and published by Butterworth-Heinemann. This book was released on 2016-09-03 with total page 968 pages. Available in PDF, EPUB and Kindle. Book excerpt: Twort's Water Supply, Seventh Edition, has been expanded to provide the latest tools and techniques to meet engineering challenges over dwindling natural resources. Approximately 1.1 billion people in rural and peri-urban communities of developing countries do not have access to safe drinking water. The mortality from diarrhea-related diseases amounts to 2.2 million people each year from the consumption of unsafe water. This update reflects the latest WHO, European, UK, and US standards, including the European Water Framework Directive. The book also includes an expansion of waste and sludge disposal, including energy and sustainability, and new chapters on intakes, chemical storage, handling, and sampling. Written for both professionals and students, this book is essential reading for anyone working in water engineering. Features expanded coverage of waste and sludge disposal to include energy use and sustainability Includes a new chapter on intakes Includes a new chapter on chemical storage and handling
Download or read book American Book Publishing Record written by and published by . This book was released on 2003 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water Treatment and Pathogen Control written by LeChevallier M.W. and published by World Health Organization. This book was released on 2004-09-24 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation This publication provides a critical analysis of the literature on removal and inactivation of pathogenic microbes in water to aid the water quality specialist and design engineer in making decisions regarding microbial water quality.
Download or read book Wastewater Pathogens written by Michael H. Gerardi and published by John Wiley & Sons. This book was released on 2004-10-28 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: A practical guide to wastewater pathogens The fourth volume in Wiley's Wastewater Microbiology series, Wastewater Pathogens offers wastewater personnel a practical guide that is free of overly technical jargon. Designed especially for operators, the text provides straight facts on the biology of treatment as well as appropriate protective measures. Coverage includes: * An overview of relevant history, hazards, and organisms * Viruses, bacteria, and fungi * Protozoa and helminthes * Ectoparasites and rodents * Aerosols, foam, and sludge * Disease transmission and the body's defenses * Removal, inactivation, and destruction of pathogens * Hygiene measures, protective equipment, and immunizations
Download or read book Guidelines for Drinking water Quality written by World Health Organization and published by World Health Organization. This book was released on 1993 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume describes the methods used in the surveillance of drinking water quality in the light of the special problems of small-community supplies, particularly in developing countries, and outlines the strategies necessary to ensure that surveillance is effective.
Download or read book Book Review Index written by and published by . This book was released on 2004 with total page 1320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Every 3rd issue is a quarterly cumulation.
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 Onsite Wastewater Treatment Systems Manual written by and published by . This book was released on 2002 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This manual contains overview information on treatment technologies, installation practices, and past performance."--Introduction.
Download or read book Foodborne Parasites written by Ynes R. Ortega and published by Springer Science & Business Media. This book was released on 2006-11-22 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines the two major parasite groups that are transmitted via water or foods: the single-celled protozoa, and the helminths: cestodes (tapeworms), nematodes (round worms), and trematodes (flukes). Each chapter covers the biology, mechanisms of pathogenesis, epidemiology, treatment, and inactivation of these parasites. This important new text offers a better understanding of the biology and control of parasitic infections necessary to reduce or eliminate future outbreaks in the U.S. and elsewhere.
Download or read book Forthcoming Books written by Rose Arny and published by . This book was released on 2003 with total page 1816 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Foodborne Pathogens written by Clive de W. Blackburn and published by McGraw Hill Professional. This book was released on 2002 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: As trends in foodborne disease continue to rise, the effective identification and control of pathogens becomes ever more important for the food industry. With its distinguished international team of contributors, Foodborne pathogens provides an authoritative and practical guide to effective control measures and how they can be applied in practice to individual pathogens. Part One looks at general techniques in assessing and managing microbiological hazards. After a review of analytical methods, there are chapters on modelling pathogen behaviour and carrying out a risk assessment as the essential foundation for effective food safety management. The following chapters then look at good management practice in key stages in the supply chain, starting with farm production. There are chapters on hygienic plant design and sanitation, and safe process design and operation which provide the foundation for a discussion of what makes for effective HACCP systems implementation. There is also a chapter on safe practices for consumers and food handlers in the retail and catering sectors.This discussion of pathogen control then provides a context for Part Two which looks at what this means in practice for key pathogens such as E. coli, Salmonella, Listeria and Campylobacter. Each chapter discusses pathogen characteristics, detection methods and control procedures. Part Three then looks at non-bacterial hazards such as viruses and parasites, as well as emerging potential 'hazards' such as Mycobacterium paratuberculosis and the increasingly important area of chronic disease. Foodborne pathogens will be widely welcomed as an essential and authoritative guide to successful pathogen control in the food industry.
Download or read book Optimizing Water Treatment Plant Performance Using the Composite Correction Program written by and published by . This book was released on 1998 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photochemical Reactors written by Ernest R. Blatchley, III and published by John Wiley & Sons. This book was released on 2022-11-01 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: An intuitively organized and incisive exploration of UV radiation and its modern applications In Photochemical Reactors: Theory, Methods, and Applications of Ultraviolet Radiation, distinguished civil engineer and researcher Dr. Ernest R. Blatchley III delivers a comprehensive exploration of the theory, methods, and contemporary and emerging applications of ultraviolet (UV) radiation. The author describes the fundamentals of the history of photochemistry and photochemical reactions before moving on to consider the dynamic behavior of UV-based reactor systems and the physical concepts that govern natural and man-made sources of UV radiation. The book also covers the numerical and empirical methods used to evaluate photochemical kinetics, photobiological kinetics, and the dynamics of UV photoreactors. Common and emerging applications of UV radiation—like the disinfection of water, wastewater, air, and surfaces—are discussed, and UV-induced transformation processes are also explored. Readers will also find: Thorough introductions to methods and principles that are universal to UV processes, as well as comparisons between those processes Critical explorations of the physics of natural and artificial sources of ultraviolet radiation Practical discussions of modern applications of UV radiation, including the disinfection of water, air, wastewater, and surfaces, as well as the use of UV photoreactors to promote photolysis and photo-initiated, radical-mediated reactions Perfect for UV professionals, academics, and scientists, Photochemical Reactors: Theory, Methods, and Applications of Ultraviolet Radiation will also earn a place in the libraries of professionals working in companies that manufacture UV reactors, as well as engineering consultants with a professional interest in ultraviolet radiation.