Evaluation of Genotyping Techniques for Crytosporidium Parvum


Book Description

A research teams reports on its efforts to develop and implement DNA fingerprinting techniques to characterize and differentiate the parvus species of protozoal parasite that is ubiquitous in rivers and lakes, is relatively resistant to chlorine disinfection at commonly used concentrations, and can prove fatal for immune compromised people who become infected. They evaluate fingerprinting methods based on polymerase chain reaction, determine which method is most suitable for determining strains or isolates within a species, implement the most appropriate molecular method for determining whether the isolates can be differentiated based on its animal or human host or geographical source, and determine the particular source of the protozoa contamination in source water. The report is not indexed. c. Book News Inc.




Cryptosporidium


Book Description

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.




Cryptosporidium and Cryptosporidiosis


Book Description

From the microscopic observation of infection to the widespread application of molecular techniques in taxonomy and epidemiology, to the genome sequencing of two major species and advances in biochemistry, phylogeny, and water treatment, new information on this fascinating genus continues to mount as we discover and utilize the latest scientific te




Giardia and Cryptosporidium


Book Description

Giardia and Cryptosporidium are both parasites of considerable global interest due to the gastrointestinal problems these organisms can cause in humans as well as domestic and wild animals. Despite its long history as the causative agent of giardiasis, the clinical and zoonotic significance of Giardia infections in humans and animals is only beginning to emerge with the application of molecular tools. Less is known about Cryptosporidium and studies seek to understand the impact of infection in livestock and other animals, its epidemiology and zoonotic significance. Presenting a comprehensive overview of recent research this book draws on the experience of experts in all fields of Giardia and Cryptosporidium research.




Veterinary PCR Diagnostics


Book Description

"PCR (Polymerase Chain Reaction) technology has become an indispensable component of routine veterinary diagnostics. However, a number of pitfalls and limiting factors affect its sensitivity and specificity of detection. It is imperative that veterinary "




Manual of Security Sensitive Microbes and Toxins


Book Description

Security sensitive microbes (viruses, bacteria, fungi, and parasites) and toxins, which are often referred to as the select agents and toxins, have the capacity to cause serious illness and death in humans, animals, and plants. Throughout history, these microbes and toxins have been exploited in one form or another as biowarfare and bioterror agents that create fear and panic well beyond any actual physical damages they might cause. Manual of Security Sensitive Microbes and Toxins provides comprehensive, state-of-the-art coverage of microbes and toxins of biosecurity concern. The ultimate goal is to increase our awareness of these agents and enhance our preparedness against any future bio-emergencies. The book begins with an introduction containing a brief overview of the historical aspects of security sensitive microbes and toxins. This is followed by a concise summary of the current status in relation to the regulation of security sensitive microbes and toxins and a discussion of future development trends. The book is divided into seven parts: Microbes and Toxins Affecting Humans and Animals: Viruses Microbes and Toxins Affecting Human and Animals: Bacteria Microbes and Toxins Affecting Human and Animals: Fungus and Parasite Microbes and Toxins Affecting Human and Animals: Toxins Microbes Affecting Animals: Viruses Microbes Affecting Animals: Bacteria Microbes Affecting Plants Written by experts in the relevant areas of research, the chapters are authoritative reviews, each one covering a single microbe or toxin with respect to its classification, biology, epidemiology, pathogenesis, identification, diagnosis, treatment, and prevention. The chapters also discuss the limitations of our current knowledge and challenges relating to improved detection and control of the microbe or toxin.







Foodborne Parasites


Book Description

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.




Cryptosporidiosis and Microsporidiosis


Book Description

'... This volume provides most complete and balanced coverage of essential aspects of the pathogens as well as the diagnosis and clinical correlations of the disease they cause. It is set to become a valuable refrence for parasitologists, protozoologists, molecular biologists, clinical mecrobiologists, epidemiologists and specialists in infectious diseases.'




Comparing Cell Culture and Mouse Assays for Measuring Infectivity of Cryptosporidium


Book Description

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