Enteric Diseases of Swine and Cattle: Prevention, Control and Food Safety

NON-TECHNICAL SUMMARY: This project will define mechanisms of pathogen-host-environmental interactions in enteric and food borne diseases, develop and improve diagnostics, treatment, and preventative measures for enteric and food borne diseases and provide training and continuing education opportunities and dissemination of information to students, producers, veterinarians and diagnostic laboratories. <P>
APPROACH: The collaborative approach of the Illinois Station on this multi-state NC project is described below for each objective of the project. <P>Objective 1: In collaboration with IL, OH will identify and characterize the ABOH histo-blood type antigens on porcine and bovine tissues and assess different calicivirus VLP genotypes for binding to these ABOH types, comparing various NoV strains including human NoVs to predict or confirm the potential for interspecies transmission. OH, AZ and IL will survey shellfish, environmental water sources or unprocessed foods for potential foodborne enteric pathogens and use sequence analysis to infer their host species origin. <P>Objective 2: IL and OH will collaborate to test the therapeutic efficacy of a novel synthetic neoglycolipid receptor analogue (SLPE) developed by IL in protecting against various strains of porcine rotavirus. OH will provide a variety of porcine and bovine rotavirus strains and rotavirus-like particles (VLP) with known P and G types to define the receptor specificity and for potential vaccine applications. They will determine the in vivo delivery parameters (dosage, time, frequency of administration, delivery vehicle, intestinal survival, transport, and absorption kinetics) necessary for optimal therapeutic efficacy of SLPE, as well as activity against different field strains of porcine rotavirus. IL will also continue to pursue possible synergistic therapeutic effects of SLPE in combination with milk/colostrum oligosaccharides and dietary isoflavones. IL also will continue its work on defining the kinetics of overland transport and fate of rotavirus and Cryptosporidium under different environmental conditions including the use of vegetative filter strips to reduce or eliminate virus contamination of agricultural watersheds. IL will continue its work defining the mechanism of Cryptosporidium parvum sporozoite invasion of host cells using two approaches: 1) Identify naturally occurring molecule(s) that mediate sporozoite recognition or invasion; and 2) Defining the cellular and molecular mechanisms by which one such molecule, LCUFA, blocks sporozoite-host cell invasion. IL will investigate the use of LCUFA as a dietary therapeutic agent for treatment of cryptosporidiosis using whole animal and intestinal xenograft animal models. IL is also evaluating the impact of dietary distillers dried grains with solubles (DDGS) on young pigs experimentally infected with Escherichia coli and on young chicks challenged with the coccidial parasite species, Eimeria acervulina. <P>Objective 3: In order to educate the public, animal care professionals, students and fellow scientists, this multi-state committee and its cooperating Experiment Stations will provide: 1) Training to college undergraduate and graduate students; 2) Information to livestock producers and/or professionals; 3) Knowledge and continuing education to station representatives and collaborating scientists; and 4) A forum for scientific exchange among colleagues of the international scientific community, and dissemination of knowledge to the biologics industry.
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PROGRESS: 2007/01 TO 2007/12 <br>
1. Development of novel methods for detection of waterborne pathogens (Cryptosporidium and rotavirus). We have begun collaborative studies to develop new technology, in collaboration with Dr. Brian Cunningham (University of Illinois Department of Electrical and Computing Engineering) for the sensitive detection of environmental microbial pathogens using label-free photonic crystal biosensor technology. Using this new sensor technology, we have demonstrated that porcine rotavirus can be specifically detected in aqueous samples as sensitively as conventional ELISA but without the need for secondary label processing.<br> 2. Focus on effective interventions - Develop and improve interventions and preventative measures to reduce the incidence and prevalence of infections of cattle and swine with enteric and food borne disease agents. A. Porcine Group A Rotavirus - Receptor Therapeutic Approaches for Porcine Rotavirus Disease We have synthesized a sialyl-lactosylphosphatidylethanolamine (SLPE) neoglycolipid that displays a potent ability to inhibit both virus binding and infectivity in vitro. In field trials this inhibitor blocked infection, virus shedding and diarrhea using a twice a day dosage administered to newborn pigs at the time of virus inoculation. We are also investigating, in collaborative studies with Dr. Sharon Donovan, Department of Food Science and Human Nutrition, the synergistic effect of SLPE and specific porcine and human milk oligosaccharides, as well as soybean derived flavonoids, which exhibit anti-rotavirus activity. B. Cryptosporidium parvum - Using a cell-suspension sporozoite adhesion assay we have purified a lipid fraction that inhibits sporozoite-host cell invasion. Preliminary data suggest this lipid is inhibiting sporozoite microneme secretion and gliding motility. Suppressive subtractive hybridization experiments aimed at identifying specific sporozoite genes expressed in response to host cell attachment or exposure to the inhibitory lipid indicate these processes occur without the necessity for attachment- or lipid-induced differential gene expression. C. Control of Microbial Contamination of Agriculture Watersheds - We have determined the cryptosporidium oocysts are effectively retarded from overland transport by vegetative filter strips (VFS) and that the mechanism of this retardation is specific adhesion to the clay particles of the soil that occurs as a consequence of reduced flow over a vegetated surface as compared to bare soil. These results have allowed us to leverage NC-1007 support to submit and receive a new USDA NRI grant 2006-35102-17344, CONTROL OF CRYPTOSPORIDIUM AND ROTAVIRUS CONTAMINATION IN AGRICULTURAL WATERSHEDS, PI: Kuhlenschmidt, M.S., Co-PI: Kalita, P., $400,000.00, 8/1/06 - 7/31/09, as well as a new submission to NSF entitled: Transport mechanism of Cryptosporidium parvum oocysts in overland and near-surface environment: A combined study of experiments and modeling, PI: Nguyen, T.H.; Co-PIs: Prasanta K. Kalita and Mark S. Kuhlenschmidt, $472,000.00.<P>
IMPACT: 2007/01 TO 2007/12
<br>Group A rotaviruses are among the most important agents associated with severe diarrhea in the young of both animals and people. They are of prime agricultural importance since they cause serious neonatal diarrhea of many animal species, most importantly neonatal and post-weaning pigs and calves. Extensive efforts to produce a deliverable commercial vaccine, including the use of reassortants, attenuated live strains and vector expression of viral capsid proteins have yet to be successful. Furthermore, despite the likelihood that efficacious rotavirus vaccines for humans will be available in the near future, it is not certain these vaccines will be available or deliverable to many of the people in developing countries who are most affected by the disease. Accordingly, the prophylaxis or treatment of rotavirus diarrheal disease by nutritional intervention, through the use of easily deliverable nutriceuticals, is potentially of great significance for the control of this disease in both agricultural and human medicine arenas. Cryptosporidium parvum causes a debilitating diarrhea of livestock either alone or in concert with other enteropathogens. This agricultural problem is compounded by the public health concern of contamination of municipal water supplies by domestic and wild animal feces such as occurred in Milwaukee. In addition, cryptosporidiosis is part of the AIDS related disease complex. Despite decades of research in a variety of animal models and utilizing varied technologies, effective prophylaxis or therapeutics for C. parvum infection or disease are not available. Our approach to the control of enteric diseases of livestock has been non-traditional in the sense that it is not aimed towards vaccine production or immune regulation. Instead, we reason that if we develop assay systems that are biologically relevant and can precisely reproduce, in vitro, the interactions between the infectious agent and the host cell, then we can use these assays to identify natural products (e.g. the inhibitory lipid above) or synthetic derivatives that interfere with parasite-host cell interactions required for infection. Such molecules, particularly natural products, could be utilized as nutriceutical feed additives to inactivate parasites and thus prevent or reduce parasite load and limit the severity of disease. Such an approach could benefit not only animal health but would reduce the likelihood of zoonotic spread of Cryptosporidium parvum through contamination of the water supply from domestic livestock operations.