Investigation of Methods to Improve Sustainable Health in Poultry

Non-Technical Summary:<br/>
Increasing regulations on the use of chemicals and antibiotics in food animals has spurred research in the area of sustainable health. Without the discovery and application of sustainable alternatives for the rearing of healthy poultry flocks, production levels will decrease. Methods for combating disease and improving performance in this project include prebiotics and probiotics, bacteriphages, and vaccines to help alleviate the need for antibiotics and other chemicals in poultry production. Targeted diseases include Salmonella, Campylobacter, Clostridium, Coccidia, Bordetella, and avian influenza. Probiotics, beneficial bacteria, will be investigated for both growth enhancing benefits and control of disease. They will be selected based on a multitude of properties including enzyme production, breakdown of non-digestable nutrients, and activity against pathogens. Bacteriophage studies will be targeted towards control of foodborne pathogens for both ante- and post mortem applications. Recombinant vaccines designed for expression of antigens in a GRAS bacteria will be tested for ability to elicit an immune response and protect against diseases of concern to the poultry industry. In addition to the vectored vaccine platform, killed bacterin vaccines will be investigated for their ability to provide protection against diseases of immediate concern to poultry producers. This method of production can provide an autogenous vaccine, or vaccine against diseases for which large scale production is not required (such as Bordetella for turkeys). Novel adjuvants, or modifications to existing adjuvants, will be tested for their ability to enhance an immune response to vaccines developed in this laboratory. Adjuvants of target are those that are GRAS and acceptable for oral consumption by poultry. Taken together, the multi-legged approach to developing methods aimed at decreasing the dependence of the poultry industry on antibiotics and chemical additives will increase the long-term sustainability and health of poultry, thus keeping poultry products at an affordable price for consumers.
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Approach:<br/>
Prebiotics and Probiotics - bacteria and prebiotic nutrients will be selected via in vitro methods to isolate those with desired effects. These properties may include the reduction of pathogens in crop and direct competition assay, production of bacterocins, metabolization of prebiotic nutrients, enzyme production, stability, and heat resistance. Once desired prebiotics and probiotics have passed in vitro testing, they will be evaluated in vivo for effects on pathogen recovery and performance in broilers and turkeys. <br/>Bacteriophages - viruses that lyse bacteria can easily be isolated from sources containing high amounts of microbiota. These sources include wastewater, groundwater, soil, and used animal bedding. The desired bacteriophages are amplified by co-incubation with the target pathogen, and then pour-plated onto agar plates. Those viruses showing promise by efficiently lysing the target bacteria will be further tested against the pathogens. Testing may include administration to poultry for ante mortem control of pathogens, or application onto processed poultry to decrease the risk of foodborne illness. <br/>Vaccines - Recombinant platform - Antigen sequences will be inserted into a plasmid for expression by a Bacillus subtilis vector. Antigenic sequences are selected based on a number of characteristics including cell surface expression, potential immune reaction, and conservation among multiple species. Targeted diseases/pathogens include, but are not limited to: Salmonella, Campylobacter, avian influenza, Coccidiosis, and Clostridium. Included in the vaccine constructs will be immune-potentiators designed and selected for their ability to stimulate both an innate and acquired immune response from the animal. Each vaccine will be tested for expression of the desired components following trials to evaluate both immune response and protection in poultry. <br/>Killed bacterin vaccines - This aspect of the project will investigate the potential of killed whole-cell vaccines to provide protection against a multitude of diseases concerning the poultry industry. These vaccines can be either for general consumption, or autogenous vaccines against a specific pathogen of concern for a select group of flocks. Production of killed bacterin vaccines includes growing pure cultures of the desired pathogen, followed by methods to kill the target. Killing can be completed by heat or chemicals safe for application to poultry. These killed bacterin vaccines will often be combined with an adjuvant under development, described below. <br/>Adjuvants - Adjuvants will be tested for their ability to enhance the immune response to vaccines. Multiple formulations will be combined with vaccines and administered by multiple methods to test their effects. Those adjuvants that are acceptable for both injection and oral consumption by poultry are the most desired.
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Progress:<br/>
2012/01 TO 2012/12<br/>
OUTPUTS: During 2012, work continued on several probiotic and direct fed microbial technologies which have been developed or co-developed by our laboratory and licensed to commercial interest by the UA Division of Agriculture. Research in our laboratories, and those of our collaborators, has shown that these products, now commercially available, can markedly improve production performance, health and well being, while reducing antemortem Salmonella levels in live poultry. This research has led to several recent additional patent filings and commercialization efforts, resulting in creation of a startup company in NW Arkansas which now employees 32 scientists and production personnel. Ongoing research is aimed at improved efficacy through enhanced enteric colonization, endogenous digestive enzyme production, and improved efficacy against selected disease-causing agents. Other alternative methodologies are aimed at developing new recombinant vaccine technologies with broad efficacy against a wide range of enteric and respiratory pathogens and strong preliminary efficacy against selected disease-causing agents has been published, in collaboration with Dr. Kwon (Poultry Science) and colleagues at other institutions. This patent-pending technology has been licensed by the UA Division of Agriculture to an international company, with sublicenses to two major US-based biologics companies. Ongoing investigations with regard to a novel adjuvant, capable of inducing an oral-delivered immune response using inactivated (killed) vaccines is encouraging, and a US patent application was recently licensed by a major biologics company. In 2012, 26 US and international patent actions were filed through the UA Division of Agriculture with regard to the above-mentioned activities. PARTICIPANTS: B.M. Hargis G.I. Tellez N.R. Pumford L.R. Bielke O.F. Faulkner TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
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Impact:<br/> Commercialized probiotics and direct-fed microbial acceptance by the U.S. and international poultry industries is very rapidly growing, with the startup company, initiated through Division of Agriculture-licensed technology, profitable for the last three years, and supporting 32 full-time scientists, technicians and personnel in Arkansas. A separate startup company, with an international partner, has licensed the recombinant vaccine technology with sublicensed technology to two major US-based biologics companies. Novel and patent-pending adjuvant technology has proven useful for a number of Arkansas-based poultry companies for combination with inactivated agents (autogenous vaccines) for which no commercially-available vaccines currently exist.