Progress 06/01/14 to 01/31/18
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Respiratory diseaserepresents a loss of >$500 million/year to the domestic cattleindustry due totreatment costs, poor weight gain, reduced carcass value and death. Mannheimia haemolytica bacteria causes the most serious form of pneumonia, followed by Pasteurella multocida bacteria and others. Various approaches to mitigate this loss are employed,including prevention viaadministrationoflow levels of antibiotics in "medicated feeds", thispractice now tightly regulated or forbidden by the Food and Drug Administration (FDA) via its Veterinary Feed Directive (VFD) Regulation of 2015due to public and industry concerns overbuilding antibioticresistance both in animals and in humans. Another much more desirable means of prevention is vaccination. Currentanimal vaccine technology developed over the past 40 years has not appreciably reducedrespiratory disease losses in cattle. Use and overuse of antibiotics to treat thisdisease has severalserious drawbacks to not onlythe cattle industry itself, includinghigh drug costs andreduced animal value, but also to humans by encouraging the evolutionofmulti-drug resistant bacteria. Effective next-generation vaccines against the most common organisms causing bovine respiratory disease is a logical approach to help reduce antibiotic use in cattle. SolidTech is working toward USDA licensure ofan innovative, yet economical, vaccine the help prevent M. haemolytica infections in cattle andperhaps utilizing the same technology to help prevent infection by another closely-related bacteria, P.multocida. Success of this project and commercialization of an effective vaccine against bacterial respiratory infections can greatly improve production of high-quality, reasonably priced beef to help feed people locally and abroadand also clearly helps satisfy the public interest by addressingUSDA Strategic Goal 1, "to Assist Rural Communities to Create Prosperity" and Goal 3, to Help America Promote Agricultural Production and Biotechnology Exports as America Works to Increase Food Security". Since Phase I funding began and beforeobtaining approval for the first of 3No-Cost Extensions of Time byNIFA, SolidTech focused on itsoriginal goal of developing a candidate"Outer Membrane Vesicle" (OMV) vaccine against the single targetbacterial pathogen,Mannheimia haemolytica. Upon successful completion of Objective 1, SolidTechexpanded itsfocus to include a secondimportant cattlerespiratorypathogen,Pasteurella multocida. Both M. haemolytica andP. multocidabacteriasecrete OMV's, the target componentof this vaccine. SolidTech laterdiscovered both organisms couldbepropagated in the same animal origin ingredient freemedia. Lastly,because several currentcommercial M. haemolyticavaccines also include aP. multocidacomponent, it was decided that before submitting aLicense Application and Outline of Production to the USDA for the combination product, production methods forP. multocidamustbe established so the dual componentvaccinecould be developed and commercialized. Objective 1: The first step includedscreening multipleM. haemolytica field isolates for a single high OMV-yielding strain. Once a candidate strainwas selected, it was analyzed by the Oklahoma Animal Disease Diagnostic Laboratory (OADDL) and Oklahoma State University (OSU). The laboratories determined the field strain to include both the target isolate and a spontaneous mutant (Ayalew S, Confer AW, Hansen RD, Couger MB. 2017. Genomic sequence of a spontaneous nonhemolytic mutant ofMannheimia haemolytica16041065 GH. Genome Announc 5:e01720-16. https://doi.org/10.1128/genomeA.01720-16. NIFA Support Acknowledged). The selected strain was purified and frozenMaster and Working (manufacturing) Seeds established and tested for purity. SolidTech evaluated numerous growth media to propagate the organism for manufacturing and successfully identified one that contained NO ingredients of animal origin, unlike some (all?) current commercial products. Scale-up to a high-tech fermenter wasestablished. An acceptableP. multocidafield strain has beenidentified and a Master Seed created. Preliminary testing shows this strain grows similarly in SolidTech'sanimal originingredient free medium to be used to propagateM. haemolytica.Identity and purity testing is currently being conducted. A production Working Seed will be established pending satisfactory Master Seed identity and purity testing. Objective 2: AnOutline of Production has been drafted for the manufacture of theM. haemolyticavaccine. Once manufacturing parameters are established forP. multocida, criteria will be inserted in the Outline, thenboth the Outline of Production for the combination product andLicense Application(s) will be submitted to the USDA-CVB. Objective 3: PrototypeM. haemolyticavaccine candidateswere prepared, incorporating multiple adjuvants (immune stimulants) and three (3) serologic (antibody)studies conducted at OSU (Stillwater, OK). The third study, completed during 4Q2017, suggested an appropriateformulationfor preparingcandidate cattle vaccines. A solid dosage controlled release delivery system was tested, but proved the mouse not to be an acceptable model for evaluating such a system. SUMMARY Despite advances in the understanding of bovine respiratory disease and improvements invaccine technology, diseaseincidence has not changed significantly. Newer strategies are required fordeveloping next-generation vaccines for the prevention and control of respiratory disease in cattle caused by two (2)of the most incriminatedbacteria, Mannheimia haemolyticaandPasteurella multocida. Outer Membrane Vesicles (OMV's) are secreted from the surface of many disease-causing bacteria and are believed to help establish the infection/disease in humans and other non-human mammals. Theinclusion of OMV's and other bacterial surface components in a vaccine therefore makes sense when developing a vaccine so the immune system can develop a protective response against therelevant bacterial "part(s)" and not against all the "junk". In fact, inclusion of the wrong or too many irrelevantbacterial fragments or secretions (e.g. pyrogens)can cause both lumps and bumps at the injection site and accompanying edible tissue (meat) or even cause an allergic reaction ormake the animal MORE susceptible to the disease you are trying to prevent. Newer generation expensive human vaccines are being develped based on OMVtechnology, but veterinary vaccines, especially those intended for food producing animals, must also be much less expensive. Therefore, most current veterinary vaccines incorporate the entire bacterial cell and not targeted components, since purification can add significant manufacturingexpense. The newVeterinary Feed Directives (VFD's) instituted by the FDA nowlimit the use of antibiotics for the prevention of and even treatment of food producing animals. Antibiotic salvage treatments can be very expensive. Therefore, cattle producers and veterinarians are becomingmore tolerant of increased product cost, IF thevaccineis shownto be more effective atpreventing disease. SolidTech's manufacturing methods utilizeless expensive ingredientsand require NOin-house or contracted USDA animal origin ingredienttesting sinceonlynon-animal origin ingredient components are used to grow the bacteria. Chemical-free inactivation methods and cost-effective down-stream processing proceduresshould permit the development and commercialization of reasonably priced, higher technology vaccines for food producing animals.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2017
Citation:
Ayalew S, Confer AW, Hansen RD, Couger MB. 2017. Genome sequence of a spontaneous nonhemolytic mutant of Mannheimia haemolytica 16041065 GH. Genome Announc 5:e01720-16. https://doi.org/10.1128/genomeA.01720-16.
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