Location: Poultry Research
Project Number: 6064-13000-014-004-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jul 31, 2019
End Date: Jul 30, 2024
Objective:
1. Apply in ovo-based vaccine delivery technologies for the delivery of live attenuated APEC vaccines. (Subobjective 2c)
2. Development of novel techniques/strategies to control bacterial pathogens associated with poultry incubation and hatching.
Approach:
Obj. 1.
A protocol to incorporate a commercially available in ovo vaccinator for delivery of the Poulvac™ E. coli vaccine will be developed. An egg injection system from Zoetis/Pfizer Animal Health Global Poultry will be applied to the automated delivery of the vaccine. Trials will be run to determine the impact of the commercial system’s disinfection step. Lastly, hatchlings derived from in ovo vaccinated eggs should have Poulvac™ E. coli associated with most exterior portions of their bodies due to vaccine release inside the egg during development. The transmissibility of the Poulvac™ E. coli from the hatchlings derived from the commercially in ovo vaccinated eggs will be investigated. To develop and assess in ovo-based delivery methods for the live attenuated APEC vaccine (Poulvac™ E. coli), fertile eggs will be obtained from a commercial source and will be incubated as recommended by the supplier. Treatments will include multiple dosages. Prior to injection at 18 days, eggs will be screened for viability, live embryos will be injected according to treatment, and eggs will be transferred to hatching baskets. Following hatch, all treatment-associated chicks will be quantified to assess hatchability. Chicks will be swabbed to assess the presence of the Poulvac™ E. coli which will be performed utilizing a vaccine specific Taqman PCR assay. A subset of randomly (10%) selected hatchlings from each treatment will be reared through 3 weeks of age to assess of livability and humoral immune response. Mortality will be recorded daily, and all mortality will be necropsied and sampled for the presence of the Poulvac™ E. coli vaccine. At 3 weeks of age, all birds will be weighed, swabbed (choanal cleft, esophagus, and cloaca) to assess the presence of the Poulvac™ E. coli and bled (wing vein) for ELISA (IgY) assays to assess the humoral response.
Obj. 2.
Utilizing laboratory-based or benchtop studies, APEC strains of E. coli will be assessed for sensitivities to various antimicrobial agents for future application in hatchery sanitation/disinfection. Results will be applied to reducing bacterial pathogen load on fertile chicken eggs.
