An in ovo vaccine that targets multiple bacteria species in one dose reduced lameness caused by a top economic and animal welfare issue for the broiler industry, bacterial chondronecrosis with osteomyelitis (BCO).
“We’re creating something that will help control or reduce lameness,” Adnan Alrubaye, assistant professor and associate director of the graduate program in cell and molecular biology, conducts research for the University of Arkansas System Division of Agriculture through its research arm, the Arkansas Agricultural Experiment Station, said.
BCO occurs when damage to the poultry gut results in bacteria traveling through the gut barrier into the leg bones of a chicken, causing lesions and lameness. BCO symptoms typically appear between 30 and 40 days of age, but birds become predisposed to the disease before they hatch.
“Part of the issue is that broilers don’t get this lameness until the later stages of development,” added Alrubaye.
There are several species of bacteria that can cause BCO, but the most common are Staphylococcus spp., Enterococcus ssp., E. cecorum, E. coli, and S. agnetis among others. Because of this, any BCO vaccine needs to work against multiple species of bacteria.
The lameness, which affects 3-5% of the broiler industry, results in losses of $80-100 million in the U.S. annually due to bird condemnation.
eBeam technology
The researchers used eBeam technology, which generates an electron beam similar to gamma irradiation or x-rays to specifically target shreds bacterial DNA, while preserving the proteins and epitopes necessary for an immune response.
“When we inject those irradiated bacteria into the egg, the egg can recognize the bacteria and start an immune response toward the bacteria. When those eggs hatch, the newly hatched chicks already have an immune response against those bacterial species,” Alrubaye explained.
During the research project, the irradiated bacteria given in ovo reduced the indigence of lameness by >50%.
“Bacterial chondronecrosis with osteomyelitis is caused by multiple different types of bacteria In our vaccine, we only have different species of Staphylococcus, but our future plan is to incorporate more types of bacteria to enhance the vaccine,” said Palmy Jesudhasan, PhD, research microbiologist at the U.S. Department of Agriculture’s (USDA) Poultry Production and Product Safety Research Unit.
The research was funded by research funded by the U.S. Poultry and Egg Association (USPOULTRY).
