Molecular Identification of Bacteria Involved in Lameness in Broiler

Lameness is one of the main metabolic diseases related to fast growth in broiler. It is a significant problem in the poultry industry resulting in hundreds of millions of dollars in lost revenue annually. In commercial broilers, the most common cause of lameness is bacterial chondronecrosis with osteomyelitis (BCO). We are using a wire flooring model to induce lameness attributable to BCO in commercial broilers. Our research entails the collection of femoral heads, tibial heads, as well as blood samples from clinically lame birds, culturing bacteria from these sites, and PCR sequencing the 16S ribosomal DNA for species identification.  Our work has shown that most of the lame broilers in a single floor pen are primarily infected with a single species of bacteria.  Surprisingly, the species we identified is not normally associated with poultry. We found that Staphylococcus species are the main species that cause lameness.Staphylococcus agnetis represents the main species isolated from the majority of the bone and blood samples collected from lame broilers that had been hatched in two different hatcheries in two independent experiments. Administration of S. agnetis in the water significantly increased incidence of lameness. Also, Staphyloccus species have been found in the blood of apparently healthy birds. Knowing the exact bacterial species causing lameness and the route of transmission to broilers will lead to the development of measures for mitigating BCO and ultimately reducing the economic losses.