Longitudinal study on Escherichia coli gene variability after application of autogenous vaccine in broiler breeder flocks

Escherichia coli is one of the most common bacterial causes of decreased production and high mortality rates in the poultry industry. It is known for its high genetic diversity which complicates the efficacy of the immunoprophylaxis programs that are the foundation of poultry health protection. E. coli genome sequences isolated from several consecutive flocks on two broiler breeder farms with continuing colibacillosis problems will be analysed. On said farms, flocks were vaccinated with commercial, combined commercial and autogenous, or autogenous vaccine alone. Selected isolates from mentioned farms will be individually analysed and mutually compared based on the housekeeping genes and virulence profiles.