The Effect of Propolis on Hatched Eggs Previously Infected With Avian Pathogenic <i>E. coli</i>

We investigated the effect of propolis as a sanitiser on hatched eggs previously infected with avian Pathogenic Escherichia coli (E. coli) (APEC) serogroup O78. A green propolis watery extract at 24% and a native breed hatching eggs have been used in this study. A total number of five virulence genes had been detected in E. coli serotype O78 used in this study indicating the pathogenicity of this isolate. The use propolis as a sanitiser for hatching eggs negatively decreased the hatchability percent and increased the embryonic death percent. However, it had a high strength against E. coli serogroup O78 as it significantly reduced the mean colony-forming unit (CFU) count in livers and yolks 4 days post-challenge and in 1-day-old chicks. Our results indicated the antibacterial effect of a green propolis watery extract at 24% against APEC serogroup O78. However, the effect of low concentrations of the propolis against hatchability and embryonic death rates should be tested.