To discover phytochemical replacements for antibiotics in broiler feed, contributing to a reduction in opportunities for bacterial resistance to antibiotics.

The aim of this project is to identify phytochemicals which can exert useful effects at the level of microbes and/or the host and which can enhance resistance against major infectious diseases of poultry (Eimeria spp and avian pathogenic E. coli). The effects sought are:

1. weakening of invading microorganisms,
2. induction of anti-inflammatory stress proteins in gut microbiota and host cells,
3. promotion of gut epithelial integrity through induction of intracellular protective stress proteins,
4. strengthening host immunity through immuno-stimulatory effects.

At IRAS-VPH in vitro testing will take place on the influence of six phytochemicals on the ability of Eimeria spp. to invade cultured epithelial cells. Furthermore, effects of the same six substances will be tested against particular virulence characteristics of avian pathogenic E. coli, namely temperature-sensitive haemagglutination (Mannose-resistent haemagglutination assay using chicken erythrocytes), development of fimbriae (immunogold labelling and electron microscopy) and motility/swarming (motility assay on agar, Western blot against flagellin).

Madin-Darby bovine kidney cells in culture will be used as a model of the chicken gut epithelial surface.