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Role of defined bacterial genes and host genetic background in intestinal colonisation of poultry by Salmonella - OZ0314

Poultry continue to be a major source of Salmonella for man. Carcass contamination arises largely by the ability of food-poisoning serotypes of Salmonella to colonise the alimentary tract of poultry in the absence of disease. Egg infection can also arise by surface infection during passage through the cloaca of an infected bird. There is increasing opposition to the use of antibiotics for prophylaxis and elimination of Salmonella organisms from the gut of poultry in the absence of disease. This project seeks to exploit biological measures for control based on vaccination or natural resistence to disease. It is aimed at identifying genes required for survival of Salmonella under the starvation condtions in the chicken gut, including those required for the production of ther energy storage compounds glygogen and polyphosphate. Incorporation of mutations in these genes into live vaccines would induce a non-colonising phenotype which woulod be shed in faeces for a short period, would not be present when birds were slaughtered and thus not enter the food chain. In addition the project aims at setting up breeding populations of inbred lines of chickens which differ in the extent to which they shed Salmonella in the faeces following experimental challenge. If successful it should be possible to use natural breeding programme to derive chickens that are resisitant to colonisation by Salmonella thus reducing reliance on the use of antibiotics in poultry production.
The research supports MAFF policy objectives on food safety and animal health and welfare. The strategic aims are to improve human food safety, reduce the impact of bacterial disease, increase the safety of live vacines and reduce the use of antibiotics.
The aims of the project are:-
1) To determine the role of the energy storage compounds, glycogen and polyphosphate, in the intestinal colonisation and virulence of Salmonella strains for chickens.

2. To establish breeding populations of inbred lines of chicken resistant or susceptible to Salmonella colonisation in order to begin mapping the associated host gene(s) responsible for the observed differences.

This will be carried out by the following technical objectives:

1) To provide mutants in different serotypes of Salmonella with combinations of defined deletions in the genes responsible for glycogen and polyphosphate production and to assess these for intestinal colonisation ability and virulence.

2) To backcross birds from inbred lines which differ in the extent to which they are colonised by Salmonella and to begin mapping the host gene responsible for the difference in resistence to colonisation.
Project Documents
• Final Report : The role of defined bacterial genes and host genetic background in intestinal colonisation of poultry by Salmonella   (89k)
Time-Scale and Cost
From: 1999

To: 2002

Cost: £679,725
Contractor / Funded Organisations
Institute for Animal Health (BBSRC)
Animal Health              
Plants and Animals              
Fields of Study
Animal Health