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The development of non-pathogenic strains of Campylobacter jejuni as agents of competitive exclusion in poultry - OZ0603

Recent ACMSF reports have identified the need for further research to develop potential mechanisms by which flock colonisation of campylobacters might be controlled. An alternative approach to competitive exclusion is to administer a non-pathogenic strain of campylobacter, which would then exclude wild-type, potentially pathogenic strains. To ensure absence of pathogenicity to humans, this strain would need to be either naturally attenuated or genetically engineered to remove essential virulence determinants.

This project aims to assess vaccine activity. Immune responses will be measured as surrogates of protective immunity and degree of immune protection determined using models of vaccination and challenge. Work is also proposed to ensure the safety of such a genetically engineered organism during environmental release.

The results may lead to providing at least one strategy to improve the ability of the poultry industry to produce campylobacter-free flocks consistently. They will also enable end-user demand for microbiologically safe poultry meat to be satisfied, at least in terms of campylobacter, thereby significantly reducing campylobacteriosis in humans. This project will also provide academic information about the bacterial factors required for colonisation of the avian host gut mucosal surface.
obj. no Completed by data Description
01 31/03/2000 To determine and characterise the potential of selected highly colonising, naturally attenuated, or genetically engineered to delete a known virulence factor, strains of C. jejuni to competitvely exclude subsequent challenges with C. jejuni using an experimental oral chick model of colonisation.

02 31/03/2000 To develop the chick colonisation model to mimic more closely the broiler house environment for testing competitive exclusion.

03 31/03/2001 To identify C. jejuni chicken colonisation factors by comparison of the proteome of poorly colonising strain 11186 with stronger colonisers.

04 31/03/2001 To determine the contribution of immune response to protection using the selected competitive exclusion strain.

06 31/03/2000 Tp present recommendations on the potential of competitive exclusion for the control of C. jejuni on poultry.
Time-Scale and Cost
From: 1998

To: 2001

Cost: £349,560
Contractor / Funded Organisations
Veterinary Laboratories Agency
Animal Welfare              
Plants and Animals              
Fields of Study
Animal Health