Research/Genomic approaches to novel vaccines
From Poultry Hub
Title: Genomic approaches to novel vaccines
Project Leader: Glenn Browning at The University of Melbourne funded by Poultry CRC (Project 03-09)
Duration of Project: Now completed (14 May 2004 to 31 October 2007)
Contents |
Project overview
There is a clear need for the development of new vaccines and alternative approaches to vaccination in poultry in order to effectively control a number of infectious diseases that remain a significant cause of economic loss and continue to affect the welfare of poultry. The availability of methods to sequence and manipulate the genomes of pathogens presents new opportunities to address these concerns.
Project objectives
- Identify the genes responsible for virulence in avian pathogenic E. coli;
- Assess the virulence of E. coli carrying deletions in these virulence genes;
- Develop tools suitable for improved surveillance of poultry sheds for dangerous levels of avian pathogenic E. coli; and
- Examine the potential for in ovo vaccination of poultry with whole genomes of attenuated viruses.
Project progress
This project has been completed and the Final Report will soon be available from the Poultry CRC.
The complete sequence of the virulence plasmid of avian pathogenic E. coli strain E3 was determined and this sequence annotated to identify all the genes contained within it. Deletions were made in specific regions of the plasmid and the effect of these deletions on virulence tested. This has enabled the most important regions contributing to virulence to be identified. Assays were developed to detect the most important virulence genes and used to identify virulent E. coli in isolates from recent clinical cases of disease.
A variety of constructs containing the genome of attenuated strains of Chicken Anaemia Virus (CAV) were tested for their infectivity in ovo, but none were found to be able to establish infection. Constructs containing duplications of the genome have been derived, and these are more likely to be infectious.
