Progress 08/01/04 to 07/31/08
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The uvrY gene is highly experssed in-vivo within poultry (clone # ecs-57, 15). These results indicate that the BarAUvrY two-component system may be regulating adaptation and virulence. Indentifying BarAYvrY-regulated APEC-specific genes should provide a better understanding of the virulence mechanism and help in the development of future intervention strategies that will be beneficial to poultry breeders. The multiple mutant strains down regulating virulence that we have developed have all the characteristics of a live attenuated vaccine.
Publications
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Progress 01/01/05 to 12/31/05
Outputs
The longterm objective of the proposed study is to develop a better understanding of the role of a twocomponent adaptive response system, the BarAUvrY system, in APEC virulence. Although the BarAUvrY system has been implicated in the virulence of Salmonella, its role in E. coli virulence is yet to be determined. The current goal of this proposal is to test the hypothesis that, the BarAUvrY twocomponent system regulates virulence in APEC strain O78:K80:H9 by regulating avian pathogen-specific gene expression. The results obtained will help develop a better understanding of the role of this regulatory system in APEC and will be important for future development of intervention strategies for infection. The immediate goals of the project were: Objective 1. Construct a strain-specific library of E. coli O78:K80:H9 sequences that are absent in the E. coli K12 strain, using subtractive genomic hybridization. We have completed two rounds of genomic subtraction. We have
identified few novel APEC specific clones from sequence analysis. These genes appear to contribute to membrane transport and novel adhesins. Objective 2.Identification of avian pathogenic E. coli 078:K80:H9specific genes regulated by the BarAUvrY twocomponent system. We are in the process of standardizing the microarry printing process of the APEC genes with known, sequenced, E. coli virulence genes. Objective 3. Determining the roles of the BarAUvrY regulated genes in virulence. We have deleted few of the potential APEC specific genes. Deletion of these genes reduces virulence in a embryo lethality model,
Impacts
The uvrY gene is highly expressed in vivo within poultry (clone # ecs-57,15). These results indicate that the BarAUvrY twocomponent system may be regulating adaptation and virulence. Identifying BarAUvrYregulated APECspecific genes should provide a better understanding of the virulence mechanism and help in the development of future intervention strategies that will be beneficial to the poultry breeders. The multiple mutant strains down regulating virulence, that we have developed, has all the characteristics of a live attenuated vaccine. The next phase of experiments with one week-old chickens will determine whether this attenuated starin can be used as an oral vaccine, and whether it will cross-protect chickens from other gram-negative bacteria. Thus the proposed research will support all three goals (research, training, and extension/outreach) of USDA.
Publications
- Christopher D. Herren 1, Arindam Mitra 1, 2, Helena Sahand 1, and Suman Mukhopadhyay 1, 3 * The BarA-UvrY Two Component System Regulates Virulence in Avian Pathogenic Escherichia coli O78:K80:H9. 2005.Infection and Immunity (under review)
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