Progress 05/01/08 to 09/30/11
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?
We have performed extensive genotyping on APEC populations to determine the prevalence of ColV plasmid-associated genes. The definition of the APEC pathotype has thus been refined to a subset of plasmid-encoded genes that are predictive of its virulence potential. We also identifed a rare horizontal transfer event of a ColV plasmid into Salmonella Kentucky. Wedemonstrated that this plasmid is highly prevalent and highly conserved among Salmonella Kentucky isolates from poultry. Furthermore, this plasmid was shown to play a role in extraintestinal infection and survival in chickens. We performed RNA- Seq of ColV plasmids to define the baseline transcriptome of the ColV plasmid and its differential expression in the avian host.
Publications
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Progress 01/01/10 to 09/30/10
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?
We have performed extensive genotyping on APEC populations to determine the prevalence of ColV plasmid-associated genes. The definition of the APEC pathotype has thus been refined to a subset of plasmid-encoded genes that are predictive of its virulence potential. We also identifed a rare horizontal transfer event of a ColV plasmid into Salmonella Kentucky. We demonstrated that this plasmid is highly prevalent and highly conserved among Salmonella Kentucky isolates from poultry. Furthermore, this plasmid was shown to play a role in extraintestinal infection and survival in chickens. We performed RNA-Seq of ColV plasmids to define the baseline transcriptome of the ColV plasmid and its differential expression in the avian host.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2010
Citation:
Johnson, T.J., Jordan, D., Kariyawasam, S., Stell, A.L., Bell, N.P., Wannemuehler, Y.M., Alarcon, C.F., Tivendale, K.A., Logue, C.M., and Nolan, L.K. Sequence analysis and characterization of a transferrable hybrid plasmid encoding multidrug resistance and enabling zoonotic potential for extraintestinal pathogenic Escherichia coli. Infection and Immunity 78:1931-1942.
- Type:
Journal Articles
Status:
Published
Year Published:
2010
Citation:
Johnson, T.J., Thorsness, J.L., Anderson, C.P., Lynne, A.M., Foley, S.L., Han, J., Fricke, W.F., McDermott, P.F., White, D.G., Khatri, M., Stell, A.L., Flores, C., and Singer R.S. Horizontal gene transfer of a ColV plasmid has resulted in a dominant avian clonal type of Salmonella enterica serovar Kentucky. PLoS One 22:e15524.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: We previously screened over 500 avian E. coli and Salmonella isolates for the presence of ColV plasmid-associated genes. We found that a dominant clone of Salmonella Kentucky exists, harboring the ColV plasmid, that is the most prominent Salmonella strain among poultry and poultry products. We performed a series of chicken colonization and fitness experiments to examine the possible role of the ColV plasmid in S. Kentucky's persistence in chickens. We found that acquisition of the plasmid significantly increased a S. Kentucky recipient's ability to colonize and to cause extraintestinal disease in the bird. Pulsed-field gel electrophoresis on wild type S. Kentucky isolates demonstrated that ColV plasmid-containing strains belong to a single PFGE profile. Plasmid sequencing of several of these plasmids from strains isolated from different sources and geographical locations revealed that they were identical. Taken together, these data suggest the single acquisition of a ColV plasmid by S. Kentucky, and the subsequent emergence of a dominant clonal type in poultry. PARTICIPANTS: Randall Singer, University of Minnesota W. Florian Fricke, University of Maryland Patrick McDermott, Food and Drug Administration David White, Food and Drug Administration TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
We have found that avian Salmonella enterica strains possess ColV plasmids at a surprisingly high rate. These plasmids appear to contribute to the enhanced fitness ability exhibited by these strains. These plasmids are also carried only by certain Salmonella enterica clonal types, suggesting a single rare transfer event that resulted in the transfer of these plasmids from E. coli to Salmonella. The funding provided has allowed us to perform the in vitro and in vivo experiments demonstrating this apparently recent shift in the enteric microbes of poultry. This has direct impact on the poultry industry because it might explain the emergence and dominance recently observed by particular Salmonella enterica Serovars (i.e., Kentucky).
Publications
- No publications reported this period
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: We have screened over 500 avian E. coli and Salmonella isolates for the presence of ColV plasmid-associated genes. We have cured plasmids from wild type isolates representing various evolutionary intermediates of the prototypic ColV plasmid type. These strains have been tested for their growth characteristics in a variety of medias, including LB broth, minimal media, low iron media, chicken serum, human urine, and LB broth of varying pHs. We have isolated bacterial RNA from these different growth conditions and are preparing to perform microarray analysis to identify genes differentially expressed under these conditions. PARTICIPANTS: We have collaborated with the poultry industries in Minnesota and Georgia to perform this work. Furthermore, we have collaborated with faculty at the University of Maryland, the Food and Drug Administration, and the Institute for Genomic Research to obtain isolates and data for this study. The funding has provided training in our laboratory for several undergraduate and Veterinary students. TARGET AUDIENCES: This work will ultimately benefit the poultry industry by elucidating the mechanisms of enhanced colonization by some avian Salmonella enterica strains. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
We have found that avian Salmonella enterica strains possess ColV plasmids at a surprisingly high rate. These plasmids appear to contribute to the enhanced fitness ability exhibited by these strains. These plasmids are also carried only by certain Salmonella enterica clonal types, suggesting a single rare transfer event that resulted in the transfer of these plasmids from E. coli to Salmonella. The funding provided has allowed us to perform the in vitro and in vivo experiments demonstrating this apparently recent shift in the enteric microbes of poultry. This has direct impact on the poultry industry because it might explain the emergence and dominance recently observed by particular Salmonella enterica Serovars (i.e., Kentucky).
Publications
- No publications reported this period
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