Identification of Salmonella Adhesins for Colonization of Chickens

<p>Salmonellosis represents a serious global problem. The incidence of infection resulting from foodborne pathogens continues to increase worldwide despite extensive research and changes at the production and processing levels. Salmonella is one of the leading causes of bacterial foodborne disease outbreaks. The long-term objective of this research is to reduce or eliminate Salmonella contamination of poultry. An understanding of the mechanism of Salmonella adherence to chicken cells could be particularly valuable in the following situations:</p>

<ol>
<li>Developing an efficacious live oral vaccine to prevent Salmonella colonization;</li>
<li>Identifying potential changes in diet that might reduce Salmonella colonization; or</li>
<li>Identifying a means of treating chicken carcasses that may reduce the numbers of attached bacteria.</li>
</ol>

<p>Preliminary data support the hypothesis that Salmonella synthesize a surface protein that is induced by growth in high iron environments and which functions in binding the bacterial pathogen to host cells. The specific goals for this grant period are:</p>

<ol>
<li>To continue studies to identify Salmonella adhesins that function in colonization of chickens;</li>
<li>To determine if any newly identified adhesin is made by other serotypes of S. enterica which colonize chickens;</li>
<li>To determine if induction of an immune response to these adhesins will reduce the ability of S. typhimurium and other Salmonella serotypes to colonize chickens; and</li>
<li>To identify genes which encode proteins regulating the iron-induced adhesin and to evaluate their role in virulence.</li>
</ol>

<p>The investigators' approach will involve using a variety of genetic and molecular biology techniques to identify mutants unable to synthesize adhesins.</p>