Abstract:Salmonella Typhi is a human-restricted bacterial pathogen that causes a potentially lethal
disease known as typhoid fever, if left untreated. The organism takes its entry into the human body
through the intestinal tract where it attaches to the epithelial cells and invades them. Subsequently, the
bacterium is engulfed by the phagocytic cells (neutrophils and macrophages) and carried to the liver,
spleen and bone marrow. The infection persists if the organism is successful in creating a survival niche
called Salmonella-containing vacuole within the macrophages through unknown mechanisms. We have
taken combined computational and experimental approaches to further explore the host-bacterial
interfaces, both at the levels of intestinal epithelial cells and macrophages. Our experience reaffirms
that in the post-genomic era, available computational tools provide means to search whole genomes of
organisms for the identification of novel virulence genes.