Salmonella Typhi is a bacterium that causes typhoid fever, a type of enteric fever. The molecular basis of its pathogenicity involves various factors. Specific virulence genes and factors enable Salmonella Typhi to survive and replicate within host cells, leading to the characteristic symptoms of typhoid fever.
The Salmonella are gram-negative, facultative anaerobic, non capsulated (except S. typhi/paratyphoid), non-spore-forming, motile rods. They possess a 4.8 Mb genome, variably modified by multiple lysogenic phage genomes, plasmids, and other mobile genetic elements.