S. paratyphi

As a member of the family Enterobacteriaceae. The genus Salmonella is composed of Gram negative bacilli that are facultative and flagellated (motile). There are 3 major surface antigens; the H or flagellar antigen, the O or somatic antigen and the Vi or capsular antigen. Salmonellae also possess the LPS endotoxin characteristic of Gram negative bacteria. This LPS is composed of an O polysaccharide (O antigen) an R core and the endotoxic inner Lipid A. Endotoxins evoke fever and can activate complement, kinin and clotting factors.

Salmonella Paratyphi