Role of Nitric Oxide in Salmonella Infection.

Nitric oxide (NO) derivative of l-arginine is an important signaling molecule that mediates a variety of essential physiological processes including vasodilation neurotransmission, and host cell defense. Many types of cells produce NO e.g., smooth muscle cell, endothelial cell, and leukocytes. Host defense functions are known for many bacterial and parasitic infections. In the present study we estimated the levels of serum NO in cases of salmonellosis and in controls. The nitric oxide was estimated by cadmium reduction method, Griess reaction. We observed that in controls the level of NO was (22 ± 2.06) μmol/l and in cases the level was (137.49 ± 29.84) μmol/l. The level of NO was significantly higher than controls (p < 0.001). The raised level of NO could be accounted for by host response to the infection. The host rapidly expresses iNOS, which in turn produces an excess amount of NO. Its cytotoxic effect is by its reactive nitrogen oxide derivative e.g., peroxynitrite. Apart from this it also has anti apoptotic functions. In future one can do follow up study of typhoid cases by bacterial culture.