Shigella Infection - pathophysiology??
Shigella organisms are a group of gram-negative, facultative intracellular pathogens. They were recognized as the etiologic agents of bacillary dysentery or shigellosis in the 1890s. Shigella were discovered over 100 years ago by a Japanese microbiologist named Shiga, for whom the genus is named. Shigella was adopted as a genus in the 1950s. These organisms are members of the family Enterobacteriaceae and tribe Escherichieae; they are grouped into 4 species: Shigelladysenteriae, Shigellaflexneri, Shigellaboydii, and Shigellasonnei, also known as groups A, B, C, and D, respectively. They are nonmotile, non – spore forming, rod shaped, and nonencapsulated. Subgroups and serotypes are differentiated from each other by their biochemical characteristics (e.g., ability to ferment D-mannitol) and antigenic properties. Group A has 15 serotypes, group B has 8 serotypes, group C has 19 serotypes, and group D has 1 serotype.
@koushin Shigella infection is a major public health problem in developing countries where sanitation is poor. Humans are the natural reservoir, although other primates may be infected. No natural food products harbor endogenous Shigella species, but a wide variety of foods may be contaminated. Shigellosis is spread by means of fecal-oral transmission. Other modes of transmission include ingestion of contaminated food or water (untreated wading pools, interactive water fountain), contact with a contaminated inanimate object, and certain mode of sexual contact. Vectors like the housefly can spread the disease by physically transporting infected feces.