- A group of bacteria that normally inhabit the intestinal tract and cause infantile gastroenteritis, summer diarrhea of childhood and various forms of dysentery including epidemic and opportunistic bacillary dysentery. Named for the Japanese bacteriologist Kiyoshi Shiga (1870-1957).
* * *A genus of nonmotile, aerobic to facultatively anaerobic bacteria (family Enterobacteriaceae) containing Gram-negative nonencapsulated rods. These organisms cannot use citrate as a sole source of carbon; their growth is inhibited by potassium cyanide and their metabolism is fermentative; they ferment glucose and other carbohydrates with the production of acid but not gas; lactose is ordinarily not fermented, although it is sometimes slowly attacked; the normal habitat is the intestinal tract of humans and of higher apes; all of the species produce dysentery. The type species is S. dysenteriae. [Kiyoshi Shiga]- S. boydii a species found only in feces of symptomatic individuals; occurs in a low proportion of cases of bacillary dysentery.- S. dysenteriae a species causing severe necrotizing dysentery in humans induced by a virulent shiga toxin found only in feces of symptomatic individuals; the type species of the genus S.. SYN: Shiga bacillus, Shiga-Kruse bacillus.- S. flexneri a species found in the feces of symptomatic individuals and of convalescents or carriers; a common cause of dysentery epidemics, especially in Asia and the Middle East. Now known sometimes to be sexually transmitted through anal intercourse. SYN: Flexner bacillus, paradysentery bacillus.- S. sonnei a species causing dysentery, sometimes milder than that caused by other species. The most common S. species causing disease in the U.S.
* * *shi·gel·la shi-'gel-ə n1) cap a genus of nonmotile aerobic bacteria of the family Enterobacteriaceae that form acid but no gas on many carbohydrates and that cause dysenteries in animals and esp. humans2) pl -gel·lae -.ē also -gellas any bacterium of the genus Shigella3) shigellosis
* * *n.a genus of nonmotile rodlike Gram-negative bacteria normally present in the intestinal tract of warm-blooded animals. They ferment carbohydrates without the formation of gas. Some Shigella species are pathogenic. S. dysenteriae is associated with bacillary dysentery.
* * *Shi·gel·la (shĭ-gelґə) [K. Shiga] a genus of gram-negative, facultatively anaerobic, rod-shaped bacteria of the family Enterobacteriaceae, consisting of nonmotile bacilli that cannot utilize citrate as a sole carbon source and that ferment carbohydrates with acid but no gas production. The genus consists of four species, differentiated by biochemical reactions: S. dysenteriae (subgroup A), S. flexneri (subgroup B), S. boydii (subgroup C), and S. sonnei (subgroup D). Their normal habitat is the intestinal tract of humans and other primates; all species cause bacillary dysentery and shigellosis. Phylogenetically, Shigella is a pathovar of Escherichia coli, but because of long use its treatment as a separate genus has been preserved. The type species is S. dysenteґriae.
Medical dictionary. 2011.