Shigella dysenteriae (Shigellosis, Food poisoning) شرح بالعربي

ما عليك سوى الانتساب إلى هذه القناة للاستفادة من المزايا:    / @elmicrobiologist   Shigella species cause shigellosis (bacillary dysentery), a human intestinal disease that occurs most commonly among young children. Shigellae are nonmotile, unencapsulated, and Lac– . Most strains do not produce gas in a mixed-acid fermentation of glucose Shigella are typically spread from person to person, with contaminated stools serving as a major source of organisms. Humans are the only natural host for Shigella species. Flies and contaminated food or water can also transmit the disease. Shigellosis has a low infectious dose: Approximately 10–100 viable organisms are sufficient to cause disease. Therefore, secondary cases within a house-hold are common, particularly under conditions of crowding or poor sanitation. The 40 serotypes of Shigella are organized into four groups (A, B, C, and D) based on the serologic relatedness of their polysaccharide O antigens. Shigella dysenteriae causes the most serious infections, including HUS similar to that caused by EHEC O157H7 S. dysenteriae type 1 produces Shiga toxin, which is structurally and genetically very similar to Shiga-like toxins 1 and 2 produced by E. coli virotypes. All Shiga and Shiga-like toxins are capable of resulting in HUS in susceptible individuals.