All are true about Shigella except:-

All the given options are true about Shigella except that a large dose is required for infection. Shigella is highly communicable as the infective dose for shigella is very less (10 - 100 bacilli). The production of toxin is also of impoance for virulence but main factor is invasion of the epithelial cells of gut by the organism. Hemolytic uremic syndrome may also occur following infection with S. dysenteriae because of vasculopathy mediated by Shiga toxin. HUS and Haemorrhagic Colitis is produced by S. dysenteriae Type 1 (due to producing Shiga toxin, hence called Shiga bacillus). Bacillary dysentery: manifests with a sudden onset of high grade fever along with abdominal cramp, tenesmus, urgency, and passage of loose, scanty feces containing frank blood and mucus.