Following species of shigella ferment mannitol EXCEPT

Ans. d (Shigella dysenteriae) (Ref. Ananthanarayan Microbiology 7th/pg. 285)# Shigella sonnei, Shigella boydii and Shigella flexneri ferment mannitol, while Shigella dysenteriae does not.# Colonies on MacConkey agar are colorless due to the absence of lactose fermentation. An exception is S. sonnie hich ferments lactose late and forms pale pink colonies.SHIGELLA DYSENTERIAE (SUBGROUP A)# Mannitol nonfermenting bacilli consisting of 10 serotypes.# Indole negative.# Only member of the shigella family that is always catalase negative.# It is the only Species of Shigella that produces exotoxin. Q# Sh. Dysentariae type 1 forms a toxin (shigella toxin), the earliest eg. of an exotoxin produced by a gram negative bacillus.# Three types of toxic ativities noted:- Neurotoxicity