Which of the following is a true statement regarding Enterobacteriaceae:
Ans. (c) Shigella does not ferments mannitol "Members of enterobacteriaceae rcduce nitrates to nitrites, form catalase but not oxidase." Enterobacteriaceae: lmpoant features Features Escherichia Salmonella Shigella Motility by peritrichous flagella + + - Gas from glucose + + - Acid from lactose + - - Acid from sucrose d - - Growth in KCN - d - lndole + - d MRA/VP + + + Citrate - + - H2S - + - Urease - - - Phenylalanine deaminase (PPA) - - - Arginine dehydrolase d + - Lysine decarboxylase + + - Omithine decarboxylase d + d (d = result different in different species or strains) Remember: - Polar flagella: Vibrio, pseudomonas, legionella, spirilla, campylobacter, H. pylon, spirochetes. - V. parahemolytic produce both polar and peritrichous flagella.
Motility is by polar flagellum
Glucose is not fermented by all members of the family
All members are oxidase positive
Nitrate reduction negative