In the laboratory, the screening procedure used to differentiate Salmonella and Shigella from other Enterobacteriaceae includes testing for their inability to:

Inability to ferment lactose is used to differentiate Salmonella and Shigella from other Enterobacteriaceae. Option 1, 3, 4 Enterobacteriaceae propeies: Ferments glucose Reduces nitrate to nitrite Oxidase test negative Catalase positive (except Shigella dysenteriae type-1) Motile, except Shigella and Klebsiella. Option 2 Lactose fermenters Non Lactose fermenters Escherichia Klebsiella Enterobacter Other members of Enterobacteriaceae family including Salmonella and Shigella.