Isolate and identify Salmonella and Shigella species from clinical or food samples with Thermo Scientificâ„¢ Oxoidâ„¢ SS Agar (Dehydrated). Differentiation of Salmonella and Shigella is achieved by incorporation of lactose in the medium. Organisms which ferment lactose produce acid which, in the presence of the neutral red indicator, results in the formation of red colonies. Salmonella, Shigella, and other non-lactose-fermenting organisms appear as transparent or straw coloured colonies on SS Agar. Salmonella and Shigella are major causes of bacterial enteric illness with transmission occurring via the fecal-oral route, person-to-person contact, or by the ingestion of contaminated food or water.SS Agar is a differential, selective medium for the isolation of Shigella and Salmonella species from pathological specimens, suspected foodstuffs etc.Easy-to-read: lactose fermenters (red colonies) are easy to differentiate from non-lactose fermenters like Shigella and Salmonella (straw colorless colonies).Selective: due to the inclusion of selective inhibitory substances brilliant green, bile salts, thiosulphate, and citrate, most Gram-positive and coliform organisms are inhibited.Thiosuplate in combination with iron acts as an indicator of sulphide production, which is indicated by blackening in the centers of the colonies.Not all products are available for sale in all territories. Please inquire. Remelâ„¢ and Oxoidâ„¢ products are now part of the Thermo Scientific brand