Salmonella/Shigella agar

Colonies on Salmonella-Shigella Agar exhibit black-... 

Rainbow Agar Enteric, acetic, and lactic bacteria, E. coli, Salmonella, Shigella, and Aeromonas 18h37°C... 

Xylose lysine desoxycholate agar is also useful for distinguishing Salmonella and Shigella, Salmonella producing red colonies with black centres, and Shigella producing red colonies without black centres. Non-pathogenic coliforms produce yellow colonies. 

Selective-differential media some media have both properties, e.g., MacConkey agar. It is selective as it contains crystal violet and bile salts which inhibit the growth of bacteria other than coliforms. It is differential as it contains neutral red and lactose, which is degraded by coliforms to acid and is detected due to a change in pH. At acidic pH, colourless neutral red becomes red and the colonies develop a red colour. Shigella and Salmonella colonies remain colourless and therefore can be easily distinguished [9,11]. 

Antibacterial - in vitro (Agar plate) at 200.0 pg/disc against Bacillus cereus, B. subtilis. Staphylococcus aureus, 162 Salmonella paratyphia. Vibrio cholera. Shigella boydii, S. flexneri, S. dysenteriae. 

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