How do you differentiate biochemical results between e coli and salmonella?

To differentiate between E. coli and Salmonella, key biochemical tests can be utilized. E. coli typically ferments lactose, producing acid and gas in tests like lactose broth and MacConkey agar, while Salmonella does not ferment lactose and often appears colorless on MacConkey agar. Additionally, Salmonella produces hydrogen sulfide (H2S) on triple sugar iron (TSI) agar, resulting in a black precipitate, whereas E. coli does not. Further biochemical tests, such as urease and indole tests, can also help in distinguishing the two.