The video tutorial explains the urease test, a biochemical test to determine if bacteria can break down urea into ammonia, which raises the pH and changes the color of phenol red indicator to hot pink. This test is clinically relevant for distinguishing between lactose non-fermenting gram-negative bacilli like Salmonella, Shigella, and Proteus, with only Proteus expressing urease and producing ammonia.

What color change indicates a positive urease test result?

What distinguishes Proteus from Salmonella and Shigella in the urease test?