The initial screening of gram-negative rods is done by testing for the use of this carbohydrate.
A) Glucose
B) Sucrose
C) Lactose
D) Mannitol

Question

Quizplus · Accepted Answer

Lactose fermenting gram-negative rods will produce acid and gas from lactose fermentation, which can be detected through various biochemical tests, such as the MacConkey agar or Triple Sugar Iron (TSI) agar test. Non-lactose fermenting rods will not produce acid or gas from lactose fermentation. Therefore, testing for lactose utilization is a common initial screening for gram-negative rods.

The Initial Screening of Gram-Negative Rods Is Done by Testing