You have isolated a bacterium that you believe to be the causative agent of a new disease in frogs. How would you test the third of Koch's postulates?
A) Determine the shape of the bacterial cells.
B) Inject the bacteria into a healthy frog.
C) Isolate the bacterium from a sick frog.
D) Show that the bacterium is not present in healthy frogs.
E) Grow a pure culture of the bacterium outside the frog.

Question

Quizplus · Accepted Answer

The third postulate states that the suspected pathogen must be able to cause the disease in a healthy host. Injecting the isolated bacterium into a healthy frog would allow for observation of disease development, indicating whether the bacterium is indeed the causative agent of the new disease in the frogs.

You Have Isolated a Bacterium That You Believe to Be