What is "pathogene"

Pathogene \Path"o*gene\, n. [See Pathogenic.] (Biol.) One of a class of virulent micro["o]rganisms or bacteria found in the tissues and fluids in infectious diseases, and supposed to be the cause of the disease; a pathogenic organism; a pathogenic bacterium; -- opposed to zymogene.

n. (dated form of pathogen English)