pathogen

A pathogen is simply an organism, be it bacterial, viral or parasitic, that causes disease. Thus "pathogenic bacteria" are the bad guys, as opposed to the "normal flora," those bacteria with which we live in harmony. I suppose we call the normal bacteria our "flora" not because they are plants, but we cannot think of any better term.

Night, Night! Dr. Hull's Common Sense Sleep Solutions© Copyright© Site Information/Disclaimer