these potential pathogens may make safe passage through a low-pH environment where they encounter a large pop- ulation of resident microorganisms that exist in our gastrointestinal tract. There, in conjunction with our mucosal immune system, a delicate dance occurs that may result in no appreciable outcome or a severe disease. The notion of zoonotic disease is a manifes- tation of this evolution, and when a particular agent crosses between species, major attention is given to this event as it represents another significant challenge to public health