Reptiles do in fact have salmonella in their digestive tracts. To them, it's harmless, just as we have harmless e. coli in ours. Of course, that doesn't mean it can't be transmitted to humans through contact with the reptiles.

Fortunately, this isn't so big a problem; it can be contained easily through diligent hand-washing. The main problem comes from children, who may be harder to control in this respect.