Nonpathogenic
Incapable of causing disease.
Nonpathogenic bacteria are harmless.
By contrast, pathogenic bacteria can cause disease.
For example, nonpathogenic E. coli are E.
Coli that are innocuous (like most E.
Coli) while pathogenic E.
Coli can make you sick.
The word 'pathogenic' comes from two Greek roots: 'pathos' (disease) + 'genesis' (bringing into being) = literally, bringing disease into being.
Hence, nonpathogenic means not bringing disease into being.