[Ancesthntr]

Corrections:

1) and, THUS, germs

2) second, it doesn’t strengthen the RESISTANCE OF bacteria.

[Don W]

It kills the weaker/more susceptible bacteria, thereby leaving the stronger/less susceptible ones.

I always considered the word germs to be a catch-all for the various pathogens out there, be they bacteria, or virii.

Dictionary:

3. germ (n.)
a minute life form (especially a disease-causing bacterium); the term is not in technical use