E-coli doesn't neccesarily mean infection of the mouth, but they aren't of any good use either anywhere else than in the colon.
The mouth is an orifice that is filled with bacteria naturally, well not e-coli. But the inside of the pussy is in comparison very clean.
E-Coli is everywhere, its naturally occurring in nature, really what causes people to get sick is crippling the bodies immune system by over medicating
Is it possible that E. Coli that is harmless in one person might be pathogenic in another person?
E. coli ≠ Diseases. Some "bad" E. Coli = Diseases.