病原 びょうげん せい大腸 だいちょう きんではありませんでした
byōgenseidaichōkindewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 病原性大腸菌

1. Was not pathogenic E. coli.; Was not a virulent strain of E. coli.

Past/Perfective
Negative
Polite
Formal Register