'bacteriologically' originates from 'bacteriology', which is derived from the Greek word 'bakterion', meaning 'small rod', and the suffix '-logy', meaning 'study of'.

'bakterion' transformed into the modern English word 'bacteriology', and eventually the adverb form 'bacteriologically' was derived.

Initially, it referred to the study of bacteria, and over time it evolved to describe actions or processes related to this study.