'bacteriosis' originates from New Latin and Ancient Greek, specifically from the Neo-Latin 'bacterium' (from Greek 'bakterion'), where 'bakterion' meant 'small staff' and the suffix '-osis' (from Greek) meant 'disease or condition'.

'bakterion' (Greek) gave rise to the Neo-Latin 'bacterium'; in modern medical English the combining form 'bacterio-' was attached to the Greek-derived suffix '-osis' to form 'bacteriosis' in the 19th–20th centuries.

Initially it denoted a condition involving bacteria (literally 'a bacterial condition'); over time it has been used specifically to mean 'a bacterial infection' or 'disease caused by bacteria' in medical and veterinary contexts.