'bacteriotropic' originates from a modern scientific formation combining the prefix 'bacterio-' and the suffix '-tropic'. 'bacterio-' ultimately comes from Greek 'bakterion' meaning 'small staff/rod' (via New Latin 'bacterium'), and '-tropic' comes from Greek 'tropos' meaning 'turn'.

'bacterio-' derives from Greek 'bakterion' → New Latin 'bacterium' → English 'bacteria' and then was used as the combining form 'bacterio-'; '-tropic' derives from Greek 'tropos' and entered scientific English via Neo-Latin forming adjectives like 'tropic' and compound adjectives such as 'phototropic' and 'geotropic', leading to the modern coined adjective 'bacteriotropic'.

Initially the roots meant 'rod' (for 'bacterio-') and 'turn' (for '-tropic'), so the coined sense was literally 'turning toward bacteria'; over time it has been used more broadly to mean 'directed at, attracted to, or specifically affecting bacteria'.