'bacillogenous' originates from Neo-Latin/Latin elements: the Latin word 'bacillus' (a diminutive of 'baculum', meaning 'little stick') combined with the suffix '-genous' (from Greek 'genēs' meaning 'born of' or 'producing').

'bacillus' came into scientific Latin from Latin 'bacillus' (diminutive of 'baculum'), and English formed adjectives using the productive combining form '-genous' (from Greek/Latin roots), yielding 'bacillogenous' in modern English medical/bacteriological usage.

Initially related to the literal idea of a 'little stick' (the origin of 'bacillus'), the combined form came to mean 'producing or caused by bacilli' in scientific contexts and retains that specialized sense.