nonantibacterial

The story

1. Proto-Indo-European*né
2. Proto-Germanic*ne
3. Proto-Indo-European*ís?
4. Proto-Indo-European*h₁óynos
5. Proto-Germanic*ainaz
6. Proto-Germanic*nainaz
7. Proto-West Germanic*nain
8. Old Englishnān
9. Middle Englishnon
10. Old Englishnān
11. Old Englishnān-
12. Middle Englishnon-
13. Englishnon-
14. Proto-Indo-European*h₂ent-
15. Proto-Indo-European*h₂énts
16. Proto-Indo-European*h₂énti
17. Ancient Greekᾰ̓ντῐ́ (ăntĭ́)
18. Ancient Greekἀντι- (anti-)
19. Englishanti-
20. Ancient Greekβακτηρία (baktēría)
21. Ancient Greekβακτήριον (baktḗrion)
22. New Latinbactēria
23. Englishbacteria
24. Proto-Indo-European*h₂el-
25. Proto-Indo-European*h₂élisder.?
26. Englishbacterial
27. Englishantibacterial
28. English todaynonantibacterial

From non- + antibacterial.