| Part of speech | unknown part of speech |
|---|
| Singular | Plural | |
|---|---|---|
| Nominative | bakterio | bakterioj |
| Accusative | bakterion | bakteriojn |
| Afrikaans | bakterie |
|---|---|
| Catalan | bacteri |
| Danish | bakterie |
| Dutch | bacterie |
| English | bacterium |
| French | bactérie |
| German | Bakterie; Bakterium |
| Greek | μικρόβια |
| Hungarian | baktérium |
| Italian | batterio |
| Low German | baktery |
| Papiamento | bakteria |
| Portuguese | bactéria |
| Saterland Frisian | Bakterie |
| Spanish | bacteria |
| Swahili | bakteria |
| Swedish | bakterie |
| Turkish | bakteri |
| West Frisian | baktearje |