Looks like it.
Bacterial diseas in gall-forming structures is very difficult if not impossible. The reason is that sap has a weird way of flowing in those structures and any treatment will leave some of the bacteria alive. Two things can happen:
1) They bacteria are not hit at all by a treatment. Or
2) They do get hit but not all of them. The survivors will literally eat up their dead friends and come up with a way to resist the antibiotics from those scraps. The next time you treat, they'll all be resistant.
Fire is an option to consider.
