I did not realize sulfa was an antibiotic!

Sulfanilamide is an antibacterial because it's chemically synthesized rather than an antibiotic which is organically derived like penicillin; both are antimicrobials, but the sulfonamides were on the scientific market first.

(Crashing into this thread because I have not yet contrived to see any of this show, but I had an allergy to sulfa drugs for most of my life.)