Can antbiotics treat gallblader infection?

Yes: Cholecystitis can be treated with antibiotics as a first line of treatment. The surgeon in consultation may decide if a cholecystectomy is needed depending on severity of the condition.

Yes, but: The antibiotics can treat the infection but not the cause of the infection like a gallstone blocking the head of the gallbladder and stopping the outflow of bile. You must see a physician if you really have a gallbladder infection to identify the cause or the infection will immediately recur.