Not sure if it is bacterial. Could be the swim bladder. What is the temp in the tank? I would turn it up and add some salt. Sorry I couldn't help more.
How big is the bass? How long have you had it? Temp is important. The only time I have seen flips; is in new tanks; and tanks that are too warm...Or, should I say, tanks with inadequate agitation, given their heat level. If the water is 82<, and you have poor surface agitation, add some air. If the tank is 82> you might want to bump up the temp.
Bass is 10" roughly. Had him for almost a year.
Temp is 85 since I bumped and salted.
Surface agitation is fine, running 2 ac110's, an xp3 and a massive spongefilter.
ah the dreaded "whirling disease". ive had random fish get this. they never recover and always die. i dont think there is a known cure either. do some google searches and youll see....