It seems the disease manifests as different forms according to conditions. In cooler water white tufts (columns) and/or saddleback lesions appear. In warmer water (temps above 82'F) the atrophied jaw is common, but these are not mutually exclusive.
My 1st experience came in a trade, where I got 3 beani. When they arrived they were put in quarantine.
Symptoms in the first to go, was intensifying color, hovering in one spot, and inability to eat.

It quickly died, and a summer heat wave hit, bringing tank water temps up into the mid 80sF.
The next to succumb showed classic jaw atrophy symptoms, along with the intense colors, hovering and inability to eat.

Luckily my normal quarantine duration for new fish is 2-3 months, it took that long for all 3 fish to become symptomatic. None ever left quarantine.
After death the tank and all equipment used in or around it was bleached.
The bacteria is gram negative to best treatment would be an antibiotic specifically effective against gram- bacteria.