It does not seem to affect other species aside from various related carp. All new koi should be quarantined. For more information, check out the Mid-Atlantic Koi Club . Each type of bacteria responds differently to various antibiotics so it may take a number of tries to find the antibiotic to treat the bacteria. Care must be taken when adding antibiotics to tanks as they also may kill the biological filter.
Tuberculosis is one bacteria that is hard to fight.
I have lost a number of fish to this gram- positive bacteria. As it grows, the fish appears to become obese with abnormal bulges, often just on one side. Eventually, the bacteria breaks the body wall and kills the fish. Larger fish, like goldfish, may survive open sores that look like infected red, cheesy boils for many months whereas all my small fish died as soon as they ruptured. Also, commonly small fish like danios and white clouds that were born normal developed kinked spines from TB as they aged and the TB set in.