If your gouramis had TB, then there is a probability that there are TB bacteria in the aquarium and any fish in the tank could have picked up some of the bacteria.
Some fish deal with TB infections better than others. Bottom dwelling fishes seem to cope pretty well, and fish that are not inbred and mutated do better than those that are mutated. The dwarf gouramis are heavily inbred and are genetically weaker than a normal red tail or rainbow shark. The shark is also a bottom dweller so it has that in its favour.
TB is a very slow growing bacteria and in cooler water takes longer to build up in numbers. Keeping the water temperature around 24C (76F) will allow the fish to be warm enough so the fish doesn't stress and cool enough to slow the growth of any TB cells in the water or in the fish.
The TB bacteria generally take a minimum of 6 months to do anything to a fish and in an adult rainbow/ red tail shark, it will probably take a lot longer, perhaps a couple of years when kept in cooler water (76F).
There is also a possibility the dwarf gouramis had another type in internal bacterial infection that is not TB.
I would monitor the fish and see how it goes.
Some fish deal with TB infections better than others. Bottom dwelling fishes seem to cope pretty well, and fish that are not inbred and mutated do better than those that are mutated. The dwarf gouramis are heavily inbred and are genetically weaker than a normal red tail or rainbow shark. The shark is also a bottom dweller so it has that in its favour.
TB is a very slow growing bacteria and in cooler water takes longer to build up in numbers. Keeping the water temperature around 24C (76F) will allow the fish to be warm enough so the fish doesn't stress and cool enough to slow the growth of any TB cells in the water or in the fish.
The TB bacteria generally take a minimum of 6 months to do anything to a fish and in an adult rainbow/ red tail shark, it will probably take a lot longer, perhaps a couple of years when kept in cooler water (76F).
There is also a possibility the dwarf gouramis had another type in internal bacterial infection that is not TB.
I would monitor the fish and see how it goes.
