ick/ich is not a bacterial infection but a parasitic infection. it is best cured with increased temperature, salt, and if needed a formalin and/or malachite green treatment.
it will look like small white dots, almost like grains of salt on the fish. lungfish tend to be highly resistant to ich, and i have never actually seen one get ich, even if other fishes in the tank had it. bichirs and gars (also primitive fishes) are also highly resistant to ich (in other words, you generally have a bad case if any of these types of fishes are showing up with ick).--
--solomon