Well it was not cultured,but it was the second lesion that I had gotten.I treated the first with augmentin,and it healed,but another formed 5 wks later.Fortunately I had spoken to someone with some experience with mycobacterium,and he told me that it responded only to antibiotics with gram negative activity,like minocycline or rifampin.And who wants orange eyes and urine?After a six week course of minocycline I have been lesion free for over a year.Process of elimination!I am reasonably certain which tank I got it from,as every fish that went into it wasted away despite eating well.That is the main symptom in fish.After I sterilized that tank there were no further problems with fish or me.Combining that knowledge with my antibiotic experience pretty much proves the diagnosis in my book!