My daughter cultured Steno in January, and was treated with IVs and Bactrim because it was causing symptoms. High fever, increased cough, weight loss.... She is still on the oral Bactrim and has been since January, but still cultures it.
It used to be listed as pseudomonas, but has since been seperated. I know another CFer who bounces back and forth between pseudo and Steno, her mom thinks it is just a difference in the way the labs read it, but that is her opinion not mine.
My daughter has not cultured pseudo in over 2 years.