The colonizing usually happens with the mucoid PA.
Generally speaking here's how it most often goes (someone please correct me if I'm off here) and I know there are exceptions to every rule....but by and large I believe this is accurate.
Patient starts with non mucoid PA (pseudomonas) Non-mucoid is easier to treat and get rid of. Often times if caught early and treated aggressively (oral antibiotics, Tobi and sometimes IV antibiotics) a patient can clear the PA within 1-3 months and it doesn't come back for a long while.
If the patient cannot clear it within a relatively short period of time, it stays around and after a period of something like say 6-18 months it mutates into mucoid PA. This is a little worse because the bacteria actually has a coating around itself that works as a barrier against antibiotics so it's harder to treat. Often times the best anyone can hope for it to knock down the number of bacteria but you can not longer count on eradicating it all. It's at this point when someone is considered to be "colonized with PA"
Does that help?
Hopefully your little guy can clear it out and be done with it -- my daughter cultured PA once when she was about 15 years old -- she is now 19 and has not cultured it again yet.
