Question about Cultures - When is it concerning?


New member
I've posted a few times but the quick background is I have a 15 month old son dx CRMS (one disease cause and one variable mutation). He just switched from one clinic that was being reactive to a more proactive clinic last month. The question I have right now is about throat cultures. He has never had a completely clear swab but so far we have been told that nothing he has cultured needed to be treated. I have trusted that and I do still trust that, but I guess I am wondering when a positive culture would warrant treatment or when a positive culture may be something to be more concerned over. He has never cultured pseudo so that's good news and I have understood that to be something more concerning, but at both his last culture at his previous clinic in July and his first culture at his new clinic last month, he cultured "moderate" amounts of Acinetobacter Baumannii. To be clear, I am not doubting the doctor's decision to not treat this. I am just not sure I understand what exactly would trigger treatment in conjunction with a positive culture.

So far the list of things he has cultured include A. Baumanni, Chryseobacterium Indologenes, Staph & sphingobacterium multivorum but A. Baumannii is the only one he's ever had show up twice in a row so it's tweaking my interest a little more. I was told by our first pulmonologist that babies are infamous for having all kinds of things show up in their cultures since they are always putting weird things in their mouths but having it be present for 2 cultures in a row makes me wonder if it it something I should be more aware of.

We are going back to our new clinic this Friday to follow up with the doctor and I do want to have this discussion with her too but I thought it might be a better discussion if I prepared myself with some guidance here first instead of trying to bumble along as the doctor explains things using medical jargon at a level I might not be able to immediately comprehend.

Any elementary level (or as close to) explanations would be very welcome!


Super Moderator

Let me share our experience and what our doctor said. DS was diagnosed at about 2 weeks and cultured at that time staph. He has had it very single culture since then (he turned 6 in June), and it ranged from "rare" to numerous and sometimes one and sometimes 2 strains. His original CF doctor treated it after the second culture to see if we could get it to go away and also because he was having some coughing, which in retrospect I think was acid reflux. It didn't go away and we never treated again. From what I understand, they don't treat staph unless it is causing issues and we've been blessed that DS has never had a cold or exacerbation, so they never treated it. From age 3-4, he also cultured h-influenza, but hasn't for 2 years, but that also wasn't treated. After his last xray showed the possibility of a tad more inflammation (it wasn't conclusive and could have been the angle, but it went from basically none to minor), I started wondering if the staph being there constantly was causing inflammation and whether we should treat, so I raised with the doctor. She indicated that recent studies show that it is better to leave some things there as it prevents others from getting in the picture and that might well be why he has been so lucky to have never cultured pseudo or MRSA. I recognize the staph but not the other "bugs."

So these are the things I'd suggest asking:
1) Which of these bugs are "normal" CF bugs versus things "normal" kids get?
2) Somewhat relatedly, if they are "normal" CF bugs, does that indicate the diagnosis should be changed? (Frankly, I don't think it matters what you call it so long as the treatment is the same and the insurance doesn't care, but if either of those is impacted by the diagnosis, it might make sense to change to CF if the signs are there, such as the culture
3) When do you treat these specific bugs? And what are pros/cons of treating/not treating?
4) What should I do if a cough starts (or whatever it is that triggers the decision to treat)? Call in? Do you see him or just call in a script?

You might not want to ask all the questions, but I do better knowing what the decision tree is so when faced with something "new," I kinda know what to expect.

Hope this makes sense. Hugs and prayers,


New member
Thank you for the thoughtful response! This is a helpful list of questions to have in hand!

It reminded me that I also want to ask them about what qualifies as an exacerbation - and whether that is a different threshold that they have for a CRMS patient vs a cf patient . I've done some googling about A. Baumannii and it is usually mentioned in articles discussing both it and pseudo as being so it does appear to be something that is worth asking the clinic about. I've been so confused over what symptoms would be worrisome with a positive culture because our old clinic basically took the stance that negative sweat meant no cf meant no extra concerns. Following my son's first culture that showed it (in July) he ended up the next week developing cold symptoms and eventually breathing issues. I took him to urgent care, they did a chest xray and said he had an early lung infection. We were given antibiotics and I tried to contact his clinic about it - I asked the nurse we dealt with if it was something that we should be concerned about given the fact that he had just had a positive culture. She said she'd talk to the doctor and get back to me but they never responded. Which was ultimately the catalyst for me switching him to the new clinic. The antibiotics did seem to do the trick though so I haven't been worrying over it. Although now that he has cultured it again I am just even more confused.

It does feel like I need more clarity from the new clinic on this topic. I'm writing a list up for them of questions so all of your points will be added and I am going to specifically ask them what they think I should do in a situation like I had with our last clinic. It was the second time in 3 months that my son had signs of a lung infection on an xray given to him by urgent care/ER and both times I contacted our old clinic and both times the pulmonologist never replied to my concerns. So I've been sailing blind on this topic.