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(MAC/MAI) Mycobacterium Avium Complex Pulmonary Disease: Join us

MAC & Bronchiectasis | Last Active: Nov 21 5:21pm | Replies (9354)
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@sueinmn

The sputum culture is the "gold standard" test for NTM - mycobacteria are an extremely slow growing bacteria. Once positive, the susceptibility to specific antibiotics must also be tested.
I too have wondered about PCR testing for mycobacteria, so I went wandering down the dark hole of research....again.
What I found is that is is being tried, but so far there hasn't been a comprehensive large scale study. The best research I have found so far is here: https://jcm.asm.org/content/53/3/930

If you can wade through it, the conclusions seem to be:
PCR testing has promise for diagnosing TB & NTM, but currently the application is limited because specific DNA sequences need to be tested for. So if a strain is known (eg M tuberculosis) the tests are pretty accurate, if not (eg M. avium, strain unknown), not so helpful.
More testing is needed to determine whether PCR testing is effective in identifying low levels of bacteria in the specimen. And side-by-side comparison of PCR and sputum assays of the same sample need to be compared.
Something to watch for in the future!
Sue

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Replies to "The sputum culture is the "gold standard" test for NTM - mycobacteria are an extremely slow..."
cavlover | @cavlover | Feb 19, 2021

Hi Sue, do doctors do a sputum test when diagnosed with bronchiectasis even if you don’t have any symptoms?

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anniepie | @anniepie | Feb 20, 2021

Yes Sue, I've looked at quite a lot of that research too. qPCR machines (Quantitative or Real-time PCR machines) are better now at detecting small amounts DNA of NTMs.
My feeling is they could start beingb a lot 'kinder' to the patient....(especially if you must have bronchoscopies and can't get info out of a hospital without a long wait).
Most of us only want to know if we are still sero-positive for an NTM. They could use a qPCR machine to quickly tell if we are still positive FIRST, (i,e, if they still find any mycobactetial DNA) and relay that info to us much more quickly. Then the exact NTM disease typing could take longer after that. A lot of our tests are just looking for persistence of the same NTM we were originally diagnosed with. To wait so long for any results EACH TIME is very unfair to us patients.
But instead they continue to do it the cheaper, older way, slowly growing the bacteria in a dish, and make us wait and wait and wait.

I'm just grumbling, LOL. But I really do think most other patient groups with other kinds of diseases would complain a lot. The long long delay we face each time just makes me feel like the system doesn't care much about us.

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