Nontuberculous mycobacteria (NTM) are a group of bacteria that have been found in sputum of growing numbers of people with CF since the 1990s. They are a type of bacteria that live in soil, swamps and water sources.
We know that there are more than 100 types of NTM, and more are being found every year. NTM are very hardy, and can survive many disinfectants and severe environmental conditions.
The group of bacteria that make up the different NTM are “cousins” to the bacteria that cause tuberculosis (TB). These were often called “atypical mycobacteria” in the past. Despite this relationship, NTM are distinctly different and cause a different disease than tuberculosis.
Key characteristics of NTM
- Grow slower. NTM grow much slower than regular types of bacteria, making them much harder to diagnosis as they may not become apparent on laboratory cultures for up to 8 weeks. This slow growth makes the infection harder to treat as well.
- Almost always in the lungs. NTM can cause infections in many other diseases and medical conditions besides CF. Although NTM can cause infections in many organs of the body, for people with CF the infection is nearly always in the lungs. NTM enter the lungs directly through exposure from the environment, not from other friends or family members with CF.
People with CF need to be careful to not expose other people with CF to respiratory infections through direct close contact. You can learn about avoiding germs in the “Basics of Infection Control” section of the Adult Guide.
- Diagnosed through sputum. NTM lung infections are diagnosed by special cultures of your sputum. Sputum samples can be gotten either by coughing, from sputum-induction (with saline) or from bronchoscopy (when a fiberoptic tube is passed into your lungs to get samples). The sample needs to be processed in a certain way to remove Pseudomonas aeruginosa and other usual bacteria. The final results may not be available for months.
The infection can only be diagnosed if these special cultures are ordered by your doctor. If cultures for NTM are repeatedly positive, your doctor may get a high-resolution chest CT scan to help confirm the diagnosis and find out the extent of the lung disease.
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