Mycobacterium Avium complex (MAC) are a subset of nontuberculous mycobacteria (NTM) that
are typically found in the soil and water and can cause pulmonary lung disease. Treatment
of MAC is challenging as it typically requires the use of three or more antibiotics for
over a long period of time and the rate of eradication is suboptimal.

Mac-WGS is an observational study that aims to understand whether new strains of M. avium
are responsible for persistently culture-positive sputum during treatment. Whole genome
sequencing (WGS) will be performed on M. avium isolates from the sputum of patients with
Mav-PD, over the duration of the study. Additionally, home environmental samples will be
collected and sequenced to identify any home source of infection.

As an observational study, participants will receive routine standard of care treatment
as per discretion of the physician. Standard of care includes monthly sputum submissions.
The M. avium isolated from the sputum before treatment and every three months while on
treatment (until such time that the sputum becomes culture-negative) will be analyzed by
WGS. If sputum becomes culture-positive again, the isolated germ will also be analyzed by
whole genome sequencing. It will be determined whether the identical strain of M. avium
is always present or whether more than one strain is present which would suggest either
multi-strain infection or the acquisition of new strains of M. avium while on treatment.
Additionally, participant's home environmental samples (i.e. faucets and showerhead
biofilms) will be cultured to determine whether M. avium can be recovered and if so, it
will be analyzed with WGS to assess whether it is the same strain as in the participant's
sputum.