A Convergence of Pathogens: Exploring the Co-infection of Mycobacterium Avium and M. Abscessus

Abstract Nontuberculous mycobacterial (NTM) lung disease encompasses disorders caused by Mycobacteria species other than Mycobacterium tuberculosis. While NTM infections primarily affect individuals with pre-existing lung conditions, such as chronic obstructive pulmonary disease (COPD), bronchiectasis, cystic fibrosis, and primary ciliary dyskinesia, they can also occur in individuals without any prior lung disease. NTM lung disease refers to a group of respiratory disorders caused by mycobacteria species other than Mycobacterium tuberculosis, the bacterium responsible for tuberculosis. While NTM infections primarily affect individuals with pre-existing lung conditions, such as chronic obstructive pulmonary disease, bronchiectasis, cystic fibrosis, and primary ciliary dyskinesia, they can also occur in individuals without any prior lung disease. The most commonly implicated group of NTM species is the Mycobacterium avium complex (MAC), which includes M. avium, M. intracellulare, and M. chimaera, responsible for roughly half of all NTM-related infections. Other NTM species that can cause lung disease include M. abscessus, M. kansasii, and M. fortuitum, among others. This discussion will specifically focus on the co-infection of the lungs by two distinct NTM species. We present the case of a 71-year-old patient with a history of sarcoidosis, treated with prednisone and in remission since 2013. After contracting COVID-19 in 2022, he developed worsening shortness of breath and cough. Imaging showed bilateral reticular opacities, suggesting progressive fibrosis or pneumoconiosis, along with signs of infection in the left lower lung. Bronchoscopy with bronchoalveolar lavage (BAL) revealed Mycobacterium abscessus, Haemophilus influenzae, and Aspergillus species, including Penicillium. He was treated with antibiotics but returned two months later with similar symptoms. A follow-up BAL revealed Mycobacterium avium complex (MAC). The co-presence of M. abscessus and MAC despite treatment was notably rare and raised concerns about the complexity of his infection.NTM causes difficult-to-treat opportunistic infections, most frequently of the lungs, and co-infections with fungi like Aspergillus fumigatus are not only difficult to identify as diagnostic criteria for NTM-PD and chronic pulmonary aspergillosis (CPA) overlap, but also associated with higher mortality. Precise identification of NTM organisms is crucial to predict treatment outcomes in mixed infections. Coinfection with different species of NTM is uncommon, and usually occurs in patients with advanced immunosuppression. The patient's history of sarcoidosis and recent COVID-19 infection likely increased his vulnerability to NTM lung disease. https://www.atsjournals.org/doi/abs/10.1164/ajrccm-conference.2024.209.1_MeetingAbstracts.A6295; https://pubmed.ncbi.nlm.nih.gov/30104265/; https://erj.ersjournals.com/content/54/1/1900117