Pulmonary Mycobacterium abscessus infection is a type of pulmonary non-tuberculous mycobacterial infection where the causative organism is Mycobacterium abscessus.
Pulmonary disease is often indolent, but progressive causing persistent symptoms, a decline of pulmonary function, and impaired quality of life. However, in some situations, the disease can also follow a fulminant course with acute respiratory failure.
Mycobacterium abscessus are Gram-positive, non-motile, acid-fast rods being around 1.0 - 2.5 µm long by 0.5 µm wide.
M. abscessus complex is differentiated into 3 subspecies 5:
- M. abscessus subsp. abscessus
- M. abscessus subsp. massiliense
- M. abscessus subsp. bolletii
There can be considerable overlap in common CT findings of M. abscessus pulmonary infection and Mycobacterium avium intercellulare (MAC).
According to some reports, lobar volume loss, nodule, airspace consolidation, and thin-walled cavities are thought to be more frequently seen in with MAC than M. abscessus 3.
Cavities may be seen in around 17% of patients 4.
Other less common CT findings include:
Treatment and prognosis
M. abscessus is resistant to many antibiotics and thus is very difficult to treat. Combination therapy of intravenous amikacin with cefoxitin or imipenem and an oral macrolide have been recommended by the American Thoracic Society (ATS)/Infectious Diseases Society of America (IDSA).
- 1. Esther CR, Esserman DA, Gilligan P et-al. Chronic Mycobacterium abscessus infection and lung function decline in cystic fibrosis. J. Cyst. Fibros. 2010;9 (2): 117-23. doi:10.1016/j.jcf.2009.12.001 - Free text at pubmed - Pubmed citation
- 2. Jeon K, Kwon OJ, Lee NY et-al. Antibiotic treatment of Mycobacterium abscessus lung disease: a retrospective analysis of 65 patients. Am. J. Respir. Crit. Care Med. 2009;180 (9): 896-902. doi:10.1164/rccm.200905-0704OC - Pubmed citation
- 3. Chung MJ, Lee KS, Koh WJ et-al. Thin-section CT findings of nontuberculous mycobacterial pulmonary diseases: comparison between Mycobacterium avium-intracellulare complex and Mycobacterium abscessus infection. J. Korean Med. Sci. 2006;20 (5): 777-83. Free text at pubmed - Pubmed citation
- 4. Han D, Lee KS, Koh WJ et-al. Radiographic and CT findings of nontuberculous mycobacterial pulmonary infection caused by Mycobacterium abscessus. AJR Am J Roentgenol. 2003;181 (2): 513-7. doi:10.2214/ajr.181.2.1810513 - Pubmed citation
- 5. Lee MR, Sheng WH, Hung CC, Yu CJ, Lee LN, Hsueh PR. Mycobacterium abscessus Complex Infections in Humans. (2015) Emerging infectious diseases. 21 (9): 1638-46. doi:10.3201/2109.141634 - Pubmed