Pulmonary Disease Caused by Rapidly Growing Mycobacteria: A Retrospective Study of 44 Cases in Japan

Abstract

Background: The features of pulmonary disease caused by rapidly growing mycobacteria (RGM) have not been sufficiently documented. Objectives: To establish these features, we retrospectively evaluated 44 patients. Methods: We screened respiratory isolates at the National Toneyama Hospital (Osaka, Japan) between 2003 and 2007. Diagnosis was based on the latest guidelines of the American Thoracic Society. The patients were classified into 3 types according to their radiographic findings: fibrocavitary, nodular bronchiectatic and unclassified variant. Results: We obtained 1,348 nontuberculous mycobacteria respiratory isolates from 1,187 patients, including 119 RGM isolates from 100 patients. Forty-four of these 100 patients were definitively diagnosed with respiratory disease due to RGM. The most common pathogen was Mycobacteriumabscessus, which accounted for 65.9% of cases, followed by Mycobacterium fortuitum at 20.5%. There was a statistically significant difference in smoking history between patients infected with these 4 RGM species (excluding those with an unknown smoking history; p = 0.039). The overall evaluation of radiographic findings revealed 18.2% as fibrocavitary, 43.2% as nodular bronchiectatic and 38.6% as unclassified variants in these 44 patients. There was a significant difference in radiographic findings between the 4 RGM species (p = 0.002). There was also a significant difference in radiographic findings between M. abscessus and M. fortuitum infected patients (p = 0.022). Conclusions: Patients with M. abscessus seem to have less of a smoking history and more frequent nodular bronchiectatic radiographic patterns than patients with M. fortuitum. In contrast, fibrocavitary patterns might be more frequent with M. fortuitum infection.

Rapidly growing mycobacteria in Singapore, 2006–2011

“…Furthermore, we identified M. abscessus to be the most important RGM in our setting across all specimen sites; M. fortuitum group that was reported to be the most common RGM species in the earlier study was implicated in only 22% of our cases. This finding is consistent with reports from Taiwan [8,14,15] and Japan [16], and it underscores the importance of M. abscessus in the epidemiology of RGM infections in Asia. Unfortunately, M. abscessus is resistant to many currently available antibiotics, with amikacin and clarithromycin as the only two agents with reliable in vitro activity.…”

Distribution of Nontuberculous Mycobacteria by Multigene Sequence-Based Typing and Clinical Significance of Isolated Strains

“…M. fortuitum is included in the rapidly growing group of mycobacteria in which visible colonies can be produced within 7 days, and many clinicians believe that M. fortuitum is not often pathogenic. However, M. fortuitum has been identified as a pathogenic NTM species in several previous studies (29)(30)(31). According to a recent study in a Japanese population, the second-most-common rapidly growing mycobacteria pathogen was M. fortuitum, following M. abscessus (31).…”

“…However, M. fortuitum has been identified as a pathogenic NTM species in several previous studies (29)(30)(31). According to a recent study in a Japanese population, the second-most-common rapidly growing mycobacteria pathogen was M. fortuitum, following M. abscessus (31). It has been shown that lung disease caused by M. fortuitum usually occurs in patients with predisposing factors, such as malignancy, renal transplantation, chronic reflux disease, achalasia, bronchiectasis, or cystic fibrosis.…”

Pulmonary Disease Caused by Non-Tuberculous Mycobacteria

“…In several studies from different regions, infections with rapidly growing mycobacteria were less frequently and infections with M. kansasii , M. malmoense , or M. xenopi more frequently associated with fibrocavitary disease [43,44,54,55,58,60,61,62,63,64,65] (fig. 1), demonstrating a species dependency of the different forms of NTM disease.…”