Clinical characteristics of 42 patients with different subspecies of Mycobacterium abscessus complex pulmonary disease

Abstract

Objective: To compare clinical features and treatment outcomes of Mycobacterium abscessus (M.abscessus) and Mycobacterium massiliense (M.massiliense) pulmonary disease. Methods: A retrospective analysis was performed for 42 patients diagnosed with M.abscessus complex pulmonary disease for the first time in Guangzhou Chest Hospital from January to September 2021. The age of the 42 patients was 17-73 years, including 15 males and 27 females. According to the targeted next-generation sequencing, the patients were divided into M.abscessus group (28 patients, including 10 males and 18 females) and M. massiliense group (14 patients, including 5 males and 9 females). The clinical characteristics, radiological findings, drug sensitivity and clinical efficacy evaluation at 6 months of the two groups were compared. χ2 test and t-test were used for comparison between two groups. Results: The main symptoms in M. abscessus and M. massiliense groups were cough and sputum production. Radiological findings were significantly more frequent in the M. abscessus group than in the M. massiliense group, tree-in-bud sign [22/28 (78.5%) vs. 5/14], nodular bronchiectasis [27/28 (96.4%) vs. 11/14], and lesions involving more than three lung fields [23/28 (82.1%) vs. 7/14]. Both groups showed high levels of resistance to all antimicrobials. The sensitivity rate of the M. massiliense group to clarithromycin was higher than that of the M. abscessus[13/14 vs. 15/28 (53.5%)], and the success rate of treatment was significantly higher in patients with M. massiliense at the 6-month efficacy evaluation. Conclusions: The radiological findings, drug sensitivity and treatment outcomes differ between M. abscessus and M. massiliense pulmonary disease. Improving the identification of bacterial subspecies in clinical practice can effectively improve the diagnosis and treatment.