Objectives The differentiation between Mycobacterium abscessus subspecies abscessus (M. abscessus) and Mycobacterium abscessus subspecies massiliense (M. massiliense) and determination of the presence of inducible resistance to macrolide antibiotics are important factors in the management of patients with Mycobacterium abscessus complex (MABC) infections. Unlike pulmonary MABC infections, little information on extrapulmonary MABC infections is available. Methods The molecular identification of clinical isolates was performed, and the clinical characteristics and treatment outcomes of 20 consecutive patients with extrapulmonary MABC infections were assessed. Results M. abscessus and M. massiliense each caused 10 (50%) of the cases. Eight (80%) M. abscessus isolates that had inducible resistance to clarithromycin harbored an intact erm(41) gene of the T28 variant, whereas two (20%) M. abscessus isolates had the C28 erm(41) variant and were susceptible to clarithromycin. All M. massiliense isolates had a truncated erm(41) gene and were susceptible to clarithromycin. The drug susceptibility profiles other than clarithromycin were similar for the M. abscessus and M. massiliense isolates. Of the 20 patients, 17 (85%) showed a favorable outcome, including all patients with M. massiliense infection and 70% (7/10) of patients with M. abscessus infection. Favorable outcomes were associated with M. massiliense and M. abscessus isolates with a non-functional erm(41) gene (p = 0.049). Conclusions Precise species and subspecies identification and the determination of macrolide susceptibility are recommended for the optimal treatment of extrapulmonary MABC infections.
Bibliographical noteFunding Information:
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and Future Planning (NRF-2015R1A2A1A01003959) and by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI) funded by the Ministry of Health & Welfare, Republic of Korea (HI15C2778). The sponsor had no role in the design of the study, the collection and analysis of the data, or the preparation of the manuscript.
All Science Journal Classification (ASJC) codes
- Microbiology (medical)
- Infectious Diseases