Clinical characteristics and antimicrobial susceptibility profiles of Mycobacterium abscessus and Mycobacterium massiliense pulmonary infection

Abstract

IntroductionMycobacterium abscessus complex (MABC) is the most common rapidly growing Mycobacterium species in structural pulmonary diseases and can be life-threatening. This study aimed to assess the clinical characteristics and drug susceptibility statuses of different Mycobacterium abscessus (MAB) subspecies. MethodsDNA sequencing was used to differentiate clinical MABC subspecies isolates. The Clinical and Laboratory Standards Institute guidelines were used to determine vitro susceptibility of imipenem-relebactam, omadacycline, and other conventional antibiotics. Patient's clinical characteristics were collected and analysed. ResultsThere were 139 M. abscessus, 39 M. massiliense, and 1 M. bolletii, accounting for 77.7%, 21.8%, and 0.5% of the MABC isolates, respectively. Patients with M. abscessus pulmonary disease (M.ab-PD) had higher proportions of older adults, tuberculosis history, chronic pulmonary disease, and malignancy than those with M. massiliense pulmonary disease (M.ma-PD). Patients with M.ab-PD had higher rates of bilateral middle- and lower-lobe involvement than patients with M.ma-PD. Both subspecies showed high resistance rates to doxycycline and moxifloxacin, and clarithromycin-induced resistance was more common in M.ab than in M.ma. Relebactam with imipenem resulted in a 2-fold reduction in the minimum inhibitory concentration (MIC) value compared to imipenem alone among MAB; furthermore, the MIC was lower in M.ab than in M.ma. Omadacycline and tigecycline had comparable in vitro susceptibility, and the MIC showed no statistically significant difference between M.ab and M.ma. ConclusionsM.ab is the most prevalent MABC subspecies in the Zhejiang Province. Patients with M.ab-PD have complex underlying diseases and broader lobar lesions. Imipenem-relebactam and omadacycline are promising antibiotics for MABC infection treatment.