In vitro efficacy of combinations of eight antimicrobial agents against Mycobacteroides abscessus complex

Abstract

A standard treatment regimen against Mycobacteroides abscessus complex (MABC) infections has not yet been established, making MABC difficult to treat successfully. In this study, we sought to develop an active ingredient for the clinical treatment of MABC infections. Methods: We screened 102 MABC strains isolated from clinical specimens using DNA sequence analysis with the housekeeping genes hsp65 and rpoB. Drug susceptibility testing was performed against two subspecies-Mycobacteroides abscessus subsp. abscessus (M. abscessus) and Mycobacteroides abscessus subsp. massiliense (M. massiliense)-using eight antimicrobial agents (clarithromycin, amikacin, doxycycline, imipenem, linezolid, moxifloxacin, faropenem, and rifampicin). The combined efficacy of the antimicrobial agents was investigated using a checkerboard method. Results: We identified 51 isolates as M. abscessus, 46 as M. massiliense, and five as others. Most of the M. abscessus isolates (83.0 %) exhibited inducible resistance to clarithromycin via the expression of the erm (41) gene. Combinations of imipenem with linezolid, moxifloxacin, and rifampicin exhibited additive effects against 81.0 %, 40.7 %, and 26.9 % of M. abscessus, respectively, and against 54.5 %, 69.2 %, and 30.8 % of M. massiliense, respectively. Conclusions: These results demonstrated the potential efficacy of a regimen containing imipenem against M. abscessus and M. massiliense infections.

Minimum Inhibitory Concentrations before and after Antibacterial Treatment in Patients with Mycobacterium abscessus Pulmonary Disease

“…Although only a quarter of isolates (22 isolates, 25.6%) were susceptible to IPM, synergistic effects of IPM with CLR and LZD were reported ( 15 , 16 ), and a systematic review showed that IPM was associated with a higher success rate ( 3 ). Therefore, IPM might be justifiable for MABS pulmonary disease treatment despite the relatively low susceptibility rate.…”

Isoegomaketone exhibits potential as a new Mycobacterium abscessus inhibitor

“…Clarithromycin is a crucial agent for the treatment of complex Mabs infections (Shirata et al, 2020). However, the primary reason for treatment failure is inducible resistance (Nash et al, 2009;Lee et al, 2014).…”