# name
Towards clinical breakpoints for non-tuberculous mycobacteria - Determination of epidemiological cut off values for the Mycobacterium avium complex and Mycobacterium abscessus using broth microdilution

# metadata.dc.description.abstract[].value
Objective: For non-tuberculous mycobacteria (NTM), minimum inhibitory concentration (MIC) distributions of wild-type isolates have not been systematically evaluated despite their importance for establishing antimicrobial susceptibility testing (AST) breakpoints. Methods: We gathered MIC distributions for drugs used against the Mycobacterium avium complex (MAC) and Mycobacterium abscessus (MAB) obtained by commercial broth microdilution (SLOMYCOI and RAPMYCOI) from 12 laboratories. Epidemiological cut-off values (ECOFFs) and tentative ECOFFs (TECOFFs) were determined by EUCAST methodology including quality control (QC) strains. Results The clarithromycin ECOFF was 16 mg/L for M. avium (n=1271) whereas TECOFFs were 8 mg/L for M. intracellulare (n=415) and 1 mg/L for MAB (n=1014) confirmed by analysing MAB subspecies without inducible macrolide resistance (n=235). For amikacin, the ECOFFs were 64 mg/L for MAC and MAB. For moxifloxacin, the WT spanned >8 mg/L for both MAC and MAB. For linezolid, the ECOFF and TECOFF were 64 mg/L for M. avium and M. intracellulare, respectively. Current CLSI breakpoints for amikacin (16 mg/L), moxifloxacin (1 mg/L) and linezolid (8 mg/L) divided the corresponding WT distributions. For QC M. avium and M. peregrinum, ≥95% of MIC values were well within recommended QC ranges. Conclusion : As a first step towards clinical breakpoints for NTM, (T)ECOFFs were defined for several antimicrobials against MAC and MAB. Broad wild-type MIC distributions indicate a need for further method refinement which is now under development within the EUCAST subcommittee for anti-mycobacterial drug susceptibility testing. In addition, we showed that several CLSI NTM breakpoints are not consistent in relation to the (T)ECOFFs.

# metadata.dc.publisher[].value
European Society of Clinical Microbiology and Infectious Diseases

# metadata.dc.relation.ispartof[].value
Clinical Microbiology and Infection, 2023, vol. 29, p. 758-764

# metadata.dc.rights[].value
cc by (c) Fröberg, Gabrielle et al., 2023

# metadata.dc.source[].value
Articles publicats en revistes (Patologia i Terapèutica Experimental)

# metadata.dc.title[].value
Towards clinical breakpoints for non-tuberculous mycobacteria - Determination of epidemiological cut off values for the Mycobacterium avium complex and Mycobacterium abscessus using broth microdilution