Minimum inhibitory concentrations and sequencing data have to be analysed in more detail to set provisional epidemiological cut-off values forMycobacterium tuberculosiscomplex

There is a clear need for a high-quality broth microdilution (BMD) assay for quantitative antimicrobial susceptibility testing (AST) for the Mycobacterium tuberculosis complex (MTBC) [1]. The BMD plate developed by the CRyPTIC Consortium, therefore, represents an important advance [2]. However, the analysis of the resulting data has several limitations. Provisional epidemiological cut-off values for M. tuberculosis complex need to be set carefully C.U. Köser is a visiting scientist at the Department of Genetics, University of Cambridge, and research associate at Wolfson College, University of Cambridge. Feedback from G. Kahlmeter, T. Schön and J. Turnidge was gratefully received. We thank L. Sonnenkalb for clarifications regarding her work.