Role of Alanine Racemase Mutations in Mycobacterium tuberculosis D-Cycloserine Resistance

A screening of more than 1,500 drug-resistant strains of Mycobacterium tuberculosis revealed evolutionary patterns characteristic of positive selection for three alanine racemase (Alr) mutations. We investigated these mutations using molecular modeling, in vitro MIC testing, as well as direct measurements of enzymatic activity, which demonstrated that these mutations likely confer resistance to D-cycloserine.Funding Agencies|University of Otago; Health Research Council; Maurice Wilkins Centre; European Union [FP7-278864-2]; German Center for Infection Research (DZIF); Fundacao para a Ciencia e a Tecnologia, Portugal [UID/Multi/04413/2013, SFRH/BPD/100688/2014, SFRH/BPD/95406/2013]; Wellcome Trust [201344/Z/16/Z]; Medical Research Council UK [MR/K000551/1, MR/M01360X/1, MR/N010469/1]; Indian Council of Medical Research, New Delhi; L2 Diagnostics LLC, New Haven; Pacific Biosciences, Inc.; Illumina, Inc.; European Society of Mycobacteriology; Hain Lifescience; UK Department of Health [HICF-T5-342, WT098600]; Wellcome Trust