Characterizing the gene mutations associated with resistance to gatifloxacin in Mycobacterium tuberculosis through whole-genome sequencing

•Mutations conferring resistance to gatifloxacin (GAT) remain inadequately characterized.•123 GAT-resistant mutants were isolated and subjected to whole-genome sequencing.•Sixty-eight of 123 mutants had gyrA gene mutations (G280A, A281G, G280T and G262T).•The remaining mutants harboured gyrB gene mutations (A1495G, C1497A, C1497G and A1503C).•Mutations in the gyrA and gyrB genes are the main mechanisms of resistance to GAT.