Exploring Novel Gene Mutations Associated with Fluoroquinolone Resistance in Mycobacterium tuberculosis: Gene Sequencing Results from 275 Clinical Isolates in Chongqing, China

Purpose: . Methods: A total of 275 clinical isolates, consisting of 217 pre-extensively drug-resistant strains and 58 fluoroquinolone-sensitive strains, were included in this study. Gene sequencing was performed on all isolates, and functional assessments through both overexpression and knockout experiments of the gene were conducted to evaluate its effect on fluoroquinolone susceptibility. Results: in Mtb did not alter FQ susceptibility. Notably, two FQ-resistant isolates lacked mutations in any of the five genes sequenced, suggesting the presence of unknown resistance mechanisms. Conclusion: genes may not contribute to FQ resistance in clinical isolates of Mtb in Chongqing, China. Furthermore, our study results also showcased the complexity of mechanisms of FQ resistance in clinical Mtb isolates.