Molecular surveillance of antimicrobial resistance and transmission pattern of in Chinese leprosy patients.

Reports on antimicrobial resistance (AMR) of relationship with bacteriological index (BI), and transmission in China are limited. We investigated the emergence of AMR mutations, the relationship between BI and AMR in complete, moderate and lack of BI decline cases, and molecular epidemiological features of AMR cases by enrolling 290 leprosy cases from four endemic provinces. Seven (2.41%), one (0.34%), five (1.72%), one (0.34%), and one (0.34%) strains had single mutations in , , , , and respectively. Double mutations in and , and , and and were observed in one (0.34%) strain each. Mutated strains occurred in three out of 81 (95% CI-0.005-0.079, = 0.083) cases with complete BI decline, in seven out of 103 (95% CI 0.018-0.117, = 0.008) cases with moderate BI decline, and in four out of 34 (95% CI 0.003-0.231, = 0.044) cases with lack of BI decline. Most of these mutated strains were geographically separated and diverged genotypically. AMR mutations may not be the main cause of the lack of BI decline. The low transmission of AMR strains at the county level indicates an ongoing transmission at close contact levels.