Detection of streptomycin resistance in Mycobacterium tuberculosis clinical isolates by denaturing high-performance liquid chromatography and DNA sequencing

Abstract

To determine the rpsL and rrs gene mutation in Mycobacterium tuberculosis (M. tuberculosis) and compare the consistency between the results of denaturing high-performance liquid chromatography (DHPLC) and those of DNA sequencing. The values of streptomycin minimum inhibitory concentration (MIC) against 215 M. tuberculosis clinical isolates, 115 being streptomycin-resistant and 100 being susceptible by a routine proportional method, were tested by DHPLC. DNA sequencing was conducted to detect the rpsL and rrs mutation. 98 of the 115 streptomycin-resistant isolates (85.2%) harbored rpsL and/or rrs mutation, 76.5% of which being rpsL mutation (88/115). There was no significant correlation between the MIC values and mutation types. No mutation was found in all the susceptible isolates. There was a complete consistency between the DHPLC results and those of DNA sequencing. DHPLC can be regarded as a useful and powerful tool to detect the streptomycin resistance detection in M. tuberculosis.