Abstract: Objective To explore the role of gidB mutation in the mechanism of streptomycin resistance in Mycobacterium tuberculosis clinical isolates.Methods Sixty streptomycin-resistant and thirty streptomycin-susceptible Mycobacterium tuberculosis clinical isolates were determined MIC and analyzed gidB,rpsL and rrs gene mutations by DNA sequencing.Results twenty percent of streptomycin-resistant isolates were found only harboring gidB mutation while 80% concurrently with rpsL or rrs mutations.There were also gidB mutations in streptomycin-sensitive isolates.Conclusions The role of gidB mutation in the mechanism of streptomycin resistance in Mycobacterium tuberculosis clinical isolates is uncertain.

Key words: gidB, Gene mutation, Mycobacterium tuberculosis