Abstract: ObjectiveTo preliminarily explore whether there is a correlation between heat shock protein gene hspX and drug resistance of Mycobacterium tuberculosis （MTB） by comparing the sequence and expression of hspX in MTB with different drug resistance types. MethodsTen strains sensitive to all four first-line anti-tuberculosis drugs （S）, one drug resistance （rifampicin-resistant MTB^R+, isoniazid-resistant MTB^H+, streptomycin-resistant MTB^S+ and ethambutol-resistant MTB^E+） and multidrug resistance （MDR） to isoniazid and rifampicin were selected, respectively. The DNA and RNA of strains in each group were extracted by modified SDS lysis method and TRIzol method, respectively. The existence and expression of hspX gene were determined by PCR and RT-PCR using specific primers. PCR products were sequenced to check the forward and reverse polymorphism, and DNAman software was employed to compare the sequence with the standard strain H37Rv. The difference in the expression of hspX among MTB strains with different drug resistance types was analyzed by pairwise with the sensitive strain group as the control group. ResultsThe specific hspX gene was successfully obtained by PCR. The hspX gene sequence was 97%-99% identical with H37Rv, and there was no significant difference. The mean expression level of hspX through relative quantitation 2^-ΔΔCt in S, MDR, MTB^R+, MTB^H+, MTB^S+ and MTB^E+ strains was calculated as 0.98（0.89, 1.23）, 1.49（1.10, 2.04）, 1.41（0.55, 2.80）, 1.37（0.68, 2.71）, 0.91（0.59, 1.62）and 0.70（0.48, 1.18）, respectively. There was no significant difference in the expression of hspX among different drug-resistant strains groups when the sensitive strain group was regarded as the control group （all P > 0.05）. ConclusionThe hspX gene is conserved in MTB. In natural state, there is no significant correlation between hspX gene and drug resistance of MTB.