Xin yixue (May 2023)
Comparison of hspX gene sequence and expression in Mycobacterium tuberculosis with different drug resistance types
Abstract
Objective To 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. Methods Ten strains sensitive to all four first-line anti-tuberculosis drugs (S), one drug resistance (rifampicin-resistant MTBR+, isoniazid-resistant MTBH+, streptomycin-resistant MTBS+ and ethambutol-resistant MTBE+) 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. Results The 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, MTBR+, MTBH+, MTBS+ and MTBE+ 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). Conclusion The hspX gene is conserved in MTB. In natural state, there is no significant correlation between hspX gene and drug resistance of MTB.
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