Objective: To investigate the molecular mechanism of INH-resistance and the relationship between INH-resistance and KatG mutations.
Methods: Use the primers designed from the 5' end of the KatG gene to amplify 282bp fragments from INH-susceptible and -resistant M. tuberculosis isolates. Single strand conformation polymorphism (SSCP) for their PCR products were analysed.
Results: No katG gene sequence deletion was observed, mutations were detected in 17 of 30 INH-resistant strains and no gene perturbations were shown in 16 INH-susceptible isolates.
Conclusion: The results suggested that mutation in katG gene was one of the most important INH-resistant mechanisms in M. tuberculosis.