Abstract: Objective To compare the drug resistance patterns of rifampin(R)-dependent Mycobacterium tuberculosis with R-resistant Mycobacterium tuberculosis. Methods The double-phase Kuang’s agar medium was used to culture and isolate M. tuberculosisfrom the patient’s sputum specimens. Patterns of drug resistance and rifampin-dependence were determined simultaneously.  Results The R-dependent M. tuberculosis strains exhibited higher rates of resistance to all the 8 anti-tuberculosis drugs than the R-resistant strains. The rates of resistance to streptomycin, ethambutol, paraminosalicylic acid and amikacin in these two groups of strains showed significant difference (P<0.05), and the resistance to levofloxacin had highly significant difference (P<0.01). 100% of R-dependent strains and 98.6% of R-resistant strains showed the resistance to multi-drugs. The ratio of extensively drug-resistant (XDR) isolates in the R-dependent strains and R-resistant strains were 14.6% and 5.8% (P=0.05), respectively.  Conclusion All the rifampin-dependent Mycobacterium tuberculosis strains were multi-drug resistant (MDR), which showed high drug resistance rate against first-line and second-line drugs and had more XDR strains.

Key words: Mycobacterium tuberculosis, rifampicin, microbial sensitivity test