Analysis on susceptibility of 53 non tuberculosis mycobacterium isolates to 9 common anti-tuberculosis drugs in Gansu

Objective To understand the susceptibility of non tuberculosis mycobacterium (NTM)isolates to common anti-tuberculosis drugs in Gansu province. Methods The clinical isolates of Mycobacterium were collected to identify NTM by means of PNB/TCH differential media and DNA sequence analysis of 16S rRNA gene. The drug resistance of NTM strains to streptomycin, rifampicin,protionamide (TH₁₃₂₁),isoniazide,sodium aminosalicylate,levofloxacin,ethambutol, kanamycin and pyrazinamide were tested by using absolute concentration method. Results A total of 53 NTM strains were identified from 1 081 clinical mycobacterial isolates,the isolation rate was 4.90%,from which 6 species of NTM were identified including 36 M. intracellulare strains (67.92%),8 M. kansasii strains (15.09%),4 M. avium strains (7.55%),2 M. gordon strains (3.77%),2 M. abscessus strains (3.77%) and 1 M. fortuitum strain (1.89%). Forty nine NTM strains showed different resistance to 9 anti-tuberculosis drugs,the overall resistant rate was 92.45%. The resistant rate to rifampicin was highest (73.58%),followed by that to protionamide (TH₁₃₂₁) (69.81%),isoniazide (67.92%),streptomycin (62.26%), sodium aminosalicylate (60.38%),pyrazinamide (47.17%),ethambutol (28.30%),levofloxacin (26.41%)and kanamycin (15.09%). Conclusion The susceptibility of NTM to common anti-tuberculosis drugs is poor. It is necessary to use anti-tuberculosis drugs rationally according to the results of drug susceptibility test to increase cure arte and reduce drug resistance.