[Drug susceptibility testing for M. tuberculosis with proportion method].
OBJECTIVE
To analyze the feasibility of proportion method in drug susceptibility testing (DST) of M. tuberculosis(MTB).


METHODS
DST was performed to 360 strains of MTB using proportion method and absolute concentration method, 30 of them using both China made and Sigma produced anti-TB drugs. MIC was detected in 19 strains whose results were different from standard ones.


RESULTS
In isoniazid (INH) and ethambutol (EMB), the resistance rate and the accordance rate compared with standard results were significantly higher in proportion method than absolute concentration method (P < 0.01). But in streptomycin (SM) and rifampicin (RFP), they did not show any significant difference. The accordance rates of INH, SM, EMB and RFP between two methods were 81.1%, 92.5%, 83.6% and 98.6%. The DST results using China made and Sigma produced anti-TB drugs had no significant difference.


CONCLUSIONS
The main reason made proportion method differ from absolute concentration method is critical concentration of drugs. China made anti-TB drugs are also qualified for DST purpose.
Liu
Y
Y
Beijing Tuberculosis & Thoracic Tumor Institute, Beijing 101149, China.
Wang
S
S
Na
X
X
D008826:Microbial Sensitivity Tests / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000187:drug effects*