Abstract: Objective A rapid method for identificating of M.tuberculosis complex(MTBC) and non-tuberculosis mycobacterium(NTM) were studied by adding ρ-Nitro benzoic Acid(PNB) into the Mycobacter Growth Indicator Tube(MGIT) in BACTEC MGIT 960 system.Methods Five strains were tested PNB inhibition concentration in vitro by MGIT.Results To compare with the method of L？wenstein-Jensen(L-J),a criterion of MGIT PNB 300 ug/ml was used to test the 111 clinical strains,the overall agreement rate was 90.09% compared with L-J.The average reporting time of PNB MIGT was 7.72 days,which was shorter and statistically significant difference in compared with the L-J method(P<0.001).Conclusions The PNB MGIT assay can be considered as a rapid,accurate and practical method for the identification of MTB and NTM.

Key words: ρ-Nitro benzoic Acid, M.tuberculosis complex, Nontuberculosis mycobacterium, Rapid, Mycobacter Growth Indicator Tube