Abstract: Objective To detect Mycobacterium tuberculosis（Mtb）resistance to rifampicin (RIF) and isoniazid (INH) by gene chip，and to evaluate their clinical values. Methods Thirty RIF- and INH-susceptible and 50 RIF- and INH-resistant clinical isolates in Mtb were analyzed the mutations of rpoB、katG and inhA genes by (PCR) gene chip and DNA sequencing.  Results The rpoB、katG and inhA genes from 30 RIF and INHsusceptible isolates of Mtb were all wild types by PCRgene chip and DNA sequencing. Of 50 RIFresistant clinical isolates, 3 had wild types of ropB genes, and 41 had ropB mutations by PCRgene chip and DNA sequencing. Six had inconsistent results between PCRgene chip and DNA sequencing. Of 50 INHresistant clinical isolates, 16 had wild types of katG genes, and 31 had katG mutations on codon 315; 30 had wild types of inhA genes, and 7 had inhA mutations at position15. KatG results of 3 isolates and inhA results of 13 isolates were inconsistent between PCRgene chip and DNA sequencing. Conclusion PCR-gene chip might be a rapid and effective method for the detection of Mtb multi-drug-resistant isolates.

Key words: Mycobacterium tuberculosis, Rifampicin, Isoniazid, Drug resistance,bacterial, Oligonucletide array sequence analysis