[Identification of Mycobacterium tuberculosis and rifampin-resistant strains by gene-chips]

To evaluate the gene-chip detecting rifaman-resistance Mycobacterium tuberculosis applied in TB diagnosis and drug-resistant detection.

Mycobacterium tuberculosis and rifaman-resistant strains among 35 rifaman-resistance isolated strains and 102 sputa specimens from TB patients, 27 sputa specimens from other patients were examined the gene-chips. Results obtained were compared with sputum examination, bacteriological culture and standard drug susceptibility test of Mycobacterium tuberculosis.

Thirty-five rifaman-resistance strains were detected by gene-chips and 33 were identified as rifaman-resistance strains and the concordance with the traditional drug susceptibility test of Mycobacterium tuberculosis was 94.29%. Twenty-seven sputa specimens from other patients were examined Mycobacterium tuberculosis by the gene-chips, 2 were positive, the detection specialty was 92.59%. Using three methods detecting Mycobacterium tuberculosis among 102 sputa specimens the positive rate respectively was, sputum examination 35.29% (36/102), bacteriological culture 28.43% (29/102), gene-chip 77.45% (79/102). Among 102 sputa specimens only 29 examined Mycobacterium tuberculosis by the traditional drug susceptibility test and 8 were rifaman-resistant strains. While using gene-chip, there were 20 among 102 sputa specimens identified as rifaman-resistance strains. Among total 55 rifaman-resistance strains detected by the gene-chips, the most frequent mutations were those associated with codon 531 (23 of 55; 41.8%), 526 (15 of 55; 27.27%) and 516 (9 of 55; 16.36%).

Results showed that this was a rapid, simple and highly specific method when using gene-chip to detect Mycobacterium tuberculosis and rifaman-resistant strains.