[Clinical application of line probe assay (LiPA) for rifampicin (RFP)-resistant gene examination in sputum from tuberculosis patients].
BACKGROUND
Preventing the spread of drug-resistant tuberculosis is a clinically important challenge. In this effort, rifampicin (RFP)-resistant gene examination by line probe assay (LiPA) was evaluated for its clinical application for rapid detection of tuberculosis.


METHODS
The RFP-resistant gene was examined in a total of 110 samples of sputum obtained from patients that were definitively diagnosed with pulmonary tuberculosis by auto-LiPA. The difference in detection sensitivity between the results of the smear and culture examinations was evaluated. Culture-positive samples were compared with the results of the drug susceptibility test.


RESULTS
Smear-positive samples were LiPA positive in 69 of 73 samples (sensitivity: 94.5%), and smear-negative samples were LiPA positive in 25 of 37 samples (67.6%). More than half of the samples were LiPA positive, even those that were culture-negative or contaminated. Comparison of the 76 culture-positive samples with the results of the drug susceptibility test found that all samples were wild type among the RFP-sensitive strains. Among the 8 RFP-resistant strains, 6 were mutation type. All samples shown to be mutation type were obtained from patients with multi-drug resistant tuberculosis.


CONCLUSIONS
Using LiPA, the amount of smear can be used as a factor for detection of RFP-resistant genes. Detection was possible even with culture-negative and contaminated samples, allowing more rapid diagnosis of patients with multi-drug resistant tuberculosis.
Inagaki
Takayuki
T
Department of Clinical Research, National Hospital Organization Higashinagoya National Hospital, Aichi, Japan.
Yagi
Tetsuya
T
Ichikawa
Kazuya
K
Nakagawa
Taku
T
Moriyama
Makoto
M
Uchiya
Kei-ichi
K
Nikai
Toshiaki
T
Ogawa
Kenji
K
D000904:Antibiotics, Antitubercular / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D012293:Rifampin / Q000494:pharmacology*; D013183:Sputum / Q000382:microbiology*; D018088:Tuberculosis, Multidrug-Resistant / Q000382:microbiology*
D000904:Antibiotics, Antitubercular; D012293:Rifampin