M. Kurabachew et al., REVERSE TRANSCRIPTION PCR DETECTION OF MYCOBACTERIUM-LEPRAE IN CLINICAL SPECIMENS, Journal of clinical microbiology, 36(5), 1998, pp. 1352-1356
A reverse transcription (RT)-PCR assay targeting the 16S rRNA of Mycob
acterium leprae was developed to detect the organism in clinical speci
mens. A 171-bp fragment was amplified when M. leprae RNA was used as a
template but not when a panel of RNAs from 28 potentially cross-react
ing myobacterial species, seven genera related to Mycobacterium, and t
hree organisms normally found among skin or nose flora were tested. As
few as 10 organisms isolated from infected tissue could be detected,
confirming the sensitivity of the assay. When the test was applied to
clinical specimens, M. laprae was detected in 82% of skin biopsy speci
mens obtained from untreated leprosy patients, while skin biopsy speci
mens from healthy volunteers and patients with other dermatological di
sorders were negative. The sensitivity of the RT-PCR was higher than t
hat of slit skin smear staining for acid-fast bacilli or acid-fast sta
ining of fixed biopsy specimens since 53% of acid-fast bacillus-negati
ve biopsy specimens were RT-PCR positive. Because 16S rRNA is rapidly
degraded upon cell death, the assay may detect only viable organisms a
nd may prove to be useful in assessing the efficacy of chemotherapy.