E. Quiros et al., DIAGNOSIS OF CUTANEOUS TUBERCULOSIS IN BIOPSY SPECIMENS BY PCR AND SOUTHERN BLOTTING, Journal of Clinical Pathology, 49(11), 1996, pp. 889-891
Aims-To evaluate the use of a gene amplification and hybridisation met
hod for detecting mycobacterial nucleic acid as a possible diagnostic
method for cutaneous tuberculosis infection. Methods-Biopsy specimens
from 20 patients with various skin conditions of possible tuberculous
aetiology were studied. Six patients had ulcerative nodules, seven lup
iform lesions, two non-necrotic granulomas, one scrofulous lichen, one
impetigo, one erythematosus lesions, one warty lesions, and one suspe
cted tuberculous lipoma. Biopsy specimens were stained using Ziehl-Nee
lsen stain and cultured in Lowenstein-Jensen medium. DNA was extracted
and then amplified by PCR using primers specific for the Mycobacteriu
m tuberculosis complex. Specificity was confirmed by Southern blotting
. Results-Of the specimens, 30% were positive for mycobacteria on stai
ning with Ziehl-Neelsen stain, 60% were culture positive and 85% PCR p
ositive. Only 35.2% of specimens were positive with all three techniqu
es. A further 32.5% were both culture and PCR positive. All PCR negati
ve samples were also negative when cultured or stained with Ziehl-Neel
sen stain. Of the PCR positive specimens, 29.4% were negative when cul
tured or stained. Conclusions-PCR, using suitable primers, is an effic
ient and sensitive method for the diagnosis of cutaneous tuberculosis.