Mycobacterium tuberculosis DNA detection in soluble fraction of urine from pulmonary tuberculosis patients.
METHODS
A tertiary care and research institution in Italy.


BACKGROUND
Small DNA fragments from cells dying throughout the body have been detected in urine (transrenal DNA [Tr-DNA]).


OBJECTIVE
To test the hypothesis that Mycobacterium tuberculosis Tr-DNA could be detected in the urine of pulmonary tuberculosis (TB) patients.


METHODS
We studied 43 patients with culture-confirmed pulmonary TB with no evidence of extra-pulmonary involvement, 10 patients with pulmonary diseases other than TB and 13 healthy controls. DNA was extracted from urine and analysed by semi-nested polymerase chain reaction (PCR).


RESULTS
M. tuberculosis-specific sequences were found in the urine of 34 of 43 (79%) TB patients studied, whereas all controls were negative. The transrenal nature of M. tuberculosis DNA was demonstrated by two lines of evidence: first, separate analysis of supernatants and sediments from eight of the study patients found seven positive supernatants but only two matched positive sediments. Second, M. tuberculosis-specific sequences were amplified by semi-nested PCR with primers designed for short but not large amplicons.


CONCLUSIONS
Small M. tuberculosis DNA fragments may be detected in the urine of a significant proportion of patients with pulmonary TB. If these observations are confirmed by larger studies, Tr-DNA technology could represent a new approach for detecting pulmonary M. tuberculosis infection.
Cannas
A
A
Spaxen Italia SRL, Rome, Italy. cnnas@immi.it
Goletti
D
D
Girardi
E
E
Chiacchio
T
T
Calvo
L
L
Cuzzi
G
G
Piacentini
M
M
Melkonyan
H
H
Umansky
S R
SR
Lauria
F N
FN
Ippolito
G
G
Tomei
L D
LD
D000328:Adult; D004269:DNA, Bacterial / Q000032:analysis*; D006801:Humans; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000652:urine*; D014556:Urine / Q000382:microbiology*
D004269:DNA, Bacterial