Detection of Mycobacterium tuberculosis complex by nested polymerase chain reaction in pulmonary and extrapulmonary specimens.
OBJECTIVE
To compare the performance of nested polymerase chain reaction (NPCR) with that of cultures in the detection of the Mycobacterium tuberculosis complex in pulmonary and extrapulmonary specimens.


METHODS
We analyzed 20 and 78 pulmonary and extrapulmonary specimens, respectively, of 67 hospitalized patients suspected of having tuberculosis. An automated microbial system was used for the identification of Mycobacterium spp. cultures, and M. tuberculosis IS6110 was used as the target sequence in the NPCR. The kappa statistic was used in order to assess the level of agreement among the results.


RESULTS
Among the 67 patients, 6 and 5, respectively, were diagnosed with pulmonary and extrapulmonary tuberculosis, and the NPCR was positive in all of the cases. Among the 98 clinical specimens, smear microscopy, culture, and NPCR were positive in 6.00%, 8.16%, and 13.26%, respectively. Comparing the results of NPCR with those of cultures (the gold standard), we found that NPCR had a sensitivity and specificity of 100% and 83%, respectively, in pulmonary specimens, compared with 83% and 96%, respectively, in extrapulmonary specimens, with good concordance between the tests (kappa, 0.50 and 0.6867, respectively).


CONCLUSIONS
Although NPCR proved to be a very useful tool for the detection of M. tuberculosis complex, clinical, epidemiological, and other laboratory data should also be considered in the diagnosis and treatment of pulmonary and extrapulmonary tuberculosis.
São José do Rio Preto School of Medicine, São José do Rio Preto, Brazil.
Adriana Antônia da Cruz
AA
Furini
Adolfo Lutz Institute, Department of Mycobacteria, São José do Rio Preto, Brazil.
Heloisa da Silveira Paro
Hda S
Pedro
Rio Preto University Center, São José do Rio Preto, Brazil.
Jean Francisco
JF
Rodrigues
Oswaldo Cruz Foundation, Aggeu Magalhães Research Center, Recife, Brazil.
Lilian Maria Lapa
LM
Montenegro
Evandro Chagas Institute, Belém, Brazil.
Ricardo Luiz Dantas
RL
Machado
Regional Foundation School of Medicine, São José do Rio Preto, Brazil.
Célia
C
Franco
Oswaldo Cruz Foundation, Aggeu Magalhães Research Center, Recife, Brazil.
Haiana Charifker
HC
Schindler
Lauro de Souza Lima Institute, Bauru, Brazil.
Ida Maria Foschiani Dias
IM
Batista
Fluminense Federal University, Niterói, Brazil.
Andrea Regina Baptista
AR
Rossit
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008168:Lung / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014376:Tuberculosis / Q000175:diagnosis*; D055815:Young Adult