Rapid and efficient detection of extra-pulmonary Mycobacterium tuberculosis by PCR analysis.
METHODS
The diagnosis of extra-pulmonary tuberculosis (EPTB) remains an important clinical problem, primarily because of the inadequate sensitivity of conventional bacteriologic methods for detecting Mycobacterium tuberculosis in extra-pulmonary specimens.


OBJECTIVE
To evaluate whether a IS6110-based polymerase chain reaction (PCR) method can be utilized to detect M. tuberculosis in non-pulmonary specimens.


METHODS
Specimens from 286 Mexican patients with a presumptive clinical diagnosis of EPTB were prospectively examined by Ziehl-Neelsen staining, mycobacterial culture on Löwenstein-Jensen slants, and by PCR. The DNA for PCR was extracted by the buffer lysis method and phenol-guanidine thiocyanate-chloroform. Primers that amplify a 200 bp fragment from the insertion-like M. tuberculosis sequence element IS6110 were utilized.


RESULTS
Our results demonstrate that this PCR method is highly specific (100%) for identifying M. tuberculosis from a variety of specimens including cerebrospinal fluid (CSF), pleural fluid, ascitic fluid, pericardial fluid, urine, and lymph node exudate. Moreover, the sensitivity of PCR for detecting M. tuberculosis in CSF (94%), pleural fluid (94%), ascitic fluid and other extrapulmonary specimens (93%) greatly exceeds the sensitivity of conventional smear and culture methods.


CONCLUSIONS
These results demonstrate that PCR can be a highly specific and sensitive aid in the detection of M. tuberculosis from extra-pulmonary specimens.
Portillo-Gómez
L
L
Molecular Biology in Medicine, Hospital Civil de Belén, CUCS, University of Guadalajara, Mexico. hcivil@udgserv.cencar.udg.mx
Morris
S L
SL
Panduro
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D001202:Ascitic Fluid / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000235:genetics*; D005122:Exudates and Transudates / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008800:Mexico; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D010996:Pleural Effusion / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000382:microbiology* / Q000652:urine
D004269:DNA, Bacterial