Comparison of a DNA based PCR method with conventional methods for the detection of M. tuberculosis in Jos, Nigeria.
BACKGROUND
To achieve early diagnosis and effective treatment of pulmonary tuberculosis, simple and sensitive methods that enhance the detection of Mycobacterium tuberculosis (M. tuberculosis) from clinical specimens are needed. This study compared the effectiveness and suitability of an insertion sequence (IS 6110) based polymerase chain reaction (PCR) assay with conventional methods for the detection of M. tuberculosis from clinical specimens in a resource-limited setting.


METHODS
Sputa from 101 HIV-positive patients and 40 clinical specimens (sputa, gastic wash out, ascitic fluid, pleural fluid and cerebrospinal fluid) collected from children (HIV status unknown), all suspected for pulmonary tuberculosis at the Jos University Teaching Hospital, Jos, (JUTH) Nigeria, were examined by Ziehl Neelsen (ZN) smear microscopy, Lowenstein Jensen's (LJ) egg-based culture, and PCR methods for the detection of M. tuberculosis.


RESULTS
Mycobacteria was detected in 45/101 (44.6%) of the specimens from the HIV-positive patients and comprised of 6% ZN(+)culture(+)PCR(+), 4% ZN(-)culture(+)PCR(-), 16% ZN(-)culture(+)PCR(+) and 19% ZN(-)culture(-)PCR(+). Twenty-two of forty (55%) children were positive with 0% smear microscopy; 4/40 (10%) culture(+)PCR(+); and 18/40 (45%) culture(-)PCR(+). The sensitivity and specificity of the PCR for the HIV-positive patients were 85% and 74% respectively against 23% and 100% for ZN smear microscopy.


CONCLUSIONS
The IS6110 PCR is a rapid and sensitive method that is specific for the M. tuberculosis complex group. It is simple in our experience and increased the detection of M. tuberculosis from the specimens examined. We suggest its use for the detection of M. tuberculosis in high TB and HIV burden areas.
Ani
Agatha
A
Department of Medical Microbiology University of Jos, Jos, Nigeria. aniaek@yahoo.com
Okpe
Silvanis
S
Akambi
Maxwell
M
Ejelionu
Emeka
E
Yakubu
Bitrus
B
Owolodun
Olajide
O
Ekeh
Peter
P
Oche
Agbaji
A
Tyen
Dinchi
D
Idoko
John
J
D001431:Bacteriological Techniques / Q000379:methods*; D001826:Body Fluids / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D006801:Humans; D008853:Microscopy / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D009549:Nigeria; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis*
D004251:DNA Transposable Elements; D004269:DNA, Bacterial