Pulmonary tuberculosis in the West Bank, Palestinian Authority: molecular diagnostic approach.

ABSTRACT

OBJECTIVE: To compare the effectiveness and feasibility of an insertion sequence (IS6110)-based polymerase chain reaction (PCR) assay with conventional methods of detecting Mycobacterium tuberculosis and to analyse mutations present in the hot spot region of the RNA polymerase B subunit (rpoB) gene associated with rifampin resistance by DNA sequencing. METHODS: Ninety-five sputum samples from 84 clinically suspected cases of tuberculosis were tested for mycobacterial infections by Ziehl Neelsen smear examination, Lowenstein-Jensen culture and IS6110-based PCR assay. RESULTS: Sensitivity and specificity of the PCR were 94%; the sensitivity of culture was 65%, and of smear tests, 59%. Both smear microscopy and culture had 100% specificity. DNA sequencing data of the 305-bp fragment of the rpoB gene for nine clinical isolates revealed one point mutation at position I572F and double mutations at position S531F in two isolates obtained from two patients who did not respond to the anti-tuberculosis therapy. CONCLUSION: IS6110-based PCR can be used routinely in clinical laboratories for rapid detection of Mycobacterium tuberculosis and thus allow early diagnosis and treatment of any contacts by the cheapest method currently available in the Palestinian Authority region. Rapid detection of rifampin resistance isolates will enable efficient treatment of patients and assist in eradication of the disease in the Palestinian territories.