Abstract
Tuberculosis continues to plague mankind about three centuries after the first epidemic in modern history in the 17th-18th century. In spite of the advances made in understanding the disease and in diagnostics and treatment options since then, eradicating TB is proving difficult. Cases of antibiotic resistance are complicating both the diagnostic and treatment processes of the disease. A cheap, reliable, sensitive assay using Linear-After-The-Exponential PCR (LATE-PCR was invented in the Wangh laboratory) has been developed to meet the Point-Of-Care (POC) diagnosis needed to effectively combat TB. The nature of the assay and the method of amplification make it applicable to all sample types using less costly technology. Using this Assay, as few as five, rpoB gene copies from Mycobacterium tuberculosis can be selectively amplified in samples containing as many as 58,000 copies of human genomic DNA; PCR efficiency was 105.58%. In addition, the Assay can correctly distinguish thirty-five out of thirty-eight different mutations that are known to cause resistance to rifampicin and all thirty-eight strains are can be distinguished from wild-type drug sensitive rpoB gene sequences using Lights-Off Only Probe technology (also invented in the Wangh Laboratory). Although no mutant strain was scored as wild type, not all mutations could be distinguished from each other. Thus, the resolving power of Lights-Off Only Probes will have to be enhanced if it is clinically important to uniquely distinguish all types of mutations.