Light forge : a microfluidic high throughput platform for rapid and affordable detection of drug resistant strains of tuberculosis.

Abstract

Tuberculosis is one of the most deadly infectious diseases currently plaguing the global community. Unfortunately, lack of accessible, reliable and affordable diagnostic tools in the high disease burden, and resource poor regions such as Sub-Saharan Africa has hampered efforts to eradicate the epidemic. This study documents the development of a microfluidic platform called Light Forge, which is capable of detecting genetic drug resistance signatures in M.tuberculosis DNA. The first phase of this study involved a molecular drug susceptibility assay on 7 strains of M.tuberculosis using the high resolution melt analysis at the rpoB, katG, mab-inhA and gyrA loci with the Light Cycler96 . These findings compared with phenotypic drug susceptibility testing and Sanger sequencing. The results from the preliminary tests showed that the commercial system could detect positive strains at sensitivity estimates of 86%, 17% , 0% and 100% for rpoB, katG, mab-inhA and gyrA respectively. Detection of non-synonymous mutation in gyrA region for all test strains halted further testing. The rpoB gene was selected for on chip profiling with the Light Forge system due to the higher sensitivity. The results from the Light Forge showed that the system was capable of detecting test strains with 100% sensitivity, with modest reproducibility and correspondence with the phenotypic drug susceptibility profiles and the sequencing results. A microfluidic TB assay based on the Light Forge system is on the horizon based on the findings of the study. However, more work is required to incorporate other genes and ultimately design the best-equipped device for the clinical setting.