Rapid and simple detection of isoniazid resistant Mycobacterium tuberculosis utilizing DNA chromatography based technique.

Despite the availability of anti-tuberculosis drugs, treatment of tuberculosis has been complicated by drug resistant tuberculosis. Early detection of drug resistance make early appropriate treatment possible. However, the available tools are mainly for rifampicin resistance and the existing isoniazid resistance detection method is expensive, highly technical and complicated to maintain to make them unsustainable for use in developing nations. This study aimed to develop a simple, rapid and low-cost diagnostic kit for isoniazid resistant tuberculosis using single-stranded tag hybridization method targeting an isoniazid resistance conferring mutation. Specificity and sensitivity were assessed by utilizing DNA extracted from 49 isoniazid resistant and 41 susceptible Mycobacterium tuberculosis clinical isolates cultured in Mycobacterial Growth Indicator Tubes. Positive signals were observed at mutant and wildtype lines with the sensitivity and specificity of 100% comparing to sanger sequencing results. In contrast, no positive signal was observed with non-tuberculosis mycobacteria. And the detection limit of this method was supposed to be 103 CFU or less. The STH-PAS method for isoniazid resistant M. tuberculosis detection developed in this study offers a better alternative for conventional phenotypic isoniazid resistance determination which will be of both clinical and epidemiological significance in resource limited nations.