Biosensors & Bioelectronics

Biography

Biography: Thu-Hoa Tran-Thi

Abstract

Tuberculosis still infects 8.8 million and kills 1.3 million persons per year. Early diagnosis of the infection would reduce the disease’s effects. Many teams over the world have worked to improve in selectivity and time-consumption the standard diagnostic methods based on sputum analysis and bacteria culture. Cepheid has commercialized an Xpert MTB/Rif test with the result in 2 hours. Despite its reduced price for developing and high TB burden countries, the system still suffers from a drawback: the calibration needs to be performed by a trained technician using specialized equipment. Therefore, the search for easy-to-use, low-cost and selective tests remains a challenge. Non-invasive detection of a specific metabolite marker of Mycobacterium tuberculosis (M-Tb) present in cultures and patients’ breath is a promising method. A few metabolites of M-Tb in culture supernatants were found to be specific for M-Tb, including nicotinic acid (NA), methyl phenylacetate, p-methyl anisate, methyl nicotinate, and 2-methoxy biphenyl. Interestingly, NA could also be detected in the breath of patients with active tuberculosis. Based on these findings, our objective has been to propose a new easy-to-use method for NA detection in biological samples and in particular in a breath condensate. The method is based on analysis of the luminescence increase of Tb3+ complexes in the presence of NA due to the energy transfer from the excited ligand. We will show the limit of detection and the strategy developed to circumvent interferences from other metabolites. The method’s cost is evaluated and compared with the WHO-endorsed Xpert MTB/RIF test.