Expression Analysis of Thirteen Genes in Response to Nifurtimox and Benznidazole in Mexican Isolates of Trypanosoma cruzi by Digital PCR

Abstract

Despite being the most relevant and critical option for managing Chagas disease, pharmacological therapy is currently limited by the availability of only two drugs, benznidazole and nifurtimox. Their effectiveness is further restricted in the chronic phase of the infection, as they induce severe side effects and require prolonged treatment. Additionally, the use of these drugs can lead to the emergence of substantial resistance problems, compounded by the potential natural resistance of some parasite isolates. This study analyzes the expression of 13 genes by digital PCR in four Mexican T. cruzi isolates treated with NFX and BZN. Each isolate exhibited a unique combination of enzyme expression in response to the oxidative stress induced by the antichagasic agents. Notably, we observed the overexpression of cruzipain (CZP), L-threonine dehydrogenase (TDH), and detoxification-related enzymes such as Glutathionyl spermidine synthetase (GST) and Superoxide dismutase-A (SOD). These findings highlight the need for further studies to elucidate the molecular mechanisms underlying this resistance, which pose both unexpected challenges for Chagas disease therapy and a biological barrier to the action of these drugs. These findings highlight the need for further studies to understand how these resistance mechanisms contribute to treatment failure and constitute a biological barrier to drug action.

Keywords: Benznidazole; Mexican isolates; Nifurtimox; Resistance genes; Trypanosoma cruzi; dPCR.