Evaluation of Trypanosoma cruzi parasitic load by real-time PCR and blood culture in long-term kidney transplant recipients.

INTRODUCTION: Acute Chagas disease involving reactivation can occur after organ transplant, and follow-up by direct parasitological or molecular methods is essential for monitoring the parasitic load in such patients. In contrast, there is a little data on the parasitic load in long-term organ recipients. In this study, we examined the parasitic load in long-term kidney transplant patients and assessed the possibility of late Chagas disease reactivation. METHODOLOGY: Blood cultures and real-time PCR were used to assess the parasitic load in four immunosuppressed patients who underwent kidney transplants (between 1996 and 2014) and were also treated for parasites. RESULTS: There were no positive blood culture or real-time PCR results in Chagas disease patients who received kidney transplants. The real-time PCR presented detection limit of 0.1 parasite equivalent/mL. The time interval between the transplant and sample collection varied from one to 19 years. CONCLUSIONS: No parasites were detected in the evaluated patients. The use of benznidazole and immunosuppressive therapy may have contributed to control the T. cruzi infection. In transplanted patients with Chagas disease, the use of methods such real-time PCR and blood culture can monitor the parasitic load and prevent disease reactivation.

Mitochondrial behavior during nuclear and mitochondrial DNA repair in Trypanosoma cruzi epimastigotes.

Different genotoxic agents can lead to DNA single- and double-strand breaks, base modification and oxidation. As most living organisms, Trypanosoma cruzi is subjected to oxidative stress during its life cycle; thus, DNA repair is essential for parasite survival and establishment of infection. The mitochondrion plays important roles beyond the production of ATP. For example, it is a source of signaling molecules, such as the superoxide anion and H2O2. Since T. cruzi has only one mitochondrion, the integrity of this organelle is pivotal for parasite viability. H2O2 and methyl methanesulfonate cause DNA lesions in T. cruzi that are repaired by different DNA repair pathways. Herein, we evaluate mitochondrial involvement during the repair of nuclear and mitochondrial DNA in T. cruzi epimastigotes incubated with these two genotoxic agents under conditions that induce repairable DNA damage. Overall, in both treatments, an increase in oxygen consumption rates and in mitochondrial H2O2 release was observed, as well as maintenance of ATP levels compared to control. Interestingly, these changes coincided with DNA repair kinetics, suggesting the importance of the mitochondrion for this energy-consuming process.

Synthesis, in vitro and in vivo anti-Trypanosoma cruzi and toxicological activities of nitroaromatic Schiff bases.

Chagas disease is a major health problem not only in Latin America but also in Europe and North America due to the spread of this disease into nonendemic areas. In terms of global burden, this major tropical infection is considered to be one of the most neglected diseases, and there are currently only two available chemotherapies: benznidazole and nifurtimox. Unfortunately, although these chemotherapies are beneficial in the acute phase of the disease, benznidazole and nifurtimox lead to significant side effects, including hepatitis and neurotoxicity. Therefore, the search for and development of more effective, safe and inexpensive anti-Trypanosoma cruzi drugs are required. In this work, a series of 10 nitroaromatic Schiff bases bearing different (nitro) aromatic rings-was synthesized. Subsequently, the in vitro and in vivo anti-T. cruzi activities of the Schiff bases were investigated, as well as the in vivo toxicity and the biological effects. The basic structure of the most promising in vivo Schiff base, 10 would be useful in the synthesis of new compounds for Chagas disease treatment.