The first line treatment for Chagas disease, a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi, involves administration of benznidazole (Bzn). Bzn is a 2-nitroimidazole pro-drug which requires nitroreduction to become active, although its mode of action is not fully understood. In the present work we used a non-targeted MS-based metabolomics approach to study the metabolic response of T. cruzi to Bzn. Parasites treated with Bzn were minimally altered compared to untreated trypanosomes, although the redox active thiols trypanothione, homotrypanothione and cysteine were significantly diminished in abundance post-treatment. In addition, multiple Bzn-derived metabolites were detected after treatment. These metabolites included reduction products, fragments and covalent adducts of reduced Bzn linked to each of the major low molecular weight thiols: trypanothione, glutathione, γ-glutamylcysteine, glutathionylspermidine, cysteine and ovothiol A. Bzn products known to be generated in vitro by the unusual trypanosomal nitroreductase, TcNTRI, were found within the parasites, but low molecular weight adducts of glyoxal, a proposed toxic end-product of NTRI Bzn metabolism, were not detected. Our data is indicative of a major role of the thiol binding capacity of Bzn reduction products in the mechanism of Bzn toxicity against T. cruzi. The unicellular parasite Trypanosoma cruzi infects humans, leading to Chagas disease, endemic in Central and South America and responsible for 13,000 annual deaths. Only two drugs have proven effective against Chagas, nifurtimox and benznidazole (Bzn). Bzn has the best safety and efficacy profiles and is thus used as first line treatment. Bzn is a pro-drug, and possesses a nitro group which needs to be enzymatically reduced within the parasite to become active. We have investigated for the first time, by means of mass spectrometry based metabolomics, the global changes to small metabolites that occur once Bzn enters the parasite. A decrease in the levels of several thiols, including cysteine and trypanothione, and an increase in gamma-glutamyl containing dipeptides were observed after treatment. Reduced metabolites of Bzn were also detected, together with numerous covalent conjugates of the drug combined with low molecular weight thiols and some non-thiol metabolites. Overall, Bzn treatment primarily affects thiol containing molecules in T. cruzi, and this interference with thiol metabolism contributes to the drug's mode of action.

During a survey of carotenogenic yeasts from cold and oligotrophic environments in Patagonia, several yeasts of the genus Dioszegia (Tremellales, Agaricomycotina) were detected, including three strains that could not be assigned to any known taxa. Analyses of internal transcribed spacer and D1/D2 regions of the large subunit rRNA gene showed these strains are conspecific with several other strains found in the Italian Alps and in Antarctica soil. Phylogenetic analyses showed that 19 of these strains represent a novel yeast species of the genus Dioszegia. The name Dioszegia patagonica sp. nov. is proposed to accommodate these strains and CRUB 1147T (UFMG 195T=CBMAI 1564T=DBVPG 10618T=CBS 14901T; MycoBank MB 819782) was designated as the type strain. This Dioszegia species accumulates biotechnologically valuable compounds such as carotenoid pigments and mycosporines.

The discovery that trypanosomatids, unicellular organisms of the order Kinetoplastida, are capable of synthesizing prostaglandins raised questions about the role of these molecules during parasitic infections. Multiple studies indicate that prostaglandins could be related to the infection processes and pathogenesis in trypanosomatids. This work aimed to unveil the role of the prostaglandin F₂α synthase TcOYE in the establishment of Trypanosoma cruzi infection, the causative agent of Chagas disease. This chronic disease affects several million people in Latin America causing high morbidity and mortality. Here, we propose a prokaryotic evolutionary origin for TcOYE, and then we used in vitro and in vivo experiments to show that T. cruzi prostaglandin F_2α synthase plays an important role in modulating the infection process. TcOYE overexpressing parasites were less able to complete the infective cycle in cell culture infections and increased cardiac tissue parasitic load in infected mice. Additionally, parasites overexpressing the enzyme increased PGF₂α synthesis from arachidonic acid. Finally, an increase in benznidazole and nifurtimox susceptibility in TcOYE overexpressing parasites showed its participation in activating the currently anti-chagasic drugs, which added to its observed ability to confer resistance to hydrogen peroxide, highlights the relevance of this enzyme in multiple events including host–parasite interaction.

Twenty-one psychrophilic yeast isolates related to theCamptobasidiaceaefamily in theMicrobotryomycetesclass were obtained from ice collected from cold environments worldwide. A new psychrophilic species from the recently described genusCryolevonia, Cryolevania giraudoaeis proposed to accommodate 18 isolates from Patagonia (Argentina) and Antarctica (holotype CRUB 2086^T). In addition, a new psychrophilic species in the genusCamptobasidiumis described asCamptobasidium gelussp. nov. (holotype CBS 8941^T), based on three isolates from glacial ice in the Russel glacier (Greenland ice sheet) and Antarctica. The strict psychrophilic profile is the salient feature of both novel species.