Chagas disease, a neglected illness, affects nearly 12-14 million people in endemic areas of Latin America. Although the occurrence of acute cases sharply has declined due to Southern Cone Initiative efforts to control vector transmission, there still remain serious challenges, including the maintenance of sustainable public policies for Chagas disease control and the urgent need for better drugs to treat chagasic patients. Since the introduction of benznidazole and nifurtimox approximately 40 years ago, many natural and synthetic compounds have been assayed against Trypanosoma cruzi, yet only a few compounds have advanced to clinical trials. This reflects, at least in part, the lack of consensus regarding appropriate in vitro and in vivo screening protocols as well as the lack of biomarkers for treating parasitaemia. The development of more effective drugs requires (i) the identification and validation of parasite targets, (ii) compounds to be screened against the targets or the whole parasite and (iii) a panel of minimum standardised procedures to advance leading compounds to clinical trials. This third aim was the topic of the workshop entitled Experimental Models in Drug Screening and Development for Chagas Disease, held in Rio de Janeiro, Brazil, on the 25th and 26th of November 2008 by the Fiocruz Program for Research and Technological Development on Chagas Disease and Drugs for Neglected Diseases Initiative. During the meeting, the minimum steps, requirements and decision gates for the determination of the efficacy of novel drugs for T. cruzi control were evaluated by interdisciplinary experts and an in vitro and in vivo flowchart was designed to serve as a general and standardised protocol for screening potential drugs for the treatment of Chagas disease

No abstract

In Antarctica, microorganisms dominate food chains in several different pristine ecosystems. In these ecosystems, fungi occur as two known basic forms (i) filamentous fungi and (ii) yeasts, which display colonies with different morphologies and colours (Fig. 1.1). Such colonies demonstrate a high degree of genetic plasticity that allows them to survive under extreme conditions of low temperatures, high UV irradiation, freeze-thaw cycles, different pH levels, strong winds, dehydration, osmotic stress, and low nutrient concentrations (Fell et al. 2006). The fungal assemblages of Antarctica include taxa that belong to the major fungal groups, which were reported by Kirk et al. (2008) to be Ascomycota, Basidiomycota, traditional Zygomycota, Chytridiomycota, and Glomeromycota;

Molecular biology techniques were used to identify 218 fungi from soil samples collected from four islands of Antarctica. These consisted of 22 taxa of 15 different genera belonging to the Zygomycota, Ascomycota, and Basidiomycota. Mortierella, Antarctomyces, Pseudogymnoascus, and Penicillium were the most frequently isolated genera and Penicillium tardochrysogenum, Penicillium verrucosus, Goffeauzyma gilvescens, and Mortierella sp. 2 the most abundant taxa. All fungal isolates were cultivated using solid-state fermentation to obtain their crude extracts. Pseudogymnoascus destructans, Mortierella parvispora, and Penicillium chrysogenum displayed antiparasitic activities, whilst extracts of P. destructans, Mortierella amoeboidea, Mortierella sp. 3, and P. tardochrysogenum showed herbicidal activities. Reported as pathogenic for bats, different isolates of P. destructans exhibited trypanocidal activities and herbicidal activity, and may be a source of bioactive molecules to be considered for chemotherapy against neglected tropical diseases. The abundant presence of P. destructans in soils of the four islands gives evidence supporting that soils in the Antarctic Peninsula constitute a natural source of strains of this genus, including some P. destructans strains that are phylogenetically close to those that infect bats in North America and Europe/Palearctic Asia.

No abstract