Molecular Identification and Antimicrobial Activity of Foliar Endophytic Fungi on the Brazilian Pepper Tree (Schinus terebinthifolius) Reveal New Species of Diaporthe.

The presence of endophytes promotes the biosynthesis of secondary plant metabolites. In this study, endophytic fungi were isolated from Schinus terebinthifolius to investigate their diversity and antimicrobial activity. A total of 272 endophytic fungi was obtained. These belonged to nine different genera: Alternaria, Colletotrichum, Diaporthe, Epicoccum, Fusarium, Pestalotiopsis, Phyllosticta, Xylaria, and Cryptococcus. Notably, Diaporthe foliorum was introduced as a new species, with accompanying morphological descriptions, illustrations, and a multigene phylogenetic analysis (using ITS, TEF1, TUB, HIS, and CAL). Among the 26 fungal morphotypes evaluated for antimicrobial activity, five strains had inhibitory effects against pathogenic microorganisms. Xylaria allantoidea CMRP1424 extracts showed antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Diaporthe terebinthifolii CMRP1430 and CMRP1436 showed antimicrobial activity against E. coli, P. aeruginosa, S. aureus, and C. albicans. Meanwhile, D. foliorum CMRP1321 and D. malorum CMRP1438 extracts inhibited C. albicans alone. Three classes of chemical compounds were identified in D. foliorum CMRP1438 extracts: ferric chloride, potassium hydroxide, and vanillin-sulfuric acid. In conclusion, the endophytic isolates were able to produce bioactive agents with pharmaceutical potential as antibacterial and antifungal agents. As such, they may provide fresh leads in the search for new, biological sources of drug therapies.

Geographic and temporal genetic patterns of Aedes aegypti populations in Rio de Janeiro, Brazil.

Rio de Janeiro is considered as the most important entry point for dengue viruses in Brazil. Using isoenzyme markers, we investigated the genetic structure of the mosquito vector Aedes aegypti sampled at three-month intervals in 14 districts in Rio de Janeiro from December 2002 to December 2003. We detected high levels of genetic differentiation (i.e. high F(ST) values and significant P values), which tended to persist throughout the year. The species does not take advantage of routes and railways to disperse. Genetic structuring was higher in the rainy season, suggesting low dispersion of Ae. aegypti at this time of year when all dengue epidemics have been reported in the city.