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.

New Molecular Markers Distinguishing Fonsecaea Agents of Chromoblastomycosis.

The species belonging to the genus Fonsecaea are the main causative agents of chromoblastomycosis. The invasive potential of Fonsecaea differs significantly among its various sibling species. Moreover, the lack of clarity on the virulence and availability of precise markers to distinguish and detect Fonsecaea species is attributed to the different ways of dissemination and pathogenicity. Therefore, the present study aimed to propose new molecular tools to differentiate between sibling species causing chromoblastomycosis. We used an infection model of chromoblastomycosis in BALB/c to study species-specific molecular markers for the in vivo detection of Fonsecaea species in biological samples. Specific primers based on the CBF5 gene were developed for Fonsecaea pedrosoi, Fonsecaea monophora, Fonsecaea nubica, and Fonsecaea pugnacius. In addition, a padlock probe was designed for F. pugnacius based on ITS sequences. We also assessed the specificity of Fonsecaea species using in silico, in vitro, and in vivo assays. The results showed that markers and probes could effectively discriminate the species in both clinical and environmental samples, enabling bioprospecting of agents of chromoblastomycosis, thereby elucidating the infection route of the disease.