Antifungal activity of extracts from Atacama Desert fungi against Paracoccidioides brasiliensis and identification of Aspergillus felis as a promising source of natural bioactive compounds

Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values ≤ 125.0 μg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 μg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 μg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity.

Analysis of the LRRK2 p.G2019S mutation in Colombian Parkinson’s Disease Patients

Introduction: Mutations in the leucine-rich repeat kinase 2 gene (LRRK2 or Dardarin) are considered to be a common cause of autosomal dominant and sporadic Parkinson´s disease, but the prevalence of these mutations varies among populations. Objective: To analyzed the frequency of the LRRK2 p.G2019S mutation (c.6055G>A transition) in a sample of Colombian patients. Methods: In the present study we have analyzed the frequency of the LRRK2 p.G2019S mutation in 154 patients with familial or sporadic Parkinson Disease, including early and late onset patients, and 162 normal controls. Results: Our results show occurrence of this mutation in two cases (2/154, 1.3%) with classical Parkinson´s signs, and one completely asymptomatic control (1/162, 0.6%). Conclusion: The p.G2019S mutation is not an important causal factor of Parkinson Disease in Colombia having similar frequencies to those reported in other Latin American populations.