In Vitro and In Vivo Effect of Peptides Derived from 14-3-3 Paracoccidioides spp. Protein.

BACKGROUND: Paracoccidioidomycosis (PCM) is a chronic disease that causes sequelae and requires prolonged treatment; therefore, new therapeutic approaches are necessary. In view of this, three peptides from Paracoccidioides brasiliensis 14-3-3 protein were selected based on its immunogenicity and therapeutic potential. METHODS: The in vitro antifungal activity and cytotoxicity of the 14-3-3 peptides were evaluated. The influence of the peptides in immunological and survival aspects was evaluated in vivo, using Galleria mellonella and the expression of antimicrobial peptide genes in Caenorhabditis elegans. RESULTS: None of the peptides were toxic to HaCaT (skin keratinocyte), MRC-5 (lung fibroblast), and A549 (pneumocyte) cell lines, and only P1 exhibited antifungal activity against Paracoccidioides spp. The peptides could induce an immune response in G. mellonella. Moreover, the peptides caused a delay in the death of Paracoccidioides spp. infected larvae. Regarding C. elegans, the three peptides were able to increase the expression of the antimicrobial peptides. These peptides had essential effects on different aspects of Paracoccidioides spp. infection showing potential for a therapeutic vaccine. Future studies using mammalian methods are necessary to validate our findings.

In Vitro and In Vivo Inhibitory Activity of Limonene against Different Isolates of Candida spp.

Commensal yeast from the genus Candida is part of the healthy human microbiota. In some cases, Candida spp. dysbiosis can result in candidiasis, the symptoms of which may vary from mild localized rashes to severe disseminated infections. The most prevalent treatments against candidiasis involve fluconazole, itraconazole, miconazole, and caspofungin. Moreover, amphotericin B associated with prolonged azole administration is utilized to control severe cases. Currently, numerous guidelines recommend echinocandins to treat invasive candidiasis. However, resistance to these antifungal drugs has increased dramatically over recent years. Considering this situation, new therapeutic alternatives should be studied to control candidiasis, which has become a major medical concern. Limonene belongs to the group of terpene molecules, known for their pharmacological properties. In this study, we evaluated in vitro the limonene concentration capable of inhibiting the growth of yeast from the genus Candida susceptible or resistant to antifungal drugs and its capacity to induce fungal damage. In addition, intravaginal fungal infection assays using a murine model infected by Candida albicans were carried out and the fungal burden, histopathology, and scanning electron microscopy were evaluated. All of our results suggest that limonene may play a protective role against the infection process by yeast from the genus Candida.

Molecular detection of Histoplasma capsulatum indoors: A public health approach / Detección molecular de Histoplasma capsulatum en interiores: un enfoque de salud pública

Background: Histoplasmosis, caused by the dimorphic fungus Histoplasma capsulatum, represents an important public health problem, especially in urban environments where bats and humans cohabit indoors. Aims: To detect the presence of H. capsulatum indoors, using samples of bat droppings collected in roost sites inside houses. Methods:A Real-Time TaqMan PCR assay targeting the ITS1 region of the ribosomal NA of H. capsulatum was carried out. Results: Fifty-nine sampling points in the municipality of São Paulo were inspected, all of them located at inhabited places. H. capsulatum was isolated from nine samples. Conclusions: The rapid identification and monitoring of sites where the fungus is present may contribute to make a more reliable database of H. capsulatum distribution

Antecedentes: La histoplasmosis, causada por el hongo dimorfo Histoplasma capsulatum, representa un importante problema de salud pública, especialmente en los entornos urbanos donde los murciélagos y los humanos conviven en los espacios interiores. Objetivos: Detectar la presencia de H. capsulatum en interiores mediante muestras de excrementos de murciélagos recogidas en sitios de reposo de estos animales dentro de las casas. Métodos: Se llevó a cabo un ensayo de PCR TaqMan(R) en tiempo real dirigido a la región ITS1 del ADN ribosómico de H. capsulatum. Resultados: Se muestrearon 59 puntos en el municipio de São Paulo, todos ubicados en lugares habitados. H. capsulatum se aisló en nueve de estos lugares. Conclusiones: Una rápida identificación y control de los sitios donde se encuentra H. capsulatum contribuiría a la creación de una base de datos más sólida en lo referente a la distribución de este hongo

Unravelling the nature of the spongy dark material in aged Turkevich gold nanoparticles colloidal solutions by CytoViva® dark-field imaging and HRTEM analysis.

Turkevich gold nanoparticles colloidal solutions undergo further changes after ageing for several weeks or months, and in most cases a spongy dark material can be observed suspended in the red solution. CytoViva® dark-field microscopy images and high resolution transmission electron micrographys (HRTEM) of the strange body played a central role and revealed a fibrous structure, consistent with cellulose, as commonly found in the cell-walls of many fungi. Surprisingly, the interior of the fibers are filled with gold nanoparticles, responsible for the high contrasting images obtained in this work. The fungi were replicated in the laboratory, characterized by Infrared Microscopy (FTIR) and revealed an ability to grow in gold-citrate media, even in dark and anaerobical conditions.