Herramientas didácticas para la formación agroforestal

Como resultado de los trabajos de investigación por más de diez años del grupo Plan de Investigación para el Fortalecimiento Integral de las Comunidades – PIFIL, en este libro se evidencias las lecciones aprendidas en el diseño y uso de herramientas didácticas para la formación de comunidades rurales, destacándose el material didáctico manual y digital agroforestal como innovadores en la implementación de las tecnologías de la información y la comunicación – TIC que facilitan los procesos de enseñanza aprendizaje para la aprehensión del conocimiento, consolidación del tejido social; fortalecimiento de la cohesión y congestión que coadyuvan con el mejoramiento de los medios de vida y uso sustentable de los recursos naturales

Silver nanoparticles as an antimicrobial agent of Tricophyton rubrum

Resistance to antimicrobial agents, such as amphotericin B, fluconazole, itraconazole, and voriconazole, by pathogenic bacteria and fungi has been increasing at an alarming rate and has become a serious problem. Microorganisms, such as bacteria, moulds, yeasts, and viruses are often pathogenic to humans. There is a pressing need to search for new antimicrobial agents. Amongst inorganic antimicrobial agents, silver has been employed most widely since ancient times to fight infections. The antimicrobial activities of silver, silver ions, and silver compounds are well known Fungi can be employed for biosynthesis of nanoparticles hence avoiding the use of hazardous chemicals for synthesis. However, the effects of mycological synthesized silver nanoparticles against fungal dermatophytes are not well understod. In this work were used inorganic and biogenic routes for the synthesis of silver nanoparticles. In the biogenic route, extracts from Aspergillus oryzae and Penicillium chrysogenum were used. In the inorganic route glucose was used as the reducing agent and polyvinylpyrrolidone as the stabilizer. The nanoparticles were characterized by various techniques. Biogenic nanoparticles from A. ozyzae and P. chrysogenum showed an average size from 19-51 nm to 51-85 nm, respectively. Nanoparticles synthesized by inorganic route had a mean size of 74 nm as determined by Dynamic Light Scattering. The antimicrobial potential activity was tested against strains of Tricophyton rubrum and the silver nanoparticles from P. chrysogenum had antimicrobial effects against T. rubrum strains. The synthesis parameters in future studies should be studied to take full advantage of the potentail for filamentous fungi to synthesise silver nanoparticles

MALDI-TOF ICMS: capability, potentiality and limits in the fast identification of Trichophyton rubrum from clinical cases occurrence in Portuguese health centres

Objective: Trichophyton rubrum is presently the most common worldwide pathogen causing dermatophytoses such as tinea corporis, tinea capitis, tinea pedis, and onychomycosis [1]. The main aim of the present work was assess MALDI-TOF ICMS as a fast and reliable technique in the identification of T. rubrum from clinical cases occurrence in the Portuguese health centres, and evaluates the potentialities and limits of this new microbial identification technique on the taxonomy of these infectious dermatophytes. Methods: Fungi were grown for 10 days in solid medium (SDA, Sabouraud Dextrose Agar) and then the mycelia were direct transferred from the SDA plate to the MALDI stainless steel template and mixed with 1 ml MALDI matrix solution (75 mg/ml 2,5-dihydroxybenzoic acid in ethanol/water/acetonitrile [1:1:1] with 0.03% trifluoroacetic acid). The sample mixtures were air dried at room temperature. The analyses were performed in our laboratory on an Axima LNR system (Kratos Analytical, Shimadzu, Manchester, UK) equipped with a nitrogen laser (337 nm). The mass range from m/z = 2,000 to 20,000 Da was recorded. Escherichia coli strain DH5a with known mass values of ribosomal proteins was used for external calibration. The fungi classification was performed on the SARAMIS software (AnagnosTec mbH, Potsdam- Golm, Germany). Molecular biology was used when appropriated with PCR based-technology. The presence of a 203-bp PCR product confirmed T. rubrum identification. Results: All strains were accurately and consistently identified as T. rubrum by MALDI-TOF ICMS combined to SARAMIS database analysis. Spectral mass analysis proven to be a rapid method since the analysis took only a few minutes to perform with the benefit of any laborious sample preparation procedures or any expensive chemical reagent was needed. Conclusions: The fungal spectral analysis by MALDI-TOF ICMS was as good as molecular biology in order to identify T. rubrum but much faster and cheaper

Identification of clinical isolates Trichophyton rubrum using a rapid and accurate mass spectral analysis (MALDI‐TOF ICMS)

condition called “ringworm” in man. The affinity for keratinized tissues by dermatophytes, implies in most of the cases, that the infection remains restricted to the nonliving cornified layers of the skin, nails, and hair [1]. Among dermatophytes, the species Trichophyton rubrum is of particular clinical interest for man because is the most common agent of human dermatophytoses. Macro and micro‐morphological examination combined to physiological analysis of primary isolates grown in selective culture media are still the most used methods in routine laboratory. Besides their low specificity, an accurate diagnosis may take 3 to 4 weeks to be achieved Modern identification methods involve molecular biology by using PCR technology based on differential sequence elements. It is gradually becoming clearer that microbial identification and authentication requires a polyphasic approach to generate quality data which are accurate and useful [2]. Microbial mass spectral analysis has been progressively more incorporated to the polyphasic approach to improve the accuracy of the microbial identification issue. Matrix Assisted Laser Desorption Ionization Time of Flight Intact Cell Mass Spectroscopy (MALDI‐TOF ICMS) is becoming an alternative to DNA‐dependent methods so it has been already successfully applied to the rapid identification and classification of microorganisms [3].The aim of this work was to test the applicability of MALDI‐TOF ICMS for identifying clinical isolates of T. rubrum. In this study twenty clinical isolates of T. rubrum were grown on Sabouraud culture medium. Plates were incubated for 7 days at 25 ºC. All the isolates were identified both macroscopically and microscopically. From the same plate, a tiny sample (about 50 mg) was transferred to stainless steel templates. A 0.5 ml of dihydroxy‐benzoic acid (DHB) matrix solution was added to the sample and air dried. Peak lists of individual samples were compared with the superspectra database generating a ranked list of matching spectra from SARAMIS software. All strains were accurately and consistently identified as T. rubrum by MALDI‐TOF ICMS combined to SARAMIS database analysis. Spectral mass analysis proven to be a rapid method, as the analysis took only a few minutes to perform with the benefit of any laborious sample preparation procedures or any expensive chemical reagent was needed