No abstract

Mucorales are resistant to most antifungals. Mucormycosis associated mortality is unacceptable and new treatment approaches are needed. The objectives of this work were (i) to evaluate the nature and intensity of the in vitro effect of three drugs combinations which included voriconazole (plus amphotericin B, posaconazole and caspofungin) against 25 strains of six different Mucorales species; (ii) to evaluate a Galleria mellonella mucormycosis model; and (iii) to establish if any in vitro–in vivo correlation exists. As expected, amphotericin B and posaconazole were the most active drugs when tested alone. However, species-specific differences were found. The ΣFICs varied according to the used combination. Only five strains showed synergism when voriconazole was combined with posaconazole and three strains when combined with amphotericin B. Microscopic hyphae alteration were observed for some isolates when confronted against drugs combinations. Using a Galleria mellonella mucormycosis model, better survival was seen in voriconazole plus amphotericin B and plus caspofungin combined treatments when compared with AMB alone for R. microsporus. These survival improvements were obtained using a 32-fold lower amphotericin B doses when combined with VRC than when treated with the polyene alone. These lower antifungal doses emulate the antifungal concentrations where the microscopic hyphae alterations were seen.

No abstract

In order to evaluate the effect of Azospirillum brasilense and mycorrhizal fungi in the soil on the nutrition of the yacon crop (Smallanthus sonchifolius [(Poeppig & Endlicher) H. Robinson]), determinations of agronomic parameters and the health status of the plants were carried out, under field conditions. The tests were carried out, at the time of the implantation of the culture: the propagules were inoculated with A. brasilense and with native mycorrhizal fungi, generating four treatments including the control and the co-inoculation of the consortium of the microorganisms under study (T0: control without inoculation; T1: inoculation with native A. brasilense; T2: inoculation with native mycorrhizal fungi and T3: joint inoculation with A. brasilense and native mycorrhizal fungi). The results indicate that co-inoculation with A. brasilense and with native mycorrhizal fungi, increased significantly the growth of plants in height, leaf area, biomass, dry matter and yields, in field production. It was determined that the application of the selected microorganisms has a promoting effect of plant growth, increasing growth and productivity of the cultivation of yacon.

Muestras de suelo fueron colectadas en la provincia de Catamarca en lotes cultivados con topinambur (Helianthus tuberosus L.) al momento de implantación y cosecha durante cuatro ciclos agrícolas. Los tubérculos fueron tratados con Azospirillum brasilense, hongos micorrícicos o ambos microorganismos. Tubérculos correspondientes a los testigos no se inocularon con estos microorganismos. Se determinó la Actividad Biológica Total (ABT) por Hidrólisis del Diacetato de Fluoresceína a las muestras colectadas. La ABT del suelo fue afectada por los diferentes tratamientos del cultivo. La inoculación microbiana elevó la ABT de los suelos estudiados, difiriendo estadísticamente con los testigos. También se observaron diferencias signifi cativas entre la ABT de los suelos al inicio del cultivo con los valores registrados a la cosecha de los mismos. La inoculación de tubérculos de topinambur con A. brasilense y hongos micorrícicos afecta la ABT de los suelos cultivados.