Control de Rhizoctonia solani con extractos de Ovidia andina

New alternatives are needed to control ubiquitous soilborne fungi like Rhizoctonia solani. This work evaluates the activity of extracts from Ovidia andina on this pathogen. Powdered dried leaves and stems were extracted by maceration with dichloromethane (CH2Cl2), methanol and ethanol. An aqueous extract was obtained by decoction, and the hydrodistillation residual water was the aqueous phase after essences production. A strain of R. solani was cultivated on potato dextrose agar supplemented with the extracts, at 1:100 and 1:1000 v/v. The CH2Cl2 extract at 1:100 reduced colony growth (p< 0.0001) and changed hyphal morphology. Five fractions were obtained from the CH2Cl2 extract in a glass column, and TLC analysis showed the presence of coumarins and flavonoids. The CH2Cl2 extract and fractions were diluted in CH2Cl2 or acetone. The efficiency to reduce pathogen growth of fractions 2f and 5f diluted in CH2Cl2 at 1:100 did not differ from the whole extract (p<0.0001). For an in vivo test, beetroot seed balls were incubated in soil infested with R. solani and treated by immersion in the CH2Cl2 extract at 1:100 for different periods of time. As a result, pathogen colonization was diminished by immersion for 120 s and seed germination was normal (p< 0.0001). Additionally, infested soil was treated with the CH2Cl2 extract, and inoculum concentration estimated using beetroot seed balls as baits diminished (p< 0.0001). These results lead us to conclude that O. andina is a source of antifungal components for crop protection against R. solani.Resulta necesario generar alternativas para el control de hongos patógenos de suelo como Rhizoctonia solani. En este trabajo, se evaluó la actividad de extractos de Ovidia andina sobre una cepa del patógeno. Se realizaron extracciones a partir de hojas y tallos secos pulverizados, macerados con diclorometano (CH2Cl2), metanol y etanol. Se obtuvo un extracto acuoso por decocción y aguas residuales consistentes en la fase acuosa luego de la producción de esencias. Se cultivó una cepa de R. solani en agar papa glucosa suplementado con los extractos diluidos 1:100 o 1:1000 v/v. El extracto CH2Cl2 1:100 redujo el crecimiento de las colonias (p< 0,0001) y alteró la morfología de las hifas. Se obtuvieron 5 fracciones del extracto CH2Cl2 en una columna de vidrio y mediante TLC se detectó la presencia de cumarinas y flavonoides. Posteriormente, el extracto CH2Cl2 y sus fracciones se diluyeron en CH2Cl2 o acetona. La eficiencia de las fracciones 2f y 5f diluidas CH2Cl2 1:100 para reducir el crecimiento fúngico no difirió de la del extracto completo (p<0,0001). En un experimento in vivo, se incubaron glomérulos de remolacha en suelo infestado con R. solani y se sumergieron en el extracto CH2Cl2 1:100 durante tiempos variables. La colonización fúngica disminuyó mediante la inmersión durante 120 segundos, sin afectar la germinación (p< 0,0001). Adicionalmente, se trató suelo infestado con el extracto CH2Cl2 y disminuyó la concentración de inóculo del patógeno estimada utilizando glomérulos de remolacha como trampas (p< 0,0001). Estos resultados permiten concluir que O. andina es una fuente de componentes antifúngicos para la protección vegetal contra R. solani.Fil: Tito Mansilla, Javier. Universidad Nacional de San MartínFil: Tarcaya, Verónica P.. Universidad de Buenos AiresFil: Cufre, Ingrid M.. Universidad de Buenos AiresFil: Fabrizio, María C.. Universidad de Buenos Aires. Facultad de AgronomíaFil: Wright, Eduardo R.. Universidad de Buenos Aires. Facultad de AgronomíaFil: Broussalis, Adriana M.. Universidad de Buenos AiresFil: Rivera, Marta C.. Universidad de Buenos Aires. Facultad de Agronomí

Successful alternative treatment of extensively drug-resistant tuberculosis in Argentina with a combination of linezolid, moxifloxacin and thioridazine.

Item does not contain fulltextOBJECTIVES: Current drug choices to treat extensively drug-resistant (XDR) tuberculosis (TB) are scarce; therefore, information on the safety, tolerability and efficacy of alternative regimens is of utmost importance. The aim of this study was to describe the management, drug adverse effects and outcome of alternative combined treatment in a series of XDR-TB patients. PATIENTS AND METHODS: A retrospective study was performed on 17 non-AIDS, pulmonary adult patients with XDR-TB admitted to a referral treatment centre for infectious diseases in Buenos Aires from 2002 through 2008. Drug susceptibility testing was performed under regular proficiency testing and confirmed at the national TB reference laboratory. RESULTS: Linezolid was included in the drug regimens of all patients; moxifloxacin and/or thioridazine were included in the regimens of 14 patients. Clinically tractable drug adverse effects were observed in nine patients, the most frequent being haematological disorders and neurotoxicity. In two patients, thioridazine was discontinued. Negative culture conversion was achieved in 15 patients, 11 completed treatment meeting cure criteria, 4 are still on follow-up with good evolution, 1 defaulted treatment and 1 was lost to follow-up. CONCLUSIONS: The combination of linezolid, moxifloxacin and thioridazine is recommended for compassionate use in specialized centres with expertise in the management of XDR-TB.1 februari 201

Control of Rhizoctonia solani with extracts from Ovidia andina = Control de Rhizoctonia solani con extractos de Ovidia andina

New alternatives are needed to control ubiquitous soilborne fungi like Rhizoctonia solani. This work evaluates the activity of extracts from Ovidia andina on this pathogen. Powdered dried leaves and stems were extracted by maceration with dichloromethane (CH2Cl2), methanol and ethanol. An aqueous extract was obtained by decoction, and the hydrodistillation residual water was the aqueous phase after essences production. A strain of R. solani was cultivated on potato dextrose agar supplemented with the extracts, at 1:100 and 1:1000 v/v. The CH2Cl2 extract at 1:100 reduced colony growth (p< 0.0001) and changed hyphal morphology. Five fractions were obtained from the CH2Cl2 extract in a glass column, and TLC analysis showed the presence of coumarins and flavonoids. The CH2Cl2 extract and fractions were diluted in CH2Cl2 or acetone. The efficiency to reduce pathogen growth of fractions 2f and 5f diluted in CH2Cl2 at 1:100 did not differ from the whole extract (p<0.0001). For an in vivo test, beetroot seed balls were incubated in soil infested with R. solani and treated by immersion in the CH2Cl2 extract at 1:100 for different periods of time. As a result, pathogen colonization was diminished by immersion for 120 s and seed germination was normal (p< 0.0001). Additionally, infested soil was treated with the CH2Cl2 extract, and inoculum concentration estimated using beetroot seed balls as baits diminished (p< 0.0001). These results lead us to conclude that O. andina is a source of antifungal components for crop protection against R. solani.Resulta necesario generar alternativas para el control de hongos patógenos de suelo como Rhizoctonia solani. En este trabajo, se evaluó la actividad de extractos de Ovidia andina sobre una cepa del patógeno. Se realizaron extracciones a partir de hojas y tallos secos pulverizados, macerados con diclorometano (CH2Cl2), metanol y etanol. Se obtuvo un extracto acuoso por decocción y aguas residuales consistentes en la fase acuosa luego de la producción de esencias. Se cultivó una cepa de R. solani en agar papa glucosa suplementado con los extractos diluidos 1:100 o 1:1000 v/v. El extracto CH2Cl2 1:100 redujo el crecimiento de las colonias (p< 0,0001) y alteró la morfología de las hifas. Se obtuvieron 5 fracciones del extracto CH2Cl2 en una columna de vidrio y mediante TLC se detectó la presencia de cumarinas y flavonoides. Posteriormente, el extracto CH2Cl2 y sus fracciones se diluyeron en CH2Cl2 o acetona. La eficiencia de las fracciones 2f y 5f diluidas CH2Cl2 1:100 para reducir el crecimiento fúngico no difirió de la del extracto completo (p<0,0001). En un experimento in vivo, se incubaron glomérulos de remolacha en suelo infestado con R. solani y se sumergieron en el extracto CH2Cl2 1:100 durante tiempos variables. La colonización fúngica disminuyó mediante la inmersión durante 120 segundos, sin afectar la germinación (p< 0,0001). Adicionalmente, se trató suelo infestado con el extracto CH2Cl2 y disminuyó la concentración de inóculo del patógeno estimada utilizando glomérulos de remolacha como trampas (p< 0,0001). Estos resultados permiten concluir que O. andina es una fuente de componentes antifúngicos para la protección vegetal contra R. solani.Instituto de FloriculturaFil: Mansilla, Javier Tito. Universidad Nacional de San Martín. Posgrado; ArgentinaFil: Tarcaya, Verónica P. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Cufre, Ingrid M. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Fabrizio, María del Carmen. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Wright, Eduardo Roberto. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Broussalis, Adriana M. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Rivera, Marta Carolina. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; Argentin