Maíz Bt : seguimiento de la resistencia de Sesamia nonagrioides (Lepidoptera: Noctuidae) y Ostrinia nubilalis (Lepidoptera: Crambidae) y efectos en artrópodos depredadores

Desde 1999 hasta 2002 se realizó un seguimiento de la resistencia de S. nonagrioides y O. nubilalis al maíz Bt var. Compa CB (derivada del evento 176, que expresa la toxina Cry1Ab) en zonas representativas del cultivo del maíz en España. Para dichas poblaciones se calculó la concentración de Cry1Ab que mata al 50% de la población (CL50) y se comparó en el tiempo para determinar cambios en la susceptibilidad. No se observó una tendencia gradual hacia mayores niveles de tolerancia, lo que sugiere que los ligeros cambios en la susceptibilidad detectados son debidos a la variabilidad existente en poblaciones naturales de S. nonagrioides y O. nubilalis y no el resultado de la selección de resistencia. Asimismo, se realizaron dos selecciones consecutivas de resistencia en laboratorio para cada especie, sometiendo a poblaciones de S. nonagrioides y O. nubilalis a dosis crecientes de la toxina Cry1Ab durante 8 generaciones. El resultado de estas selecciones fue un aumento de tolerancia de 2 y 21 veces más que la población control en sendas selecciones de S. nonagrioides y de 6 y 10 veces en las selecciones de O. nubilalis. Esto sugiere que el potencial para desarrollar niveles bajos o moderados de tolerancia a la toxina Cry1Ab puede ser relativamente común entre las poblaciones españolas de taladros del maíz. Finalmente, ninguna de las larvas recogidas en campo o seleccionadas en laboratorio fue capaz de sobrevivir en maíz Bt.Por otro lado, se realizó un estudio de la genética poblacional de S. nonagrioides mediante la técnica de RAPD-PCR, ya que el conocimiento de aquélla es importante para aplicar estrategias de manejo de la resistencia adecuadas. Se analizaron dos poblaciones del valle del Ebro, dos de la zona centro de la Península y dos de Badajoz. Los índices de similitud y las distancias genéticas calculadas indican poca diferenciación entre las seis poblaciones. La tasa efectiva de migración (Nm), calculada como estima del flujo génico entre las poblaciones estudiadas, fue mayor que 2; valor que se considera suficiente para impedir la diferenciación genética entre poblaciones.Por último, se estudiaron los artrópodos depredadores de un campo comercial de maíz situado al sureste de la Comunidad de Madrid durante tres años (de 2000 a 2002) desde mediados de junio hasta finales de septiembre. Se compararon efectos en la abundancia de depredadores presentes en la planta mediante conteo visual y en el suelo mediante trampas de gravedad en parcelas de maíz Bt (var. Compa CB), maíz no Bt (var. Dracma) sin tratamiento insecticida y maíz no Bt pildorado con imidacloprid. Del mismo modo, se compararon los efectos de estos tres tratamientos en la riqueza y diversidad de especies de carábidos y arañas terrestres. El 94% de los depredadores encontrados en el muestreo visual se compuso de: arañas, dos especies del género Orius, Stethorus punctillum y Chrysoperla carnea; el 95% de los depredadores capturados en trampas de gravedad fueron arañas, carábidos y estafilínidos. Todos ellos son depredadores generalistas, excepto S. punctillum, que es depredador especialista de ácaros fitófagos. En cuanto a la abundancia de depredadores, sólo los estafilínidos vieron disminuida significativamente su abundancia en el tratamiento de maíz Bt, aunque estas diferencias se concentraron en una fecha concreta del muestreo en los años 2000 y 2002. Los índices de riqueza y diversidad de las comunidades de arañas y carábidos terrestres no variaron significativamente entre tratamientos.Desde 1999 hasta 2002 se realizó un seguimiento de la resistencia de S. nonagrioides y O. nubilalis al maíz Bt var. Compa CB (derivada del evento 176, que expresa la toxina Cry1Ab) en zonas representativas del cultivo del maíz en España. Para dichas poblaciones se calculó la concentración de Cry1Ab que mata al 50% de la población (CL50) y se comparó en el tiempo para determinar cambios en la susceptibilidad. No se observó una tendencia gradual hacia mayores niveles de tolerancia, lo que sugiere que los ligeros cambios en la susceptibilidad detectados son debidos a la variabilidad existente en poblaciones naturales de S. nonagrioides y O. nubilalis y no el resultado de la selección de resistencia. Asimismo, se realizaron dos selecciones consecutivas de resistencia en laboratorio para cada especie, sometiendo a poblaciones de S. nonagrioides y O. nubilalis a dosis crecientes de la toxina Cry1Ab durante 8 generaciones. El resultado de estas selecciones fue un aumento de tolerancia de 2 y 21 veces más que la población control en sendas selecciones de S. nonagrioides y de 6 y 10 veces en las selecciones de O. nubilalis. Esto sugiere que el potencial para desarrollar niveles bajos o moderados de tolerancia a la toxina Cry1Ab puede ser relativamente común entre las poblaciones españolas de taladros del maíz. Finalmente, ninguna de las larvas recogidas en campo o seleccionadas en laboratorio fue capaz de sobrevivir en maíz Bt.Por otro lado, se realizó un estudio de la genética poblacional de S. nonagrioides mediante la técnica de RAPD-PCR, ya que el conocimiento de aquélla es importante para aplicar estrategias de manejo de la resistencia adecuadas. Se analizaron dos poblaciones del valle del Ebro, dos de la zona centro de la Península y dos de Badajoz. Los índices de similitud y las distancias genéticas calculadas indican poca diferenciación entre las seis poblaciones. La tasa efectiva de migración (Nm), calculada como estima del flujo génico entre las poblaciones estudiadas, fue mayor que 2; valor que se considera suficiente para impedir la diferenciación genética entre poblaciones.Por último, se estudiaron los artrópodos depredadores de un campo comercial de maíz situado al sureste de la Comunidad de Madrid durante tres años (de 2000 a 2002) desde mediados de junio hasta finales de septiembre. Se compararon efectos en la abundancia de depredadores presentes en la planta mediante conteo visual y en el suelo mediante trampas de gravedad en parcelas de maíz Bt (var. Compa CB), maíz no Bt (var. Dracma) sin tratamiento insecticida y maíz no Bt pildorado con imidacloprid. Del mismo modo, se compararon los efectos de estos tres tratamientos en la riqueza y diversidad de especies de carábidos y arañas terrestres. El 94% de los depredadores encontrados en el muestreo visual se compuso de: arañas, dos especies del género Orius, Stethorus punctillum y Chrysoperla carnea; el 95% de los depredadores capturados en trampas de gravedad fueron arañas, carábidos y estafilínidos. Todos ellos son depredadores generalistas, excepto S. punctillum, que es depredador especialista de ácaros fitófagos. En cuanto a la abundancia de depredadores, sólo los estafilínidos vieron disminuida significativamente su abundancia en el tratamiento de maíz Bt, aunque estas diferencias se concentraron en una fecha concreta del muestreo en los años 2000 y 2002. Los índices de riqueza y diversidad de las comunidades de arañas y carábidos terrestres no variaron significativamente entre tratamientos

Management of acute diverticulitis with pericolic free gas (ADIFAS). an international multicenter observational study

Background: There are no specific recommendations regarding the optimal management of this group of patients. The World Society of Emergency Surgery suggested a nonoperative strategy with antibiotic therapy, but this was a weak recommendation. This study aims to identify the optimal management of patients with acute diverticulitis (AD) presenting with pericolic free air with or without pericolic fluid. Methods: A multicenter, prospective, international study of patients diagnosed with AD and pericolic-free air with or without pericolic free fluid at a computed tomography (CT) scan between May 2020 and June 2021 was included. Patients were excluded if they had intra-abdominal distant free air, an abscess, generalized peritonitis, or less than a 1-year follow-up. The primary outcome was the rate of failure of nonoperative management within the index admission. Secondary outcomes included the rate of failure of nonoperative management within the first year and risk factors for failure. Results: A total of 810 patients were recruited across 69 European and South American centers; 744 patients (92%) were treated nonoperatively, and 66 (8%) underwent immediate surgery. Baseline characteristics were similar between groups. Hinchey II-IV on diagnostic imaging was the only independent risk factor for surgical intervention during index admission (odds ratios: 12.5, 95% CI: 2.4-64, P =0.003). Among patients treated nonoperatively, at index admission, 697 (94%) patients were discharged without any complications, 35 (4.7%) required emergency surgery, and 12 (1.6%) percutaneous drainage. Free pericolic fluid on CT scan was associated with a higher risk of failure of nonoperative management (odds ratios: 4.9, 95% CI: 1.2-19.9, P =0.023), with 88% of success compared to 96% without free fluid ( P <0.001). The rate of treatment failure with nonoperative management during the first year of follow-up was 16.5%. Conclusion: Patients with AD presenting with pericolic free gas can be successfully managed nonoperatively in the vast majority of cases. Patients with both free pericolic gas and free pericolic fluid on a CT scan are at a higher risk of failing nonoperative management and require closer observation

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Susceptibility to the Cry1F toxin of field populations of Sesamia nonagrioides (Lepidoptera: Noctuidae) in Mediterranean maize cultivation regions

9 páginas, 3 figuras, 3 tablas -- PAGS nros. 214-221Maize hybrids expressing the Cry1F toxin provide efficient control of lepidopteran pests. The Mediterranean corn borer, Sesamia nonagrioides (Lefèvre), is one of the most damaging pests of maize in the Mediterranean basin. In this work we firstly determined the efficacy of maize hybrids expressing the Cry1F toxin (event TC1507) to control neonates of S. nonagrioides. Leaf tissue feeding bioassays revealed that TC1507 maize is highly effective against this pest, and the percentage mortality obtained was comparable to that obtained with a Cry1Ab-expressing maize hybrid (Compa CB, event 176), which is known to be highly efficacious against S. nonagrioides. Secondly, interpopulation variation in the susceptibility to the Cry1F insecticidal protein was established for nine field-collected populations of S. nonagrioides (three Spanish, two French, two Italian, one Greek, and one Turkish). Estimates of the susceptibility of larvae to the Cry1F toxin showed low variability in lethal concentrations and growth inhibition concentrations among field populations. Moreover, no significant differences were found when they were grouped by geographical areas [Western Mediterranean (Spain and France) versus Eastern Mediterranean (Italy, Greece and Turkey)] or by history of exposure to Bt plants (Spanish vs. other populations). Therefore, the minor differences found in field populations can be attributed to natural variation in sensitivity to Cry1F. The importance of establishing baselines of susceptibility for resistance detection is discussed. Future changes in susceptibility of S. nonagrioides populations to Cry1F could be documented based on this baseline dataPeer reviewe

Post-market environmental monitoring of Bt maize in Spain: Non-target effects of varieties derived from the event MON810 on predatory fauna

9 p.-5 tab.[EN]The Spanish Government has established post-market environmental monitoring (PMEM) as mandatory for genetically modified (GM) crop varieties cultivated in Spain. In order to comply with this regulation, effects of Bt maize varieties derived from the event MON810 on the predatory fauna were monitored for two years in northeast and central Spain. The study was carried out with a randomized block design in maize fields of 3-4 ha on which the abundance of plant-dwelling predators and the activity-density of soil-dwelling predators in Bt vs. non-Bt near-isogenic varieties were compared. To this end, the plots were sampled by visual inspection of a certain number of plants and pitfall traps 6 or 7 times throughout two seasons. No significant differences in predator densities on plants were found between Bt and non-Bt varieties. In the pitfall traps, significant differences between the two types of maize were found only in Staphylinidae, in which trap catches in non-Bt maize were higher than in Bt maize in central Spain. Based on the statistical power of the assays, surrogate arthropods for PMEM purposes are proposed; Orius spp. and Araneae for visual sampling and Carabidae, Araneae, and Staphylinidae for pitfall trapping. The other predator groups recorded in the study, Nabis sp. and Coccinellidae in visual sampling and Dermaptera in pitfall trapping, gave very poor power results. To help to establish a standardized protocol for PMEM of genetically modified crops, the effect-detecting capacity with a power of 0.8 of each predator group is given.[ES]Con el objetivo de cumplir con la legislación española que establece la obligatoriedad de un plan de seguimiento ambiental para post-comercialización (PMEM) para los cultivos modificados genéticamente, se evaluó durante dos años el efecto de variedades de maíz Bt derivadas del evento MON810 en la fauna depredadora, en el nordeste y centro de España. El estudio se realizó mediante un diseño de bloques al azar, en campos de maíz de 3-4 ha, en los cuales se comparó la abundancia/actividad de depredadores en planta y en el suelo entre variedades de maíz Bt y no-Bt. Las parcelas se muestrearon de 6 a 7 veces durante cada uno de los dos años mediante inspección visual de un número determinado de plantas y por medio de trampas de gravedad. No se observaron en general diferencias significativas en la densidad de depredadores en planta y en el suelo entre las variedades Bt y no-Bt y sólo los Staphylinidae mostraron capturas significativamente mayores en parcelas no Bt en el centro de España. En base a la potencia estadística obtenida de los análisis se proponen una serie de artrópodos indicadores para los ensayos de PMEM: Orius spp. y Araneae en los muestreos visuales y Carabidae, Araneae y Staphylinidae en los muestreos con trampas de gravedad. El resto de grupos registrados en el estudio, Nabis sp. y Coccinellidae en los muestreos visuales y Dermaptera en las trampas de gravedad, mostraron una potencia considerablemente menor. Se hacen recomendaciones para el diseño de ensayos para PMEM.This study is part of the PMEM plan of GM varieties based on event MON810.Peer reviewe

Diversity and seasonal phenology of the above-ground arthropods in conventional and transgenic maize crops of Central Spain

10 páginas, 2 figuras, 3 tablas -- PAGS nros. 362-371One of the major concerns regarding the release of Bt maize is its potential negative impact on non-target organisms present in this crop. In this paper, we compare the temporal phenology and community structure of the aboveground arthropods in commercial Bt maize fields in Central Spain with those of conventional maize crops, with or without an insecticide (imidacloprid) seed treatment, over a period of three years. Spiders, harvestmen, centipedes, ground beetles, rove beetles, carrion beetles, click beetles, earwigs and damsel bugs were captured in pitfall traps every year in sufficient number to provide meaningful phenological data. One predator spider and three omnivorous species of ground beetles have been consistently present in the maize fields: Pardosa occidentalis, Poecilus cupreus, Pseudophonus rufipes and Pseudophonus griseus, respectively. Rove beetles were caught to a lesser extent, with three dominant species: Acrotona aterrima, Philonthus varians and Platystethus nitens. The variability in activity–density patterns of the aboveground fauna was mainly influenced by the year, but no detrimental effects could be attributed to Bt maize. The only exception being the changes detected in rove beetles, although these differences were transitory and varied from year to year. No changes in species richness and diversity indices for spiders and ground beetles resulted from treatments. However, imidacloprid-treated maize caused a reduction in species richness of rove beetles, even though the abundance of the main species was not reduced. Our results suggest that Bt maize could be compatible with natural enemies that are common in maize fields in SpainThis work was supported by grants from the Spanish Ministry of Environment and the European Commission (FP6-502981). Gema P. Farinós has a postdoctoral contract of the CSIC’s I3P programme, funded by the European Social FundPeer reviewe

Editorial: Identifying agri-food research priorities for Spain - 2017 results

Among other functions, the INIA is involved in national and international cooperation in the field of agri-food research. The process of identifying and classifying gaps in our knowledge forms an essential part of this effort. This article describes that process, the tools and the materials used to achieve the final objective, namely, the identification of research priorities in the Spanish agri-food sector in order to deal with the societal challenges posed by society and the stakeholders involved. These challenges, within the context of the bioeconomy, are the sustainability of primary and forestry production systems, the safety and quality of food and bioproducts as well as the competitiveness of farmers and companies in this sector. It is necessary to optimize resource management and means of production along with improved efficiency to guarantee sustainability throughout the value chain process. The main goal, under the current scenario of climate change, is to develop models which lead to a balance between food quality and production costs (competitiveness and economic sustainability), ecosystem conservation and mitigation of the environmental impacts (environmental sustainability) while maintaining the population in rural areas (social sustainability). These models will be based on new technology in both intensive and extensive production systems. They should support the improvement and valuation of traditional products together with the formulation and development of foods with new functionalities and quality while at the same time ensuring safety. As well as satisfying consumer demand, improved knowledge must lead to a more efficient use of our own resources and by-products within the framework of a circular economy, including the development of bioproducts, eco-innovation and eco-design

Identifying agri-food research priorities for Spain. 2017 results

Among other functions, the INIA is involved in national and international cooperation in the field of agri-food research. The process of identifying and classifying gaps in our knowledge forms an essential part of this effort. This article describes that process, the tools and the materials used to achieve the final objective, namely, the identification of research priorities in the Spanish agri-food sector in order to deal with the societal challenges posed by society and the stakeholders involved. These challenges, within the context of the bioeconomy, are the sustainability of primary and forestry production systems, the safety and quality of food and bioproducts as well as the competitiveness of farmers and companies in this sector. It is necessary to optimize resource management and means of production along with improved efficiency to guarantee sustainability throughout the value chain process. The main goal, under the current scenario of climate change, is to develop models which lead to a balance between food quality and production costs (competitiveness and economic sustainability), ecosystem conservation and mitigation of the environmental impacts (environmental sustainability) while maintaining the population in rural areas (social sustainability). These models will be based on new technology in both intensive and extensive production systems. They should support the improvement and valuation of traditional products together with the formulation and development of foods with new functionalities and quality while at the same time ensuring safety. As well as satisfying consumer demand, improved knowledge must lead to a more efficient use of our own resources and by-products within the framework of a circular economy, including the development of bioproducts, eco-innovation and eco-design

Comparative assessment of the field-susceptibility of Sesamia nonagrioides to the Cry1Ab toxin in areas with different adoption rates of Bt maize and in Bt-free areas

5 páginas, 1 figura, 2 tablas -- PAGS nros. 902-906A three year (2003–2005) field study compared the susceptibility to the Cry1Ab toxin, expressed in Bt maize, of Mediterranean corn borer (MCB) Sesamia nonagrioides populations collected from areas with different adoption rates of Bt maize in Spain with Bt-free areas in Greece. Spain is the only European country where the cultivar Compa CB derived from the event Bt176 was commercially grown, from 1998 to 2005. The large decrease of the titer of the toxin in this cultivar at later growth stages represented the worst-case scenario for resistance development of MCB, since larvae of the second and third generations were exposed to sublethal concentrations of Cry1Ab toxin. Our data revealed that the variation in susceptibility to Cry1Ab for the MCB Spanish field populations analyzed in the three years was very low, with LC50 values fluctuating between 12 and 30 ng Cry1Ab/cm2, regardless of the region of origin, the type of maize (Bt or non-Bt) and the year. Furthermore, no significant differences were found when comparisons were made with a laboratory population (LC50 values: 18–26 ng Cry1Ab/cm2) or with field populations from Greece (Bt-free areas), which displayed LC50 values ranging between 22 and 27 ng Cry1Ab/cm2. Standardizing bioassay protocols proved to be essential for obtaining comparable results. These findings suggest that resistant MCB populations did not evolve in those Spanish maize areas where Compa CB was largely cultivated for eight years, contradicting the expected rapid development of resistance under these unfavourable conditions. Additionally, our results can be used as baseline indices in post-market resistance monitoring programs if Bt maize is introduced in Greece. Further studies should continue, since the insights gained from a resistance monitoring program may help to enhance the durability of Bt maizeThis work was funded by The Spanish Ministry of Environment and grants from the EU, Proposal No QLRT-2001-01969 (Protecting the Benefits of Bt toxins from Insect Resistance Development by Monitoring and Management). Gema P. Farinós had a postdoctoral contract of the CSIC’s I3P programme, funded by the European Social Fund.Peer reviewe