THE ROSE POWDERY MILDEW (Podosphaera pannosa)

Articulo de revisión, sobre el estado actual de Podosphaera pannosaEn México la rosa (Rosa sp.) es una especie ornamental con importancia económica y una de las más demandadas; entre las enfermedades que la afectan destaca la cenicilla. Esta enfermedad es causada por el biótrofo Podosphaera pannosa y repercute en la productividad, calidad, comercialización y costos de producción. Entre los fungicidas empleados para el control de la enfermedad destacan los inhibidores de la desmetilación y de la biosíntesis del ergosterol, y las estrobilurinas que inhiben la respiración mitocondrial. Algunos de estos fungicidas pierden su eficacia debido a la resistencia que va adquiriendo el patógeno. El desarrollo del patógeno está condicionado por diferentes aspectos bioecológicos y la variabilidad genética; a pesar de que se cuenta con un grupo amplio de medidas, genéticas y biológicas, su control es insuficiente. Actualmente, una alternativa es utilizar inductores de resistencia, como fosfito de potasio, silicio y acibenzolar-s-metil, contra patógenos como Peronospora sparsa y P. pannosa en el cultivo de rosa. En este ensayo se analizó la información actual de la cenicilla del rosal y proporciona perspectivas para estudios futuros de la enfermedad.Universidad Autónoma del Estado de Méxic

Potato virus X (PVX) elimination as short and long term effects of hydrogen peroxide and salicylic acid is differentially mediated by oxidative stress in synergism with thermotherapy

Articulo científico indezadoAbstract Short and long term effects of hydrogen peroxide (H2O2) and salicylic acid (SA) were examined in: thermotolerance, virus X (PVX)-free microplants obtained by in vitro thermotherapy, catalase activity (CAT) and H2O2 concentration. Short term effects (STE) were tested as follows: (a) nodal explants were cultivated 30 d on MS medium containing SA 10−5 or 10−6 M; and (b) nodal explants were waterlogged for 1 h in 1 or 5 mMH2O2 solution and subsequently cultured in MS for 30 d. Long term effects were tested as follows (LTE): the experimental regime was identical to STE but SA and H2O2 treated plants were subcultured for an additional 30 d period onMS. All treatments were followed by thermotherapy (32–42 C) for 35 d. Results showed SA and H2O2 induced thermotolerance during thermotherapy. The percentage of PVX-free plants obtained in H2O2 was significantly higher than in SA in STE and LTE by 3-and 4 fold respectively. CAT activity was differentially mediated by SA and H2O2.This research was supported by a grant from Recursos Fiscales, INIFAP

Efecto del ácido ascórbico sobre crecimiento, pigmentos fotosintéticos y actividad peroxidasa de plantas de rosal

El ácido ascórbico (AA) participa en muchos procesos fisiológicos tales como: fotosíntesis, cofactor enzimático, homeostasis del sistema redox, precursor en las rutas de síntesis de moléculas del metabolismo primario y secundario, entre otras funciones. En el presente trabajo, se evaluó el efecto del AA en plantas de rosal variedad Fetera® en condiciones de invernadero. El objetivo fue evaluar el efecto de la molécula antioxidante AA como un compuesto alternativo involucrado en las respuestas de crecimiento, contenido de pigmentos fotosintéticos y actividad enzimática de la peroxidasa (POX), en el cultivo de rosal variedad Fetera®. Las plantas se asperjaron dos veces por semana con 0, 600 y 1200 mg L-1 de AA durante cinco meses. El tratamiento de AA incrementó la longitud y el diámetro del tallo, así como el número de brotes laterales en las plantas de rosal. Las plantas asperjadas con AA mostraron incremento de los pigmentos fotosintéticos y la actividad enzimática de la POX. Los avances de este trabajo indican que el AA puede ser un compuesto potencialmente útil para incrementar el crecimiento del cultivo de rosal

Incidence of Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) and defense mechanisms in Gerbera hybrida

The existence of natural variation at different levels of whitefly infestation (Trialeurodes vaporariorum) in gerbera genotypes (Gerbera hybrida) allows the existence of different levels of resistance or susceptibility to the insect. In this investigation the natural variation of gerbera was evaluated at the incidence of T. vaporariorum. In a randomized complete block design, ten gerbera genotypes were analyzed in different phenological stages without incidence (SI) and with incidence (CI) of whitefly. Nymphs were counted, in a cm2 at the center of the underside of the leaves and total adults per leaf. The relative content of chlorophyll (USPAD), the content of phenolic compounds (Cf), the enzymatic activity of peroxidases (AePOX) and the antioxidant capacity DPPH (Caox) were measured. Gerbera genotypes showed significant differences in the incidence of whiteflies (p≤ 0.01), as well as in Cf, AePOX and Caox, both in SI and CI (p≤ 0.01), which suggests differences in insect preference a its host and the ability of genotypes to respond to whiteflies. In CI with respect to SI, they increased the content of Cf (1.4 times), AePOX (4 times) and Caox (12 times). USPAD decreased in the genotype with the highest incidence of the insect (-4%). The significant correlations between the number of insects (nymphs) with Cf (-0.71**) and AePOX (-0.65**) and Caox with Cf (-0.73**) and AePOX (-0.76**), showed that the feeding of the insect interferes with the metabolism of its hosts and triggers integral responses in the defense mechanism of plants, with differences in resistance that can be used in genetic improvement

Nutrición para la producción de minitubérculos de papa de variedades mexicanas bajo condiciones de hidroponía

Antecedentes. La producción de semilla de papa en Latinoamérica es realizada por métodos de multiplicación rápida, utilizando secciones enraizadas de tallo o plantas in vitro, lo que permite el desarrollo de esquemas de producción de semilla de alta calidad fitosanitaria (Donelly et al., 2003), y ha incrementado la tasa de multiplicación de 1:5 hasta 1:20 papas (Ezeta, 2001). Estudios hechos en México con densidades de población en hidroponía en la variedad Gigant, demostraron que las altas densidades disminuyen la acumulación de materia seca, el número de tubérculos mayores a 10 mm, así como la tasa absoluta de crecimiento y la tasa de asimilación neta (Flores-López et al., 2009). Aunque, la hidroponía se usa en la producción de minitubérculos de papa (Lommen, 2007), se requiere de la generación de tecnología apropiada para cada cultivar, dada la diversidad genética que existe en Latinoaméric

Potassium fosfites in Peronospora sparsa Berkeley management and flower quality of rose cv. Samouraï®

Peronospora sparsa Berkeley limita hasta 100% la producción de rosa como flor de corte. Una alternativa sustentable en el control de oomicetos en diversos cultivos es el uso de fosfitos de potasio. Los objetivos de la presente investigación fueron evaluar la efectividad biológica de formulaciones comerciales de fosfito de potasio para el manejo de P. sparsa, y estimar el efecto de las aplicaciones de fosfitos en la calidad del tallo y el botón floral de rosa cv. Samouraï®. Se utilizó un diseño de bloques completos al azar con cinco tratamientos y un testigo absoluto con seis repeticiones, por dos años consecutivos. Se evaluó incidencia, severidad de la enfermedad, efectividad biológica, así como la calidad floral mediante la longitud y el diámetro de tallos y botones florales. Los fosfitos de potasio evaluados redujeron la incidencia hasta 81.7% y la severidad pasó de 71.7 a 97.0%, lo que llevó a una efectividad biológica de 96.9% con FosfiMax 40-20®. El tratamiento con Defense Ax® incrementó la longitud y el diámetro del botón con respecto a los otros tratamientos

Bactericidal effect of silver nanoparticles against propagation of Clavibacter michiganensis infection in Lycopersicon esculentum Mill

This study explored the use of silver nanoparticle as a bactericidal against the propagation of Clavibacter michiganensis onto tomatoes (Lycopersicon esculentum Mill). In Mexico, tomato production covers about 73% of the total vegetable production but it is affected by outbreak of bacteria canker caused by Clavibacter michiganensis subspecies michiganensis (Cmm). Silver ions possess inhibitor properties, bactericides and high specter antimicrobials. In this study, 6 groups of culture were prepared using 6 different petri dishes where silver nanoparticles of varying concentrations (120, 84, 48, 24, 12 and 0 μg) were added. Furthermore, each group was observed for 20 min, 1, 2, 12 and 24 h. The optimum concentration is 84 μg, which shows an average of 2 Cmm colonies after 20 min. Further increase to 120 μg shows no significant change. However, the average colonies was observed for 48 μg after 1, 2, 12, and 24 h. The obtained results indicate that silver nanoparticles are a promising inhibitor, bactericide and high a specter antimicrobial for treatment or prevention of Cmm

Desafíos actuales de la educación superior

El presente libro corresponde al trabajo investigativo realizado por sus autores frente a los desafíos que enfrenta y enfrentará la educación en tiempos actuales (provisional)

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication