Re-Evaluation of Yam Mosaic Virus (YMV) Detection Methods

Accurate and timely detection is vital for mitigation of tuber yield losses resulting from yam mosaic virus (YMV) infection on yam, a major food security crop in West Africa. The observation, from our previous studies, that the triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA), the most commonly used detection method for YMV, detected the virus in significantly less leaf samples than immunocapture reverse transcription polymerase chain reaction (IC-RT-PCR) necessitated a re-evaluation of YMV detection methods. In the present study, eighteen previously tested YMV positive leaf samples from Benin and Ghana were re-tested using TAS-ELISA, Protein A-sandwich (PAS) ELISA and IC-RT-PCR. Three sap dilutions, 1/10, 1/50 and 1/100, were tested for each sample. Both at 1/10 and 1/50 dilutions, PAS-ELISA and IC-RT-PCR detected YMV in 11 (61.1%) and 12 (66.7%) of the leaves respectively. Virus detection by PAS-ELISA reduced to 50% at 1/100 sap dilution and increased to 77.8% in IC-RT-PCR. YMV detection by TAS-ELISA varied between 38.9% and 16.7% at 1/10 and 1/100 dilutions respectively. These results indicate a deficiency in the use of TAS-ELISA as a sole YMV certification method since the detecting monoclonal antibody used in this assay may be strain specific. The use of PAS-ELISA at a 1/10 sap dilution is suggested for YMV detection where the facilities for molecular detection are unavailabl

Effect of water yam (Dioscorea alata) flour fortified with distillers spent grain on nutritional, chemical, and functional properties

It was envisaged that the inclusion of treated distiller ’ s spent grain ( DSG ) to yam fl our might increase its nutritional value, with the aim of reducing nutritional diseases in communities consuming yam as a staple. Hence, yam fl our was fortifi ed with DSG at 5–35%. The effects of this fortifi cation on the nutritional, chemical, and functional properties of yam fl our were investigated. The result showed a signifi cant increase ( P 0.001) in fat, ash, protein, total amino acids, total dietary fi ber, and insoluble dietary fi ber contents of the blends as DSG increased except for starch and soluble dietary fi ber contents, which decreased. The functional properties showed a signifi cant ( P 0.001) reduction with DSG inclusion. The inclusion of DSG increased both the tryptophan and methionine contents of the blends. Therefore, the DSG fortifi ed yam fl our could contribute to quality protein intake in populations consuming yam as a staple, due to its indispensible amino acid content

Combined Inflammatory and Metabolic Defects Reflected by Reduced Serum Protein Levels in Patients with Buruli Ulcer Disease

Buruli ulcer is a skin disease caused by Mycobacterium ulcerans that is spreading in tropical countries, with major public health and economic implications in West Africa. Multi-analyte profiling of serum proteins in patients and endemic controls revealed that Buruli ulcer disease down-regulates the circulating levels of a large array of inflammatory mediators, without impacting on the leukocyte composition of peripheral blood. Notably, several proteins contributing to acute phase reaction, lipid metabolism, coagulation and tissue remodelling were also impacted. Their down-regulation was selective and persisted after the elimination of bacteria with antibiotic therapy. It involved proteins with various functions and origins, suggesting that M. ulcerans infection causes global and chronic defects in the host’s protein metabolism. Accordingly, patients had reduced levels of total serum proteins and blood urea, in the absence of signs of malnutrition, or functional failure of liver or kidney. Interestingly, slow healers had deeper metabolic and coagulation defects at the start of antibiotic therapy. In addition to providing novel insight into Buruli ulcer pathogenesis, our study therefore identifies a unique proteomic signature for this disease

Chromogenic detection of yam mosaic virus by closed-tube reverse transcription loop-mediated isothermal amplification (CT-RT-LAMP)

A closed-tube reverse transcription loop-mediated isothermal amplification (CT-RT-LAMP) assay was developed for the detection of yam mosaic virus (YMV, genus Potyvirus) infecting yam (Dioscorea spp.). The assay uses a set of six oligonucleotide primers targeting the YMV coat protein region, and the amplification products in YMV-positive samples are visualized by chromogenic detection with SYBR Green I dye. The CT-RT-LAMP assay detected YMV in leaf and tuber tissues of infected plants. The assay is 100 times more sensitive in detecting YMV than standard RT-PCR, while maintaining the same specificity

Priority interventions for transformational change in the Sahel

The Sahel region holds both challenges and opportunities for smallholder agriculture and agro pastoralism. Market opportunities for food producers in the region have improved due to population growth, urbanization, income growth, dietary diversification and higher output prices. However, alongside land degradation and climate change, conflicts and epidemics, an increased dependence on dynamic food (and feed) value chains and on volatile markets indicates the need to address structural constraints such as limited access to high-potential agricultural innovations, ineffective policies, an underdeveloped business environment, poor infrastructure and processing facilities and a generally poor market infrastructure. To support the agricultural transformation required to meet these challenges, evidence needs to be provided to countries in the Sahel to enable them make informed decisions on policy reforms and supporting actions where and when needed. Several scaling approaches and technological solutions have been demonstrated to be effective and this document outlines proposed priority actions to achieve higher adoption of climate smart agriculture through Public-Private-Partnerships. A particular focus will be on the role of women and youth, both through improved household nutrition (and other attendant health and development benefits) and through improved job creation and wealth generation in various components of selected value chains. Meanwhile, the importance of improved agro-industrialization and trade for income generation and poverty reduction underscores the critical role of enhanced interaction with a vibrant private sector. This document presents some of the main routes by which R4D can contribute to agricultural transformation in the Sahel towards inclusive and sustainable economic growth, social development and resilience, including climate smart agricultural technologies appropriate to smallholder farming families. This will be achieved through a six-pronged strategy: (i) Increasing the efficiency of tree, crop and livestock value chains, (ii) Empowerment and increased employment opportunities for women and youth in agriculture, (iii) Co-creation of context-specific, climate smart innovations to enhance climate resilience (iv) Value addition and improved nutrition, (v) Improved soil and water conservation and its utilization for production, Improved policy and institutional enabling environments