SATrends Issue 71 October 2006
  • An aflatoxin check for humans
  • Niamey Declaration: From Desert to Oasis
  • BecA Beckons
  • Pooling to ponder the power of water

  • 1. An aflatoxin check for humans
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    A simple enzyme-linked immunosorbent assay (ELISA) test has been developed to determine the human exposure to aflatoxin B1 - the carcinogenic compound responsible for human liver cancer and other health disorders.

    Aflatoxin B1 (AfB1) is the naturally produced food-borne metabolite of Aspergillus flavus and related fungi found in human food and animal feed. Severe intoxication due to consumption of highly contaminated food results in acute liver damage and even death. Frequent exposure to sub-lethal doses leads to nutritional and immunological consequences and greatly increases the risk of liver cancer. Research during the past two decades has established a synergistic interaction between Hepatitis B virus infection and AfB1 in causing liver cancer. Various studies suggest that the chronic type of aflatoxin poisoning is common in many parts of developing countries in Asia and Africa, and it usually goes unnoticed.

    ELISA

    A simple ELISA test was developed to monitor human exposure to aflatoxins for identifying individuals at high risk. This test is based on the estimation of AfB1-lysine, a metabolite of AB1, whose concentration in the blood albumin fraction has been shown to correlate with dietary aflatoxin intake over the previous 2-3 months and the level of DNA damage in the liver.

    The test involves isolation of the albumin fraction from blood, followed by digestion of albumin and estimation of AfB1-lysine content by ELISA using AfB1-lysine polyclonal antibodies. In the ELISA test, antibodies are first bound to the AfB1-lysine present in the extracted albumin. Then, the antibody-AfB1-lysine complex is detected using an enzyme-labeled reporter antibody. Finally, the enzyme-labeled reporter antibody is detected using a colorimetric reaction that provides an estimate of the original AfB1-lysine concentration. The current test can detect levels of AfB1-lysine in blood as low as 5 picogram per milligram (pg/mg) albumin. The estimated cost for each analysis is around US$3.00. The test is simple to perform, inexpensive and is effective for routine monitoring of human as well as animal samples for aflatoxin exposure.

    This latest test for monitoring aflatoxin exposure in humans complements the low-cost diagnostic test (about US$1.00 per sample) developed earlier by ICRISAT for the detection of aflatoxins in agriculture commodities. Both the tests now allow ICRISAT and its partners to conduct field studies to identify aflatoxin-exposed populations, determine the source of contaminated food and stimulate appropriate management approaches to limit dietary-aflatoxin exposure, thereby enhancing the safety of food and human health.

    For further information contact f.waliyar@cgiar.org or p.lavakumar@cgiar.org

    2. Niamey Declaration: From Desert to Oasis
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    The world sees the drylands of sub-Saharan Africa (SSA) as degraded places full of suffering, with no hope of improvement. But these drylands are home to some of the most productive agriculture in the world. To explore this vision, ICRISAT, the Desert Margins Program (DMP), the UNCCD and Oasis organized a Symposium/Workshop titled From Desert to Oasis: the role of science and research in combating desertification in semi-arid sub-Saharan Africa, from 23 to 25 September at Niamey, Niger. The event gave birth to a new resolution called the Niamey Declaration, which was adopted by all the participants.

    In this Year of Deserts and Desertification, this event emphasized the new 'Oasis' Systemwide Program to combat desertification, which was jointly convened by ICRISAT and ICARDA and has up to now enlisted 11 CGIAR Centers as partners. Some of the eminent speakers at the symposium were the UNCCD Executive Secretary Ambassador Hama Arba Diallo, Dr Chris Reij of Wageningen University and Dr Musa Mbenga of CILSS.

    Desert

    Appreciating the efforts of the organizers and all the other supporters across Africa, the Niamey Declaration expressed gratitude to the Niger Government and to its Prime Minister for welcoming and supporting this international event on behalf of the African continent.

    The Declaration considered dryland degradation to be an insidious threat to all of Africa, which culminates in intense human suffering. It took note that attention has to be drawn not just to catastrophes, such as famines, but also to the inspiring cases of success resulting from the quiet dedication of millions to build better lives. Attention must be paid to the opportunity to learn from, and capitalize on, these successes so as to spread their benefits more widely.

    Further, development-oriented scientific research must be mobilized to capture and build on these lessons. In order to be successful, research and knowledge-sharing must address the priority needs of the poor and engage cross-disciplinary partnerships. Highlighting the comparative advantages of the drylands with its powerful assets for overcoming poverty, it advocates on and off-farm diversification.

    The Declaration emphasizes research on dryland policy options and consequences. It underlines the need for research to document the costs of dryland degradation, and to quantify the benefits that could accrue from sustainable rehabilitation.

    The resolution encourages better communication and endorses the 'Oasis' international research-for-development program.

    The full text of the declaration can be found at http://www.oasisglobal.net/

    For more information contact B.Shapiro@cgiar.org

    3. BecA Beckons
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    The concept of a regional biosciences network for eastern Africa was initiated in 2002. This was later developed into Biosciences eastern and central Africa (BecA) through support from the Canadian International Development Agency's Canada Fund for Africa. The BecA Hub is based at the International Livestock Research Institute (ILRI) Campus, Nairobi, and comprises a shared research platform. Construction and procurement of equipment is scheduled to start in January 2007 and the plant biotechnology suite will be ready for use from mid-2008.

    In the interim, ICRISAT's biotechnologists have been using the good tissue culture facilities of the Kenya Agricultural Research Institute (KARI). The benefit is mutual, as these activities are also used as capacity building opportunities to train KARI personnel. KARI is a member of the BecA network, and on establishing that the KARI facility lacked some crucial equipment, ILRI agreed to lend the required equipment to KARI on long-term loan. This arrangement is a novel solution that is mutually beneficial to the CG centres and the NARS partners until the ILRI/BecA shared research platform is completely established.

    BecA laboratory
    Initial phase of the ILRI/BecA shared research platform.

    The goals of BecA include:

    • Creating and strengthening human capital in biosciences and related disciplines.
    • Promoting scientific excellence by bringing together a critical mass of scientists drawn from national, regional and international institutions in state-of-the-art facilities where they can undertake cutting-edge research to help solve constraints faced by the poor in Africa.
    • Increasing access to affordable, world-class research facilities within Africa.
    • Producing, managing and disseminating bioscience knowledge of relevance to Africa's development.
    • Facilitating access to advice and training on biosafety and intellectual property management issues.
    • Serving as a platform for forging partnerships with other biosciences initiatives in other regions of Africa and worldwide.

    Facilities will include state-of-the-art research laboratories for biosciences, including genomics, proteomics, gene technology, immunology and new containment facilities for safe genetic manipulation of plants and micro-organisms, and safe handling of pathogens used in research programs.

    ICRISAT is already using the genotyping facility that exists at the ILRI/BecA shared research platform to facilitate its biotechnology activities in the ESA region, specifically for marker-assisted breeding. The BecA platform is open for advancing applied science in Africa through partnerships with all qualified institutions and individuals. ICRISAT is hosted in the platform and provides technical backstopping and training to NARS partners.

    The immediate clients are the African scientific and agricultural communities and national and international agencies involved in agricultural research for development. The ultimate beneficiaries will be poor agricultural producers and consumers across Africa.

    For more information on ICRISAT activities contact S.Devilliers@cgiar.org

    4. Pooling to ponder the power of water
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    Management of water resources is a key task in agricultural practice around the world. But it is more so in Eastern and Southern Africa (ESA), because of the recurrent droughts. The full potential of water has to be harnessed to mitigate the effects of droughts.

    watershed

    A second workshop on Agricultural water management in Eastern and Southern Africa organized in Maputo, Mozambique, from 18 to 22 September made an attempt to address this issue. Held under the auspices of IMAWESA - the project on Improving management of agricultural water in Eastern and Southern Africa, which is supported by an IFAD grant to ASARECA and ICRISAT, and implemented by SWMnet, the workshop brought together over 125 participants for technical and policy discussions.

    The Ministers and Permanent Secretaries from Kenya, Mozambique, Rwanda and Lesotho participated in the workshop. ICRISAT was represented by the DDG-R Dyno Keatinge, together with Said Silim, Steve Twomlow and other scientists. There was also a strong delegation from IWMI led by the Africa Regional Director, Dr Akissa Bahri. ICRISAT and IWMI also discussed the south-south partnership between ICAR and ASARECA.

    Issues discussed

    1. Performance of past investment programs and projects in irrigation and other agricultural water interventions in ESA
    2. Alternative interventions for improving productivity and benefits from agricultural water, especially with respect to: investments, improving returns to agricultural water and integrated solutions, which remove the "artificial" distinction between rainfed and irrigated systems
    3. Options of policy and institutional frameworks that work, as well as process for participatory policy dialogue.

    Areas of intervention:

    • Fully exploit the potential of rainfed agriculture including pastoralism, by maximizing the integration of water management with other productivity enhancing interventions such as soil fertility and improved seeds
    • Improve financing of investments into smallholder water management operations with efforts put on market linkages and local servings
    • Improve local level governance of water schemes to ensure accessibility and productive use by the smallholders
    • Improve the security of tenure and access with reference to land and water
    • Harmonize policies and institutional frameworks affecting AWM because most fall in different sectors
    • Improve policy dialogue and formulation specifically to ensure participation of the poor and marginalized.

    Both the technical workshop and policy dialogue round tables were designed to re-examine and re-think the policy options and intervention strategies, and the outcome was very promising.

    For more information contact N.Hatibu@cgiar.org