Isolement et caractérisation morphologique de moisissures productrices de substances antibactériennes à partir d’aliments locaux au Burkina Faso

En vue du risque augmenté jour après jour des bactéries résistantes aux antibiotiques, nous nous sommes intéressés dans cette étude à l’isolement et à la caractérisation des isolats de moisissures productrices d’antibiotique à partir d’aliments locaux du Burkina Faso. Cinquante (50) isolats fongiques isolés ont servis au test d’antibiose qui a révélé vingt (20) isolats producteurs de substances antimicrobiennes. Ce test a concerné les cellules des isolats ainsi que des extraits aqueux et organiques issues de ceux-ci. Trois (03) isolats ont présenté des diamètres d’inhibitions moyens de 20 mm sur les germes tests. Leur caractérisation a porté sur les critères morphologiques et culturaux. L’isolat S1 présente en 5 jours d’incubation sur la gélose de Pomme de Terre Dextrose (PDA) une colonie plate, de couleur blanche au recto, avec un revers jaune, l’isolat S2 une colonie vert-olive, de texture veloutée, plus dense au centre et l’isolat S3 une petite colonie de couleur verte et ronde. En microscopie optique les isolats S1 et S2 ont présenté des conidies rondes, réfringentes et nombreuses, les conidiophores sont hyalins, longs et non cloisonnés. L’isolat S3 a présenté des conidies rares, des pénicilles constitués de phialides branchés directement à l’extrémité des conidiophores cloisonnés. L’analyse de ces caractéristiques indique que S1, S2 et S3 appartiennent respectivement aux genres Aspergillus et Penicillium.© 2016 International Formulae Group. All rights reserved.Mots clés: Substances antimicrobiennes, Aspergillus, Penicillium, Burkina FasoEnglish Title: Isolation and morphological characterization of fungi producing antibacterial substances from local food in Burkina FasoEnglish AbstractBacterial resistance to the actual antibiotic is mostly in dangerous progress, why we have interest in isolation and characterization of fungi strains producing antibiotics using local food in Burkina Faso. Fifty (50) isolated strains were used in the antibiosis trial which revealed twenty (20) strains producing antimicrobial substances. This trial concerned the strains cell as well as its aqueous and organic extracts. Three (03) strains had average inhibition diameters of 20 mm on the testing germs. Their characterization focused on the  morphological and culture criteria. After five days of incubation in Potato Dextrose Agar (PDA), the strain S1 shows a flat colony, white on the front, with a yellow reverse. The strain S2 shows an olive-green colony, velvety texture, more dense in the center. As for the strain S3, it shows a round green colored colony. In optical microscopy, strains S1 and S2 showed numerous round and refractive conidia, conidiophores are hyaline, long and not partitioned. S3 strain showed uncommon conidia, penicillus made of phialides which are directly linked to the end of partitioned conidiophores. Analysis of these characteristics indicates that S1, S2 and S3 belong respectively to the Aspergillus and Penicillium genera.© 2016 International Formulae Group. All rights reservedKeywords: Antimicrobial substances, Aspergillus, Penicillium, Burkina Fas

Structural, physiognomic and above-ground biomass variation in savanna-forest transition zones on three continents - How different are co-occurring savanna and forest formations?

Through interpretations of remote-sensing data and/or theoretical propositions, the idea that forest and savanna represent "alternative stable states" is gaining increasing acceptance. Filling an observational gap, we present detailed stratified floristic and structural analyses for forest and savanna stands located mostly within zones of transition (where both vegetation types occur in close proximity) in Africa, South America and Australia. Woody plant leaf area index variation was related to tree canopy cover in a similar way for both savanna and forest with substantial overlap between the two vegetation types. As total woody plant canopy cover increased, so did the relative contribution of middle and lower strata of woody vegetation. Herbaceous layer cover declined as woody cover increased. This pattern of understorey grasses and herbs progressively replaced by shrubs as the canopy closes over was found for both savanna and forests and on all continents. Thus, once subordinate woody canopy layers are taken into account, a less marked transition in woody plant cover across the savanna-forest-species discontinuum is observed compared to that inferred when trees of a basal diameter > 0.1 m are considered in isolation. This is especially the case for shrub-dominated savannas and in taller savannas approaching canopy closure. An increased contribution of forest species to the total subordinate cover is also observed as savanna stand canopy closure occurs. Despite similarities in canopy-cover characteristics, woody vegetation in Africa and Australia attained greater heights and stored a greater amount of above-ground biomass than in South America. Up to three times as much above-ground biomass is stored in forests compared to savannas under equivalent climatic conditions. Savanna-forest transition zones were also found to typically occur at higher precipitation regimes for South America than for Africa. Nevertheless, consistent across all three continents coexistence was found to be confined to a well-defined edaphic-climate envelope with soil and climate the key determinants of the relative location of forest and savanna stands. Moreover, when considered in conjunction with the appropriate water availability metrics, it emerges that soil exchangeable cations exert considerable control on woody canopy-cover extent as measured in our pan-continental (forest + savanna) data set. Taken together these observations do not lend support to the notion of alternate stable states mediated through fire feedbacks as the prime force shaping the distribution of the two dominant vegetation types of the tropical lands

Fertilisation des sols avec la litiere foliaire en zone Subsahelienne du Burkina Faso: Diversite des especes, effets sur les rendements du sorgho

Organic matter sources management for soil fertility improvement has been the subject of many researches. Agroforestry is one of the topics addressed by these researches. In Burkina Faso\u2019s Northern Center, leaf litter of woody species is collected, piled, crumbled before spreading in fields. This practice is not well known in the rest of the country. The present study aims to provide information on the diversity of spontaneous plant species concerned, farmers\u2019 motivations of litter crumbling and to evaluate, empirically the effects of litter spreading on sorghum yields. A participatory study, using qualitative surveys and biometric field measurements, was conducted in five villages in the Northern Center of Burkina Faso. Because of their availability, accessibility, and agronomic performance, plants such as Vitellaria paradoxa , Anogeissus leiocarpa , Combretum micranthum , Lannea microcarpa and Diospyros mespiliformis were the species whose leaf litter was valued most. Measurements achieved in situ indicate that sorghum yields from fields that received Vitellaria leaf litter for the first time were lower than those in the control plots. On the other hand, fields that received this litter for three consecutive years were more productive. A scientific study on leaf litter chemical characteristics and their influence on soil fertility parameters should be considered in order to validate local knowledge and to improve knowledge about these practices.La gestion des sources de mati\ue8res organiques, pour am\ue9liorer la fertilit\ue9 des sols, a fait l\u2019objet de nombreuses recherches. L\u2019agroforesterie est une des th\ue9matiques abord\ue9es par ces recherches. Dans le Centre-Nord du Burkina Faso, la liti\ue8re foliaire des esp\ue8ces ligneuses est ramass\ue9e, mise en tas, \ue9miett\ue9e avant d\u2019\ueatre \ue9pandue dans les champs. Cette pratique est peu connue dans le reste du pays. La pr\ue9sente \ue9tude visait \ue0 fournir des informations sur la diversit\ue9 des esp\ue8ces v\ue9g\ue9tales spontan\ue9es concern\ue9es, les motivations paysannes de l\u2019\ue9miettement de la liti\ue8re et \ue0 \ue9valuer, empiriquement et par des mesures, les effets de l\u2019\ue9pandage de ces liti\ue8res sur les rendements du sorgho. Une \ue9tude participative, \ue0 l\u2019aide d\u2019enqu\ueates qualitatives et des mesures biom\ue9triques dans des champs, a \ue9t\ue9 men\ue9e dans cinq villages du Centre Nord du Burkina Faso. A cause de leur disponibilit\ue9, leur accessibilit\ue9, leur performance agronomique, les plantes telles que Vitellaria paradoxa , Anogeissus leiocarpa , Combretum micranthum , Lannea microcarpa , Diospyros mespiliformis ont \ue9t\ue9 cit\ue9es comme \ue9tant les esp\ue8ces dont la liti\ue8re des feuilles est valoris\ue9e. Les mesures r\ue9alis\ue9es in situ montrent que, les rendements du sorgho dans les champs ayant re\ue7u de la liti\ue8re foliaire de Vitellaria pour la premi\ue8re fois, ont \ue9t\ue9 inf\ue9rieurs \ue0 ceux des parcelles t\ue9moin. Par contre, les champs ayant re\ue7u cette liti\ue8re pendant trois ann\ue9es cons\ue9cutives ont \ue9t\ue9 plus productifs. Dans l\u2019optique de valider les savoirs locaux et d\u2019approfondir les connaissances sur l\u2019effet des liti\ue8res foliaires sur la fertilit\ue9 du sol, une \ue9tude scientifique sur leur caract\ue9ristique chimique et sur leur influence sur les param\ue8tres de fertilit\ue9 du sol, est \ue0 envisager

Les risques sanitaires lies a l\u2019utilisation des pesticides dans les bas-fonds rizicoles de la commune de dano, Province du Ioba Burkina Faso

Pesticides are an essential component of agricultural production techniques for pests and weeds control. In Burkina Faso, failure to observe good practices for pesticides use exposes farmers to health risks. The study presents health risks related to pesticide management in rice fields in Dano through a survey of 158 rice farmers working in inland valleys. Socio-demographic characteristics of farmers, the types of pesticides used and their effects on health were documented. Rice farming in Dano is mainly done by an ageing population with an average of over 50 years (60%). In addition, farmers\u2019 education level is low, with an illiteracy rate of 61 and only 32% of farmers attaining primary school education. Risky behaviours of pesticides use are common, especially inadequate of farmer protection, poor practices of storage and re-use of pesticide products. Twelve types of pesticides were identified, of which 40% are not officially registered. The main active components in herbicides are Glyphosate, Paraquat, Bensulfuron methyl and Bispyribac-sodium. Health risks of pesticide use reported by farmers included various poisoning symptoms. To mitigate pesticide poisoning prevalence associated with poor farming practices, awareness campaigns should be conducted to inform farmers to use pesticides safely.Les produits pesticides constituent de nos jours une composante essentielle des techniques de production agricole pour le contr\uf4le des ravageurs et des mauvaises herbes. Au Burkina Faso, le non respect des bonnes pratiques d\u2019utilisation des pesticides pose un v\ue9ritable probl\ue8me de sant\ue9 des populations. L\u2019\ue9tude pr\ue9sente les risques sanitaires de gestion des pesticides agricoles. Une enqu\ueate de terrain a \ue9t\ue9 r\ue9alis\ue9e dans la Commune de Dano aupr\ue8s de 158 producteurs rizicoles. Le questionnaire a port\ue9 sur les caract\ue9ristiques sociod\ue9mographiques des producteurs rizicoles, les types de pesticides utilis\ue9s et leurs effets sur la sant\ue9. L\u2019\ue9tude montre que la riziculture \ue0 Dano est une activit\ue9 principalement exerc\ue9e par une population vieillissante dont les plus de 50 ans repr\ue9sentent pr\ue8s de 60%. De plus, la population est analphab\ue8te \ue0 61% contre 32% des producteurs ayant fr\ue9quent\ue9 l\u2019\ue9cole primaire. Les mauvaises pratiques d\u2019utilisation des pesticides sont fr\ue9quentes et concernent surtout l\u2019insuffisance des \ue9quipements de protection individuels des producteurs, les pratiques de stockage et de r\ue9utilisation des reliquats de pesticides. Douze types de pesticides ont \ue9t\ue9 identifi\ue9s dont 40% ne sont pas homologu\ue9s. Les principales mati\ue8res actives dans les herbicides sont le Glyphosate, le Paraquat, le Bensulfuron methyl et le Bispyribac-sodium. Les effets sanitaires de l\u2019utilisation des pesticides sont ressentis par les producteurs agricoles \ue0 travers divers sympt\uf4mes des intoxications. Pour r\ue9duire la pr\ue9valence des intoxications aux pesticides, des campagnes d\u2019information et de sensibilisation doivent \ueatre men\ue9es \ue0 l\u2019endroit des populations et des producteurs pour une utilisation s\ue9curis\ue9e des pesticides

Impact of IYCF practices, as measured by national nutrition surveys from 2018 to 2022, on stunting and under-5 survival in Burkina Faso: a LiST analysis

IntroductionBurkina Faso is facing a serious public health problem of chronic malnutrition and mortality in children under the age of 5. To tackle this situation, a number of child nutrition interventions have been implemented. This study aims to assess the impact of these interventions on the nutritional status of children aged 0–5 years between 2018 and 2022.MethodsThis study is a modeling of the impact of changes in the coverage of interventions with known effect sizes, using the LiST (Lives Saved Tool). The interventions used concern infant and young child feeding, the coverage of which was measured by the 2018 to 2022 editions of the NNS conducted in Burkina Faso using the SMART methodology. It covered the national level, the Center region and the Sahel region. Extracted intervention coverage levels were entered into LiST, according to six projections in two scenarios (scenario 1 and 2). The modeling results visualized in LiST were exported to Excel for formatting into tables and/or graphs.ResultsThe measured changes in the levels of infant and young child feeding interventions included in this study led to a reduction in the number of cases of chronic malnutrition in children under 6 months of age in the second scenario projections. However, no cases of chronic malnutrition were prevented among children in the 6–59 month age group under any of the six projections. On the contrary, opportunities to save cases of chronic malnutrition have been missed. These missed opportunities amount to 64,880 in scenario 1 and 39,556 in scenario 2 at national level. Nevertheless, 920 lives were saved nationwide, 232 in the Center region and 202 in the Sahel region.ConclusionThe study highlighted the need to strengthen the implementation of IYCF interventions, coupled with a significant improvement in the quality of NNS data collection, given the up and down nature of the indicators, which makes them difficult to use for decision-making

Molecular diagnosis of Shigella, Salmonella and Campylobacter by multiplex Real-time PCR in stool culture samples in Ouagadougou (Burkina Faso)

ABSTRACT:Background: Bacteriological diagnosis of Campylobacter spp, Salmonella spp and Shigella spp could be necessary in the case of infectious gastroenteritis syndrome.The objective of this study was to diagnose concomitantly the three enteropathogenic bacteria by multiplex Real-Time PCR in stool culture samples in Ouagadougou (Burkina Faso).Materials and Methods: The study was conducted from February 5th to March 9th, 2013. Two hundred stool samples were received during the study period. The bacteria were identified by bacterial culture following by multiplex Real-Time PCR.Results: Shigella spp and Campylobacter spp were sought by culture in all 200 samples. Enteropathogenic E. coli was sought only in 37 samples from all children under 2 years old. The bacterial culture was positive in 12 stool samples. Shigella spp and Salmonella spp. were isolated respectively in 5 (2.5%) and 3 samples (1.5%). Enteropathogenic E. coli was isolated in 10.8% (4/37) of the samples tested.The multiplex real-time PCR identified bacteria in 20 patients, including 17 cases of Shigella spp., 1 case of Salmonella spp. and 2 cases of Campylobacter spp.Conclusions: This study has highlighted the low frequency of 3 sought bacterial genera in stool samples. It has also demonstrated a significant difference between the culture and the multiplex Real-Time PCR method in the diagnosis of Shigella

A Randomized Trial to Assess the Impact of a Package of Diagnostic Tools and Diagnostic Algorithm on Antibiotic Prescriptions for the Management of Febrile Illnesses Among Children and Adolescents in Primary Health Facilities in Burkina Faso.

BACKGROUND: Low- and middle-income countries face significant challenges in differentiating bacterial from viral causes of febrile illnesses, leading to inappropriate use of antibiotics. This trial aimed to evaluate the impact of an intervention package comprising diagnostic tests, a diagnostic algorithm, and a training-and-communication package on antibiotic prescriptions and clinical outcomes. METHODS: Patients aged 6 months to 18 years with fever or history of fever within the past 7 days with no focus, or a suspected respiratory tract infection, arriving at 2 health facilities were randomized to either the intervention package or standard practice. The primary outcomes were the proportions of patients who recovered at day 7 (D7) and patients prescribed antibiotics at day 0. RESULTS: Of 1718 patients randomized, 1681 (97.8%; intervention: 844; control: 837) completed follow-up: 99.5% recovered at D7 in the intervention arm versus 100% in standard practice (P = .135). Antibiotics were prescribed to 40.6% of patients in the intervention group versus 57.5% in the control arm (risk ratio: 29.3%; 95% CI: 21.8-36.0%; risk difference [RD]: -16.8%; 95% CI: -21.7% to -12.0%; P < .001), which translates to 1 additional antibiotic prescription saved every 6 (95% CI: 5-8) consultations. This reduction was significant regardless of test results for malaria, but was greater in patients without malaria (RD: -46.0%; -54.7% to -37.4%; P < .001), those with a respiratory diagnosis (RD: -38.2%; -43.8% to -32.6%; P < .001), and in children 6-59 months old (RD: -20.4%; -26.0% to -14.9%; P < .001). Except for the period July-September, the reduction was consistent across the other quarters (P < .001). CONCLUSIONS: The implementation of the package can reduce inappropriate antibiotic prescription without compromising clinical outcomes. CLINICAL TRIALS REGISTRATION: clinicaltrials.gov; NCT04081051

Safety and efficacy of malaria vaccine candidate R21/Matrix-M in African children: a multicentre, double-blind, randomised, phase 3 trial

Background Recently, we found that a new malaria vaccine, R21/Matrix-M, had over 75% efficacy against clinical malaria with seasonal administration in a phase 2b trial in Burkina Faso. Here, we report on safety and efficacy of the vaccine in a phase 3 trial enrolling over 4800 children across four countries followed for up to 18 months at seasonal sites and 12 months at standard sites. Methods We did a double-blind, randomised, phase 3 trial of the R21/Matrix-M malaria vaccine across five sites in four African countries with differing malaria transmission intensities and seasonality. Children (aged 5–36 months) were enrolled and randomly assigned (2:1) to receive 5 μg R21 plus 50 μg Matrix-M or a control vaccine (licensed rabies vaccine [Abhayrab]). Participants, their families, investigators, laboratory teams, and the local study team were masked to treatment. Vaccines were administered as three doses, 4 weeks apart, with a booster administered 12 months after the third dose. Half of the children were recruited at two sites with seasonal malaria transmission and the remainder at standard sites with perennial malaria transmission using age-based immunisation. The primary objective was protective efficacy of R21/Matrix-M from 14 days after third vaccination to 12 months after completion of the primary series at seasonal and standard sites separately as co-primary endpoints. Vaccine efficacy against multiple malaria episodes and severe malaria, as well as safety and immunogenicity, were also assessed. This trial is registered on ClinicalTrials.gov, NCT04704830, and is ongoing. Findings From April 26, 2021, to Jan 12, 2022, 5477 children consented to be screened, of whom 1705 were randomly assigned to control vaccine and 3434 to R21/Matrix-M; 4878 participants received the first dose of vaccine. 3103 participants in the R21/Matrix-M group and 1541 participants in the control group were included in the modified per-protocol analysis (2412 [51·9%] male and 2232 [48·1%] female). R21/Matrix-M vaccine was well tolerated, with injection site pain (301 [18·6%] of 1615 participants) and fever (754 [46·7%] of 1615 participants) as the most frequent adverse events. Number of adverse events of special interest and serious adverse events did not significantly differ between the vaccine groups. There were no treatment-related deaths. 12-month vaccine efficacy was 75% (95% CI 71–79; p<0·0001) at the seasonal sites and 68% (61–74; p<0·0001) at the standard sites for time to first clinical malaria episode. Similarly, vaccine efficacy against multiple clinical malaria episodes was 75% (71–78; p<0·0001) at the seasonal sites and 67% (59–73; p<0·0001) at standard sites. A modest reduction in vaccine efficacy was observed over the first 12 months of follow-up, of similar size at seasonal and standard sites. A rate reduction of 868 (95% CI 762–974) cases per 1000 children-years at seasonal sites and 296 (231–362) at standard sites occurred over 12 months. Vaccine-induced antibodies against the conserved central Asn-Ala-Asn-Pro (NANP) repeat sequence of circumsporozoite protein correlated with vaccine efficacy. Higher NANP-specific antibody titres were observed in the 5–17 month age group compared with 18–36 month age group, and the younger age group had the highest 12-month vaccine efficacy on time to first clinical malaria episode at seasonal (79% [95% CI 73–84]; p<0·001) and standard (75% [65–83]; p<0·001) sites. Interpretation R21/Matrix-M was well tolerated and offered high efficacy against clinical malaria in African children. This low-cost, high-efficacy vaccine is already licensed by several African countries, and recently received a WHO policy recommendation and prequalification, offering large-scale supply to help reduce the great burden of malaria in sub-Saharan Africa. Funding The Serum Institute of India, the Wellcome Trust, the UK National Institute for Health Research Oxford Biomedical Research Centre, and Open Philanthropy