Contamination fongique des fourrages consommes par les aulacodes (Thryonomys swinderianus) d’elevage en zone periurbaine d’Abidjan (Côte d’Ivoire)

Le fourrage prélevé dans les zones urbaines et périurbaines est de plus en plus utilisé dans l’alimentation des herbivores domestiques, en général, et de l’Aulacode, en particulier. Ce fourrage souvent en contact avec des déchets ménagers pourrait être contaminé par les spores fongiques decet environnement. L’objectif général de cette étude consistait à évaluer quelques risques sanitaires que court l’homme en consommant la viande d’Aulacode nourris au fourrage urbain et périurbain. L’objectif spécifique était d’identifier les genres fongiques retrouvés sur deux espèces  fourragères (Panicum maximum et Pueraria phaseoloïdes) fréquemment utilisées par les aulacodiers pour nourrir leurs animaux. Pour atteindre cet objectif, des fragments de fourrage ont été mis en culture sur le milieu Potato Dextrose Agar (PDA) en vue de déceler d’éventuels  microorganismes. Cette étude a permis de relever la présence de quatre genres de moisissure : Aspergillus, Alternaria, Penicillium et Fusarium. Certaines espèces appartenant à ces genres sont généralement   impliquées dans des mycoses chez les animaux et des maladies  fongiques chez les végétaux. Ainsi, les genres Aspergillus et Fusarium sont respectivement zoonotique et immunosuppresseur qui constitue un risque pour les collecteurs de fourrage et les éleveurs.Mots clés : Moisissure, contamination, Panicum, Pueraria, Aulacode

Etude du comportement morphologique sous deficit hydrique de categories de palmier a huile(Elaeis guineensis Jacq.) en phase juvenile

L’une des voies préconisées pour augmenter la production de l’huile de palme est l’élargissement de l’espace culturale du palmier à huile. L’élargissement de ce espace culturale va conduire à exploiter les zones à déficit hydrique. Il devient nécessaire de détecter des catégories de palmiercapables de réaliser leur cycle dans ces zones de culture. Le matériel de l’essai réalisé à la station de la Me se compose de 150 plants de 4 mois, de 5 catégories de palmier. Le schéma expérimental est un bloc de Fisher de deux facteurs à cinq niveaux différents : le matériel végétal (5 catégories) et les traitements hydriques (5 traitements) durant 45 jours sous serre. La valeur témoin de 725 ml est la capacité de rétention en eau de 3500 g de terre d’un sachet. Les déficits hydriques sont obtenus par la réduction graduelle de la valeur témoin : 725ml (100 %), 544 ml (75 %), 363 ml (50 %), 73 ml (10 %). Les paramètres étudiés (longueur racine, poids, hauteur et circonférence au collet des plants) ont été affectés à chaque niveau de déficit hydrique. Aux sévères déficits, la baisse du poids, la hauteur et la circonférence au collet des catégories en comparaison avec le témoin est élevée pour C1001, C2501, faible pour C1001F, C2401, C7001. L’adaptation des racines aux sévères déficits est développée chez C1001F, C2401, C7001. L’analyse de la variation des valeurs des paramètres montre une bonne tolérance au déficit hydrique des catégories C1001F, C7001, C2401.Cette étude permettant de distinguer  morphologiquement des catégories tolérantes au déficit hydrique, sertd’étude préliminaire à la détection de catégories tolérantes au déficit  hydrique.Mots clés : Elaeis guineensis, déficit hydrique, tolérance, poids, racine, hauteur, circonférence au collet. English Title: Morphological behavior under water deficit of five categories of oil palm (Eleais guineensis jacq</i>.) in the juvenile phaseThe climatic factors such as insufficient rainfall limit the cultivation of oil palm. It is therefore important for the stability of elaeis culture to detect at a young age, categories of palms tolerant to drought. The material in our research consists of 150 seedlings of 4 months, come from five categories of palms. The experimental set-up is a Fisher block allowing the study of two factors at five different levels : plant material (five categories) and water treatments (5 treatments) during a period of 45 days under a greenhouse. The witness value of 725 ml is the water retention capacity of 3500 g of soil of a sachet. Water deficits are obtained by the gradual reduction of the control value : 725 ml (100%), 544 ml (75%), 363 ml (50%), 181 ml (25%), 73 ml (10%). The parameters studied (weight, root, height, collar circumference of plants) were assigned to each level of water deficit. At severe water deficit, the weight losses, The reduction of the height and the circumferentiel collar are high in the C1001 and C 2501and weak for the C 1001F, C 2401 and C 7001 category. Root adaptation to severe deficits is developed in C 1001F, C 2401, C 7001. The analysis of the variations of the values of the parameters under the action of the water stress showed us that the categories C1001F, C 7001 and C 2401 had a fairly developed a tolerance to the water deficit. These results are interest because they make it possible at young age to morphologically distinguish categories that are tolerant to drought.Key words: Elaeis guineensis, oil palm, water deficit, categories, parameter, weight, root, growth, collar circumference

Structural and transcriptional analysis of plant genes encoding the bifunctional lysine ketoglutarate reductase saccharopine dehydrogenase enzyme

<p>Abstract</p> <p>Background</p> <p>Among the dietary essential amino acids, the most severely limiting in the cereals is lysine. Since cereals make up half of the human diet, lysine limitation has quality/nutritional consequences. The breakdown of lysine is controlled mainly by the catabolic bifunctional enzyme lysine ketoglutarate reductase - saccharopine dehydrogenase (LKR/SDH). The LKR/SDH gene has been reported to produce transcripts for the bifunctional enzyme and separate monofunctional transcripts. In addition to lysine metabolism, this gene has been implicated in a number of metabolic and developmental pathways, which along with its production of multiple transcript types and complex exon/intron structure suggest an important node in plant metabolism. Understanding more about the LKR/SDH gene is thus interesting both from applied standpoint and for basic plant metabolism.</p> <p>Results</p> <p>The current report describes a wheat genomic fragment containing an LKR/SDH gene and adjacent genes. The wheat LKR/SDH genomic segment was found to originate from the A-genome of wheat, and EST analysis indicates all three LKR/SDH genes in hexaploid wheat are transcriptionally active. A comparison of a set of plant LKR/SDH genes suggests regions of greater sequence conservation likely related to critical enzymatic functions and metabolic controls. Although most plants contain only a single LKR/SDH gene per genome, poplar contains at least two functional bifunctional genes in addition to a monofunctional LKR gene. Analysis of ESTs finds evidence for monofunctional LKR transcripts in switchgrass, and monofunctional SDH transcripts in wheat, <it>Brachypodium</it>, and poplar.</p> <p>Conclusions</p> <p>The analysis of a wheat LKR/SDH gene and comparative structural and functional analyses among available plant genes provides new information on this important gene. Both the structure of the LKR/SDH gene and the immediately adjacent genes show lineage-specific differences between monocots and dicots, and findings suggest variation in activity of LKR/SDH genes among plants. Although most plant genomes seem to contain a single conserved LKR/SDH gene per genome, poplar possesses multiple contiguous genes. A preponderance of SDH transcripts suggests the LKR region may be more rate-limiting. Only switchgrass has EST evidence for LKR monofunctional transcripts. Evidence for monofunctional SDH transcripts shows a novel intron in wheat, <it>Brachypodium</it>, and poplar.</p

Évaluation de la sensibilité de sept clones de palmier à huile (Elaeis guineensis Jacq.) à Coelaenomenodera lameensis Berti et Mariau (Coleoptera, Chrysomelidae) Konan J.

Objectifs : Évaluer la sensibilité de 7 clones d’Elaeis guineensis à Coelaenomenodera lameensis (Coleoptera : Hispinae) et estimer les dégâts occasionnés par l’insecte au terme d’un cycle de développement complet sur chaque type de matériel clonal.Méthodologies et Résultats : des insectes adultes de C. lameensis ont été transposés sur des folioles de clones d’Elaeis guineensis isolés dans des manchons. L’évolution des insectes a été ensuite observée à chaque étape du cycle normal de développement de C. lameensis. Les dégâts provoqués par l’insecte ont été estimés par le rapport entre la surface de foliole attaquée et la surface totale de foliole. Les résultats ont montré que certains clones étaient moins favorables au développement de l’insecte que d’autres. Le clone LMC247, avec 53,80 % ± 2,56 de surface foliaire attaquée, a été plus sensible à l’insecte que les autres clones LMC159, LMC161, LMC022, LMC010, LMC270 et LMC291 où les dégâts observés ont été en dessous de 25%..Conclusion et Application : au regard des résultats, il ressort que le développement de C. lameensis est influencé par le type de matériel clonal. Les dégâts sur les clones testés ont été généralement de faible intensité. Cette approche expérimentale, laisse présager de bonnes perspectives pour la lutte génétique contre C. lameensis.. En effet, plus de 300 clones de palmier ont déjà été crées en Côte d’Ivoire. Un criblage élargi à l’ensemble de ce matériel va permettre d’identifier à terme des clones performants pour contrôler le ravageur, au regard de l’homogénéité de ce type de matériel végétal.Mots clés : clone, palmier à huile, lutte génétique, Coelænomenodera lameensisEvaluation of seven oil palm clones (Elaeis guineensis Jacq.) sensibility to Coelaenomenodera lameensis Berti and Mariau (Coleoptera, Chrysomelidae)Objective: this study aims to evaluate seven oil palm clones sensibility to Coelaenomenodera lameensis (Coleoptera: Hispinae) and to estimate the damage caused by this insect on each type of clonal material.Methods and results: adult insects of C. lameensis were transposed on Elaeis guineensis clones leaflets isolated in canvas bags. Insect evolution was observed at each stage of normal development cycle of C. lameensis. The damage caused by the insect was estimated using the ratio of the surface of leaflet attacked and the total surface of leaflet. The results showed that some clones were less favorable to the development of C. lameensis than others. The clone LMC247, with 53.80 ± 2.56% of leaf surface attacked was more susceptible to C. lameensis than the other clones LMC159, LMC161, LMC022, LMC010, LMC270 and LMC291. For these clones, the damages noted were below 25% of leaf area attacked.Conclusion and application: the results showed that C. lameensis development depended of the clones. Overall, a low intensity of damage was observed on the leaflet of the clones. This experimental approach suggests good projection for genetic control of C. lameensis with oil palm clone material. Indeed, more than 300 oil palm clones have already been established in Côte d'Ivoire. The screening of this material can help selecting performing material to control the pest due to the homogeneity of this type of plant material. Key words: clone, oil palm, genetic control, Coelænomenodera lameensi

Hepatoprotective and antioxidant activities of Hibiscus sabdariffa petal extracts in Wistar rats

Background: Hibiscus sabdariffa is a medicinal plant rich in phytochemical compounds, which is the source of its biological properties. This study on the aqueous extract of H. sabdariffa (AEHS) was conducted to assess its hepatoprotective and antioxidant properties.Methods: It was carried out with 25 Wistar rats divided into five groups. Two groups were treated with a solution of NaCl 0.9%. One group was treated with silymarin at a dose of 25 mg/kg body weight (BW). Two other groups were treated with the AEHS at different doses (100 and 200 mg/kg BW). The treatments were carried out via oral route and at single dose for 7 days. After injection of 2,4-dinitrophenylhydrazine (DNPH), blood samples were collected for the carrying out of biochemical analyses of oxidative stress markers (thiobarbituric acid reactive substances, ferric reduction antioxidant parameter, and 2,2-diphenyl-1-picrylhydrazyl) and hepatotoxicity (albumin, total and direct bilirubin, alanine transaminase, aspartate aminotransferase, and lactate dehydrogenase).Results: Three major results were obtained. The hepatotoxicity of DNPH expressed by the rats of Group 1 was significantly different (p<0.05) from those of the other groups (control, 2-4) for both hepatotoxicity and oxidative stress markers. The hepatoprotective and antioxidant properties of the AEHS and confirmation of those of silymarin through the rats of Groups 2-4 were statistically identical (p<0.05) to the control group for markers of hepatotoxicity and oxidative stress.Conclusion: These results confirm and reinforce certain therapeutic virtues of H. sabdariffa

Large-scale field trial of attractive toxic sugar baits (ATSB) for the control of malaria vector mosquitoes in Mali, West Africa.

BACKGROUND: The aim of this field trial was to evaluate the efficacy of attractive toxic sugar baits (ATSB) in Mali, where sustained malaria transmission occurs despite the use of long-lasting insecticidal nets (LLINs). ATSB bait stations were deployed in seven of 14 similar study villages, where LLINs were already in widespread use. The combined use of ATSB and LLINs was tested to see if it would substantially reduce parasite transmission by Anopheles gambiae sensu lato beyond use of LLINs alone. METHODS: A 2-day field experiment was conducted to determine the number of mosquitoes feeding on natural sugar versus those feeding on bait stations containing attractive sugar bait without toxin (ASB)-but with food dye. This was done each month in seven random villages from April to December 2016. In the following year, in seven treatment villages from May to December 2017, two ATSB bait stations containing the insecticide dinotefuran were placed on the outer walls of each building. Vector population density was evaluated monthly by CDC UV light traps, malaise traps, pyrethrum spray (PSCs) and human landing catches (HLCs). Female samples of the catch were tested for age by examination of the ovarioles in dissected ovaries and identification of Plasmodium falciparum sporozoite infection by ELISA. Entomological inoculation rates (EIR) were calculated, and reductions between treated and untreated villages were determined. RESULTS: In the 2-day experiment with ASB each month, there was a lower number of male and female mosquitoes feeding on the natural sugar sources than on the ASB. ATSB deployment reduced CDC-UV trap female catches in September, when catches were highest, were by 57.4% compared to catches in control sites. Similarly, malaise trap catches showed a 44.3% reduction of females in August and PSC catches of females were reduced by 48.7% in September. Reductions of females in HLCs were lower by 19.8% indoors and 26.3% outdoors in September. The high reduction seen in the rainy season was similar for males and reductions in population density for both males and females were > 70% during the dry season. Reductions of females with ≥ 3 gonotrophic cycles were recorded every month amounting to 97.1% in October and 100.0% in December. Reductions in monthly EIRs ranged from 77.76 to 100.00% indoors and 84.95% to 100.00% outdoors. The number of sporozoite infected females from traps was reduced by 97.83% at treated villages compared to controls. CONCLUSIONS: Attractive toxic sugar baits used against Anopheles mosquitoes in Mali drastically reduced the density of mosquitoes, the number of older females, the number of sporozoite infected females and the EIR demonstrating how ATSB significantly reduces malaria parasite transmission

Dynamics of antigenemia and transmission intensity of Wuchereria bancrofti following cessation of mass drug administration in a formerly highly endemic region of Mali

Background After seven annual rounds of mass drug administration (MDA) in six Malian villages highly endemic for Wuchereria bancrofti (overall prevalence rate of 42.7%), treatment was discontinued in 2008. Surveillance was performed over the ensuing 5 years to detect recrudescence. Methods Circulating filarial antigen (CFA) was measured using immunochromatographic card tests (ICT) and Og4C3 ELISA in 6–7 year-olds. Antibody to the W. bancrofti infective larval stage (L3) antigen, Wb123, was tested in the same population in 2012. Microfilaraemia was assessed in ICT-positive subjects. Anopheles gambiae complex specimens were collected monthly using human landing catch (HLC) and pyrethrum spray catch (PSC). Anopheles gambiae complex infection with W. bancrofti was determined by dissection and reverse transcriptase polymerase chain reaction (RT-PCR) of mosquito pools. Results Annual CFA prevalence rates using ICT in children increased over time from 0% (0/289) in 2009 to 2.7% (8/301) in 2011, 3.9% (11/285) in 2012 and 4.5% (14/309) in 2013 (trend χ 2  = 11.85, df =3, P = 0.0006). Wb123 antibody positivity rates in 2013 were similar to the CFA prevalence by ELISA (5/285). Although two W. bancrofti-infected Anopheles were observed by dissection among 12,951 mosquitoes collected by HLC, none had L3 larvae when tested by L3-specific RT-PCR. No positive pools were detected among the mosquitoes collected by pyrethrum spray catch. Whereas ICT in 6–7 year-olds was the major surveillance tool, ICT positivity was also assessed in older children and adults (8–65 years old). CFA prevalence decreased in this group from 4.9% (39/800) to 3.5% (28/795) and 2.8% (50/1,812) in 2009, 2011 and 2012, respectively (trend χ 2  = 7.361, df =2, P = 0.0067). Some ICT-positive individuals were microfilaraemic in 2009 [2.6% (1/39)] and 2011 [8.3% (3/36)], but none were positive in 2012 or 2013. Conclusion Although ICT rates in children increased over the 5-year surveillance period, the decrease in ICT prevalence in the older group suggests a reduction in transmission intensity. This was consistent with the failure to detect infective mosquitoes or microfilaraemia. The threshold of ICT positivity in children may need to be re-assessed and other adjunct surveillance tools considered