Caractérisation physico-chimique de l’eau des noix matures de nouveaux hybrides améliorés de cocotiers (Cocos nucifera L.) grands

Des hybrides améliorés de cocotiers grands ont été créés par la Station de recherche Marc Delorme en vue de satisfaire les préférences des grosses noix des acteurs de la filière cocotier. Cependant ils demeurent encore peu étudiés. Le présent travail évalue les caractéristiques physicochimiques de l’eau des noix matures de ces nouveaux hybrides en vue d’en proposer des voies de valorisation. Les travaux portent sur des noix âgées de treize mois (rang 25) d’hybrides de cocotiers grands GPY+ x GOA+, GPY+ x GRL+ et GRL+ x GOA+ en comparaison avec l’hybride PB121+, pris comme témoin. La masse des noix entières et de l’eau de coco ont été déterminés moins de 24 h après la récolte des noix de coco. Puis des échantillons d’eau de coco ont été prélevés et conservés à -15 °C avant leurs caractérisations. Les résultats ont montré que l’eau de coco mature est plus abondante et plus acide chez les hybrides améliorés de cocotiers grands que chez le PB121+. Parmi les trois hybrides grands améliorés, GRL+ x GOA+ fournit l’eau de coco mature la plus pourvue en cendres (0,49%). Les hybrides GPY+ x GOA+ et GPY+ x GRL+ renferment plus de sucres (29,37 et 28,09 mg/ml) et de polyphénols (58,11 et 65,49 ppm). Il ressort de ces études que l’eau des noix matures de ces hybrides pourrait être utilisée pour la production d’alcool éthylique et de vinaigre.Mots clés : Valorisation, eau de coco, caractéristiques, vinaigre, alcool, Côte d’Ivoir

Caractéristiques gustatives de l’eau des fruits de quatre cultivars du cocotier (Cocos nucifera L.)

Les caractéristiques gustatives (descriptives et hédoniques) de l’eau des fruits de quatre cultivars du cocotier (Cocos nucifera L.) ont été étudiées au cours de la maturation des noix. Il s’est agi du Grand OuestAfricain, du Nain Jaune de Malaisie, du Nain Vert de Guinée Equatoriale et de l’hybride PB121 amélioré. Les paramètres testés ont été les saveurs (sucrée, salée et acide) et les préférences gustatives. Les résultats obtenus ont montré des interactions significatives entre les cultivars et les stades de maturité pour les paramètres analysés. Ainsi, au cours de la maturation des noix, la saveur sucrée de l’eau de coco est prédominante quel que soit le stade de maturité. Elle est maximale chez les cultivars nains de rang 21 avec des perceptions équivalant à des teneurs en sucres de 5,80 à 6,10%. A maturité, la saveur sucrée de l’eau de coco baisse car les sucres interviennent dans la formation de l’amande. Les résultats des tests hédoniques ont abouti à la préférence de l’eau de coco en fonction de son goût sucré. Ainsi, l’eau des noix immatures des cultivars nains a été la plus appréciée. Cette étude a permis de déterminer les caractéristiques sensorielles de l’eau de coco afin de fournir des indicateurs pour une valorisation technologique efficiente.Mots clés: Eau de coco, tests sensoriels, cultivars, maturation

Laboratory study of the biology and behaviour of Diplonychus sp (Belostomatidae) and its vector competence in the transmission to humans of Mycobacterium ulcerans, the pathogen causing Buruli ulcer in Côte d’Ivoire (West Africa).

Buruli ulcer is a skin infection caused by a mycobacterium occurring in the environment, Mycobacterium ulcerans.  Ranked third in terms of number of mycobacterial infections after leprosy and tuberculosis, its epidemiology is the most poorly understood of the three. Humans are infected through the skin while performing daily living activities (e.g. rice cultivation, fish farming, fishing, laundry, fetching water, agricultural work) or leisure activities (e.g. bathing) in endemic areas. The disease is particularly prevalent in West Africa, where the number of cases is increasing annually (2442 cases in 2008). Côte d’Ivoire is the most severely affected country in the world with more than 25 000 cases since 1978. The numerous endemic foci for Buruli ulcer are scattered throughout the country. Over the past four years impressive progress has been made in researching the mode of transmission of M. ulcerans infection. Yet despite this, many questions remain unanswered. In Central and West Africa aquatic insects of the order Hemiptera appear to be involved in the transmission of Buruli ulcer.  It is likely that aquatic Hemiptera play a role.  Studies of the salivary glands of insects that have been experimentally infected and allowed to bite white mice demonstrate the probable role of water bugs as hosts or possible vectors of M. ulcerans. In addition, at least 10% of environmental biological specimens tested positive using PCR in Cameroon and Côte d’Ivoire. These pterygot insects are also able to fly from one body of water to another over varying distances, attracted by lights in houses near marshy areas. This method of displacement could account for the current progression of the disease in West Africa and particularly in Côte d’Ivoire, where it is spreading northwards from the south, west, east and centre of the country.   Buruli ulcer is not a contagious disease.  It is, however, terrifying and severely disabling.  Patients must spend long periods in hospital, treatment is costly and burdensome, and can lead to social marginalization or even total exclusion; above all, the mode of transmission is still poorly understood.  Local people must therefore be familiarized with preventive measures focusing on identification of the probable vectors of the disease in order to break the chain of transmission of M. ulcerans. This presupposes a sound knowledge of the biology, ecology and behaviour of these potential vectors. Accordingly, we have proceeded to laboratory farm the bug most commonly encountered in the environment that shows the highest rates of infection by M. ulcerans (more than 10%), namely Diplonychus sp of the family Belostomatidae. Adult specimens were collected in the vicinity of fishponds at an experimental station situated between Abidjan and Dabou (a non-endemic site) and subsequently farmed in the laboratory at the Côte d’Ivoire National Institute of Public Health. The parameters used to farm this water bug were standardized in the laboratory (water quality, depth, turbidity, pH, temperature, luminosity, suitable vegetable environment). The insects were fed regularly with mosquito larvae. The embryonic lifespan, the hatching time, the larval period and the number of larval stages prior to adulthood were studied. The adult lifespan was also estimated. Five successive generations of Diplonychus sp were obtained. From egg to adulthood, the larval lifespan is 41 days on average, with deviations from the mean of 29 to 54 days.  Hatching generally took place 7 days after egg laying.  Five larval stages are distinguishable, separated by five metamorphoses.  The lifespan of certain adults obtained in the laboratory varied between 16 and 150 days.  The last original parental specimens survived for 11 months.  Proficiency in the laboratory farming of Diplonychus sp could enable us to decode its genome and collect saliva samples, while also allowing us to perform experimental infections using human strains of M. ulcerans in order to confirm or rule out the involvement of this insect in the transmission of Buruli ulcer in Central and West Africa

Décomposition des tourteaux de coprah et de palmiste et effets sur la croissance des cocotiers (Cocos nucifera L.) en pépinière et la nutrition minérale des cocotiers adultes en Côte-d\'Ivoire

L\'objectif de cette étude est d\'évaluer le potentiel fertilisant des tourteaux de coprah et de palmiste. Ainsi, les tourteaux ont été mis en décomposition pendant une période de 12 mois. Leurs effets sur la croissance des jeunes cocotiers ont été étudiés pendant 9 mois en comparaison à ceux de l\'engrais chimique. Une analyse foliaire a été réalisée afin d\'évaluer les effets des tourteaux sur la nutrition minérale des cocotiers adultes, 7 et 21 mois après leur épandage. Après 12 mois, les tourteaux ont libéré la totalité du potassium et plus de la moitié de l\'azote et du phosphore. Ils ont eu un effet positif sur la croissance des cocotiers en pépinière semblable à celui de la fumure chimique composée d\'urée à 46 % de N, super phosphate simple à 18 % de P2O5, chlorure de potassium à 60 % de K2O et de kiesérite à 28 % de MgO. Sept mois après l\'épandage, ils ont amélioré les teneurs foliaires en azote, en phosphore et en potassium des cocotiers adultes, mais ces teneurs ont chuté 21 mois après. Ces résultats montrent que les tourteaux sont des engrais organiques qui pourraient remplacer la fumure chimique.The objective of this study is to assess the fertilizing potential of the oil-cakes of copra and palm tree. Thus, the oilcakes were allowed to decompose for 12 months period. Their effects on the growth of young coconuts were studied for 9 months in comparison with those of chemical fertilisers. A foliar analysis was carried out in order to assess the effects of the oil-cakes on the mineral nutrition of adult coconuts 7 and 21 month after application. After 12 months, the oil-cakes released the totality of the potassium and more than half of nitrogen and phosphorus. Application of oil-cakes had a positive effect on the growth of coconuts in nursery similar to the one of the chemical fertilizer, consisted of urea (46 % of N), super simple phosphorus (18 % of P2O5), potassium chloride (60 % of K2O) and kieserite (28 % of MgO). Seven months after application, they improved the foliar contents of nitrogen, phosphorus and potassium of adult coconuts, but these contents fell 21 month later. These results show that the oil-cakes may be used as organic fertilizers that could replace the chemical fertilizers. Keywords: Coconut, nitrogen, potassium, mineral nutrition, phosphorus, oil-cakes.Sciences & Nature Vol. 5 (2) 2008: pp. 155-16

Macroinvertebrate Communities Associated with Hydrilla verticillata (Royle, 1839) and Relationship with Environmental Factors in Ono Lagoon, Southeast of Côte d’Ivoire

The macroinvertebrates associated with Hydrilla verticillata was studied in Ono lagoon, South-eastern of Côte d'Ivoire. Monthly samples of macrophytes with their associated macroinvertebrates were collected in upstream, centre and downstreamusing a Van veen grab of 0.314 m2 internal area. The environmental variables (temperature, transparency, depth, conductivity, TDS, pH, dissolved oxygen, , , and ) were also recorded. A total of 71 taxa belonging to 28 families, 11 orders, 05 classes and 03 phyla of which 40 taxa were recorded in upstream, 45 taxa in centre and 44 taxa in downstream. Insects numerically dominated the capture, comprising 91.55% of the collectedtaxa with Odonata and Coleoptera being the most diverse and abundant groups. The density was higher in upstream (1407ind. per 100 g d.w.) and lower in downstream (1062 ind. per 100 g d.w.), whist theLibellulidae and Corduliidae exhibited the highest density communities. The rarefied richness did not show spatial variation but vary significantly between seasons. The Evenness did not show spatial and seasonal variations. However, Shannon diversity index varied significantly between sites and seasons. From the results of RDA analysis, conductivity and pH showed a strong environmental gradient and had a structuring effect on macroinvertebrate communities

Entomological investigations carried out from 2002 to 2010 into the involvement of water bugs (Heteroptera - Hemiptera) in transmission of Mycobacterium ulcerans to humans in Côte d’Ivoire (West Africa)

Ulcer is a disease caused by a mycobacterium present in the environment: Mycobacterium ulcerans.This communicable disease occurs essentially in wet tropical regions, and in particular in west Africa where it is endemic. It is the third most common mycobacterial disease affecting humans after leprosy and tuberculosis, although it is more prevalent than either leprosy or tuberculosis in some rural areas of several countries (Benin, Côte d’Ivoire and Ghana). This has led WHO to act, and in 1998 to declare Buruli ulcer an « emerging disease » and to recognize it as a neglected tropical disease. Its development is a source of concern in Côte d’Ivoire, the country most affected in the world, with an aggregate number of 30 000 cases and more than 2000 cases detected each year. It particularly affects children living in isolated rural areas around bodies of stagnant or slowly flowing water.  In order to control the disease, it is essential fully to understand its epidemiology. In this connection, there are several hypotheses on the mode of transmission of M. ulcerans to humans. Since 1999, the involvement of water bugs belonging to the order of the hemiptera has been invoked by Portaels. In 2002, this hypothesis was confirmed by Marsollier et al. for water bugs of the genus Naucoris taken from the region of Daloa in Côte d’Ivoire, where the disease is endemic. In 2008, Portaels also found M. ulcerans in samples taken from the environment (Gerridae) in Ghana. In 2007, studies began in Côte d’Ivoire into the specific diversity, biology, ecology, ethology and role of aquatic heteroptera in the transmission of M. ulcerans to humans. Samples of aquatic heteroptera were collected each month from different aquatic environments in endemic areas of Côte d’Ivoire. The insects were identified by family, genus and occasionally species. Their distribution, population dynamics and ecological distribution in the water points investigated were correlated with human activities. Monospecific batches of water bugs were regularly composed in order to identify the molecular signatures of M. ulcerans using PCR at the bacteriology laboratory of the Institut Pasteur in Côte d’Ivoire and at the bacteriology laboratory of the Groupe d’Etudes des Interactions Hôtes-Pathogènes (Host-Pathogen Study Group) at the University Teaching hospital in Angers, France. Eighteen (18) species belonging to 8 families were identified. After the aquatic insects collected had been identified, 283 monospecific batches were composed and sent to the Institut Pasteur in Côte d’Ivoire (IPCI) for PCR. Twenty four (24) of the 283 batches i.e. 8,5% containing the following, 14 Diplonychus sp, 2 Naucoris sp, 3 Micronecta sp, 2 Ranatra fusca, 2 Anisops sp and 1 Laccotrephes ater, respectively belonging to the families Belostomatidae, Naucoridae, Corixidae, Ranatridae and Nepidae tested positive under PCR. Thirty five (35) samples of saliva were collected from specimens of the genus Diplonychus. Six of the samples (i.e. 17%) tested positive under PCR. Out of 109 other monospecific batches sent to the laboratory in Angers, France, 33 (i.e. 30%) tested positive under PCR. They comprised 11 batches of Diplonychus sp (Belostomatidae), 8 batches of Micronecta sp (Corixidae), 2 batches of Laccocoris sp (Naucoridae), 4 batches of Ranatra fusca (Ranatridae), 3 batches of Anisops sp, 1 lot de Anisops sardea et 1 lot de Enithares sp (Notonectidae), 2 batches of Plea pullula (Pleidae) and 1 batch of de Laccotrephes sp (Nepidae). Clearly, not only is Diplonychus sp the genus most commonly found, it is also that most affected by M. ulcerans. This justifies the decision to breed this genus in the laboratory since 2008, in order to improve our understanding of its biology and ethology and to standardize physical and chemical parameters so as to determine the best conditions for breeding the insect which would provide an animal model for experimental infections. We have now bred six successive generations in the laboratory. To conclude, although some aquatic heteroptera that host M. ulcerans are strictly phytophagous, (e.g. the Corixidae), the great majority of water bugs are carnivorous predators that are hosts and vectors of M. ulcerans. The absence of a reliable key for determining the family, genus and species in central and west Africa has led us to draw up an iconographic catalogue to determine the taxonomy of these insects

Antimicrobial susceptibility of extended-spectrum beta-lactamase producing Enterobacteriaceae causing urinary tract infections in Ouagadougou, Burkina Faso

Objective: To determine the frequency of extended-spectrum beta lactamase producing Enterobacteriaceae (ESBL) and other antibioticsresistant bacteria in urinary tract isolates.Study Design: prospective and experimental study.Methodology: Place and duration of study :YalgadoOuedraogo University Hospital Center, Charles De Gaulle Pediatric Hospital Center, Saint Camille Hospital and National Public Health Laboratory, Ouagadougou, from November 2014 to October 2015.AllEnterobacteriaceaestrains isolated from urinary samples of patients were identifiedusing API 20E chemical gallery (BioMerieux, France). All strains were subjected to an array of 14 antibiotics to study their drug susceptibility by using Kirby- Baeurdisk diffusion method. Detection of ESBL was carried out by double disk diffusion technique. Statistical analysis was performed by Microsoft Excel and Anova one-way GrapPad Prism version 5.01. Chi-square (χ2) test was used to determine significance. A p˂ 0.05was considered to be statistically significant.Results: A total of 324 isolates of Enterobacteriaceae were identified during the study period, including211(65%) E. coli, 75 (23%)Klebsiella spp., 18 (6%) Enterobacter spp., 11 (3%)Proteus spp., 5 (2%) Citrobacter spp., Serratia spp. 3 (1%).All the clinical isolates were susceptible to imipenem. Resistance to amikacinwas 14% (45/324); gentamicin 54% (175/324); tobramycin 58% (187/324); nalidixic acid 72% (234/324),ciprofloxacin 63% (204/324) and to cotrimoxazole 83% (269/324).The overall rate of the EBSL producing strains was 35% (114/324). Their susceptibility to antibiotics was (imipenem,amikacin, cefoxitin and fosfomycin) 100% (114/114), 93% (106/114), 74% (84/114) and 84% (96/114) respectively. ESBL positivity within individual organism group was highest inEscherichia coli 64% (73/324) followed byKlebsiellaspp. 28% (32/324), Enterobacterspp. 3% (4/324), Proteus spp. and Citrobacterspp. 2% (2/324).Conclusion: The results showeda high frequency of ESBL producing Enterobacteriaceae, especially Escherichia coli and Klebsiellaspp. The data points to theneed of routine detection and surveillance of ESBL producing bacteria in Burkina Faso.Keywords: Antimicrobial susceptibility, Enterobacteriaceae, Urine, Burkina Fas

Biodiversity and implication of waters bugs in transmission of Mycobacterium ulcerans, etiological agent of Buruli ulcer in Côte d’Ivoire (West Africa)

Date du colloque&nbsp;: 04/2009</p

Studies on Preparation of Photosensitizer Loaded Magnetic Silica Nanoparticles and Their Anti-Tumor Effects for Targeting Photodynamic Therapy

As a fast developing alternative of traditional therapeutics, photodynamic therapy (PDT) is an effective, noninvasive, nontoxic therapeutics for cancer, senile macular degeneration, and so on. But the efficacy of PDT was compromised by insufficient selectivity and low solubility. In this study, novel multifunctional silica-based magnetic nanoparticles (SMNPs) were strategically designed and prepared as targeting drug delivery system to achieve higher specificity and better solubility. 2,7,12,18-Tetramethyl-3,8-di-(1-propoxyethyl)-13,17-bis-(3-hydroxypropyl) porphyrin, shorted as PHPP, was used as photosensitizer, which was first synthesized by our lab with good PDT effects. Magnetite nanoparticles (Fe3O4) and PHPP were incorporated into silica nanoparticles by microemulsion and sol–gel methods. The prepared nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and fluorescence spectroscopy. The nanoparticles were approximately spherical with 20–30 nm diameter. Intense fluorescence of PHPP was monitored in the cytoplasm of SW480 cells. The nanoparticles possessed good biocompatibility and could generate singlet oxygen to cause remarkable photodynamic anti-tumor effects. These suggested that PHPP-SMNPs had great potential as effective drug delivery system in targeting photodynamic therapy, diagnostic magnetic resonance imaging and magnetic hyperthermia therapy

A Trial of Early Antiretrovirals and Isoniazid Preventive Therapy in Africa

BACKGROUND: In sub-Saharan Africa, the burden of human immunodeficiency virus (HIV)-associated tuberculosis is high. We conducted a trial with a 2-by-2 factorial design to assess the benefits of early antiretroviral therapy (ART), 6-month isoniazid preventive therapy (IPT), or both among HIV-infected adults with high CD4+ cell counts in Ivory Coast. METHODS: We included participants who had HIV type 1 infection and a CD4+ count of less than 800 cells per cubic millimeter and who met no criteria for starting ART according to World Health Organization (WHO) guidelines. Participants were randomly assigned to one of four treatment groups: deferred ART (ART initiation according to WHO criteria), deferred ART plus IPT, early ART (immediate ART initiation), or early ART plus IPT. The primary end point was a composite of diseases included in the case definition of the acquired immunodeficiency syndrome (AIDS), non-AIDS-defining cancer, non-AIDS-defining invasive bacterial disease, or death from any cause at 30 months. We used Cox proportional models to compare outcomes between the deferred-ART and early-ART strategies and between the IPT and no-IPT strategies. RESULTS: A total of 2056 patients (41% with a baseline CD4+ count of ≥500 cells per cubic millimeter) were followed for 4757 patient-years. A total of 204 primary end-point events were observed (3.8 events per 100 person-years; 95% confidence interval [CI], 3.3 to 4.4), including 68 in patients with a baseline CD4+ count of at least 500 cells per cubic millimeter (3.2 events per 100 person-years; 95% CI, 2.4 to 4.0). Tuberculosis and invasive bacterial diseases accounted for 42% and 27% of primary end-point events, respectively. The risk of death or severe HIV-related illness was lower with early ART than with deferred ART (adjusted hazard ratio, 0.56; 95% CI, 0.41 to 0.76; adjusted hazard ratio among patients with a baseline CD4+ count of ≥500 cells per cubic millimeter, 0.56; 95% CI, 0.33 to 0.94) and lower with IPT than with no IPT (adjusted hazard ratio, 0.65; 95% CI, 0.48 to 0.88; adjusted hazard ratio among patients with a baseline CD4+ count of ≥500 cells per cubic millimeter, 0.61; 95% CI, 0.36 to 1.01). The 30-month probability of grade 3 or 4 adverse events did not differ significantly among the strategies. CONCLUSIONS: In this African country, immediate ART and 6 months of IPT independently led to lower rates of severe illness than did deferred ART and no IPT, both overall and among patients with CD4+ counts of at least 500 cells per cubic millimeter. (Funded by the French National Agency for Research on AIDS and Viral Hepatitis; TEMPRANO ANRS 12136 ClinicalTrials.gov number, NCT00495651.)