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1.
Malar J ; 23(1): 205, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38982475

RESUMEN

BACKGROUND: Drug resistance in Plasmodium falciparum is a major threat to malaria control efforts. Pathogen genomic surveillance could be invaluable for monitoring current and emerging parasite drug resistance. METHODS: Data from two decades (2000-2020) of continuous molecular surveillance of P. falciparum parasites from Senegal were retrospectively examined to assess historical changes in malaria drug resistance mutations. Several known drug resistance markers and their surrounding haplotypes were profiled using a combination of single nucleotide polymorphism (SNP) molecular surveillance and whole genome sequence based population genomics. RESULTS: This dataset was used to track temporal changes in drug resistance markers whose timing correspond to historically significant events such as the withdrawal of chloroquine (CQ) and the introduction of sulfadoxine-pyrimethamine (SP) in 2003. Changes in the mutation frequency at Pfcrt K76T and Pfdhps A437G coinciding with the 2014 introduction of seasonal malaria chemoprevention (SMC) in Senegal were observed. In 2014, the frequency of Pfcrt K76T increased while the frequency of Pfdhps A437G declined. Haplotype-based analyses of Pfcrt K76T showed that this rapid increase was due to a recent selective sweep that started after 2014. DISCUSSION (CONCLUSION): The rapid increase in Pfcrt K76T is troubling and could be a sign of emerging amodiaquine (AQ) resistance in Senegal. Emerging AQ resistance may threaten the future clinical efficacy of artesunate-amodiaquine (ASAQ) and AQ-dependent SMC chemoprevention. These results highlight the potential of molecular surveillance for detecting rapid changes in parasite populations and stress the need to monitor the effectiveness of AQ as a partner drug for artemisinin-based combination therapy (ACT) and for chemoprevention.


Asunto(s)
Antimaláricos , Resistencia a Medicamentos , Mutación , Plasmodium falciparum , Senegal , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/genética , Resistencia a Medicamentos/genética , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Estudios Retrospectivos , Humanos , Malaria Falciparum/parasitología , Malaria Falciparum/epidemiología , Polimorfismo de Nucleótido Simple , Proteínas Protozoarias/genética , Haplotipos , Proteínas de Transporte de Membrana/genética
2.
BMC Res Notes ; 17(1): 68, 2024 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-38461329

RESUMEN

BACKGROUND: Following WHO guidelines, microscopy is the gold standard for malaria diagnosis in endemic countries. The Parasitology-Mycology laboratory (LPM) is the National Reference Laboratory and is currently undergoing ISO 15189 accreditation. In this context, we assessed the performance of the laboratory by confirming the reliability and the accuracy of results obtained in accordance with the requirements of the ISO 15189 standards. This study aimed to verify the method of microscopic diagnosis of malaria at the LPM, in the Aristide Le Dantec hospital (HALD) in Dakar, Senegal. METHODS: This is a validation/verification study conducted from June to August 2020. Twenty (20) microscopic slides of thick/thin blood smear with known parasite densities (PD) selected from the Cheick Anta Diop University malaria slide bank in Dakar were used for this assessment. Six (6) were used to assess microscopists' ability to determine PD and fourteen (14) slides were used for detection (positive vs negative) and identification of parasites. Four (4) LPM-HALD microscopists read and recorded their results on prepared sheets. Data analysis was done with Microsoft Excel 2010 software. RESULTS: A minimum threshold of 50% concordance was used for comparison. Of the twenty (20) slides read, 100% concordance was obtained on eight (8) detection (positive vs negative) slides. Four (4) out of the six (6) parasite density evaluation slides obtained a concordance of less than 50%. Thirteen (13) out of the fourteen (14) identification slides obtained a concordance greater than 50%. Only one (1) identification slide obtained zero agreement from the microscopists. For species identification a concordance greater than 80% was noted and the microscopists obtained scores between 0.20 and 0.4 on a scale of 0 to 1 for parasite density reading. The microscopists obtained 100% precision, sensitivity, specificity and both negative and positive predictive values. CONCLUSION: This work demonstrated that the microscopic method of malaria diagnosis used in the LPM/HALD is in accordance with the requirements of WHO and ISO 15189. Further training of microscopists may be needed to maintain competency.


Asunto(s)
Malaria , Humanos , Senegal , Reproducibilidad de los Resultados , Malaria/diagnóstico , Malaria/parasitología , Laboratorios , Hospitales Universitarios
3.
Nat Commun ; 15(1): 747, 2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38272885

RESUMEN

The worldwide decline in malaria incidence is revealing the extensive burden of non-malarial febrile illness (NMFI), which remains poorly understood and difficult to diagnose. To characterize NMFI in Senegal, we collected venous blood and clinical metadata in a cross-sectional study of febrile patients and healthy controls in a low malaria burden area. Using 16S and untargeted sequencing, we detected viral, bacterial, or eukaryotic pathogens in 23% (38/163) of NMFI cases. Bacteria were the most common, with relapsing fever Borrelia and spotted fever Rickettsia found in 15.5% and 3.8% of cases, respectively. Four viral pathogens were found in a total of 7 febrile cases (3.5%). Sequencing also detected undiagnosed Plasmodium, including one putative P. ovale infection. We developed a logistic regression model that can distinguish Borrelia from NMFIs with similar presentation based on symptoms and vital signs (F1 score: 0.823). These results highlight the challenge and importance of improved diagnostics, especially for Borrelia, to support diagnosis and surveillance.


Asunto(s)
Borrelia , Malaria , Plasmodium , Humanos , Senegal/epidemiología , Estudios Transversales , Malaria/diagnóstico , Malaria/epidemiología , Fiebre/epidemiología , Borrelia/genética
4.
medRxiv ; 2023 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-37662407

RESUMEN

The worldwide decline in malaria incidence is revealing the extensive burden of non-malarial febrile illness (NMFI), which remains poorly understood and difficult to diagnose. To characterize NMFI in Senegal, we collected venous blood and clinical metadata from febrile patients and healthy controls in a low malaria burden area. Using 16S and unbiased sequencing, we detected viral, bacterial, or eukaryotic pathogens in 29% of NMFI cases. Bacteria were the most common, with relapsing fever Borrelia and spotted fever Rickettsia found in 15% and 3.7% of cases, respectively. Four viral pathogens were found in a total of 7 febrile cases (3.5%). Sequencing also detected undiagnosed Plasmodium, including one putative P. ovale infection. We developed a logistic regression model to distinguish Borrelia from NMFIs with similar presentation based on symptoms and vital signs. These results highlight the challenge and importance of improved diagnostics, especially for Borrelia, to support diagnosis and surveillance.

5.
Sci Rep ; 11(1): 10321, 2021 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-33990632

RESUMEN

Dengue virus is a major and rapidly growing public health concern in tropic and subtropic regions across the globe. In late 2018, Senegal experienced its largest dengue virus outbreak to date, covering several regions. However, little is known about the genetic diversity of dengue virus (DENV) in Senegal. Here we report complete viral genomes from 17 previously undetected DENV cases from the city of Thiès. In total we identified 19 cases of DENV in a cohort of 198 individuals with fever collected in October and November 2018. We detected 3 co-circulating serotypes; DENV 3 was the most frequent accounting for 11/17 sequences (65%), 4 (23%) were DENV2 and 2 (12%) were DENV1. Sequences were most similar to recent sequences from West Africa, suggesting ongoing local circulation of viral populations; however, detailed inference is limited by the scarcity of available genomic data. We did not find clear associations with reported clinical signs or symptoms, highlighting the importance of testing for diagnosing febrile diseases. Overall, these findings expand the known range of DENV in Senegal, and underscore the need for better genomic characterization of DENV in West Africa.


Asunto(s)
Virus del Dengue/genética , Dengue/virología , Brotes de Enfermedades/estadística & datos numéricos , Adolescente , Adulto , Anciano , Niño , Preescolar , ADN Viral/aislamiento & purificación , Dengue/sangre , Dengue/diagnóstico , Dengue/epidemiología , Virus del Dengue/aislamiento & purificación , Femenino , Genoma Viral , Humanos , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Filogenia , Senegal/epidemiología , Serogrupo , Adulto Joven
6.
Bull Soc Pathol Exot ; 113(5): 263-267, 2020.
Artículo en Francés | MEDLINE | ID: mdl-33881253

RESUMEN

This study aims to describe the epidemiological, clinical, therapeutic characteristics of patients followed for tuberculosis at the Regional Hospital Center of Tahoua (Niger) as well as their outcomes.We conducted a retrospective and descriptive study from the medical records of patients followed for tuberculosis between January 1, 2017 and December 31, 2019. A total of 465 patients were included in the present study (304 men and 161 women; mean age: 30 years). Patients coming from urban areas represented 51% of the cases. Bacteriologically confirmed pulmonary tuberculosis represented 63% of the cases, 15% of clinically diagnosed pulmonary tuberculosis and 22% of extrapulmonary tuberculosis including Pott's disease. The HIV testing rate was 97.8%. Tuberculosis-HIV association represented 13% of the cases. The therapeutic success was 90.5%. The lethality rate was 5.2% (24/465). Among 24 patients who died, three had tuberculosis-HIV association.


L'objectif de cette étude était de décrire le profil clinique, thérapeutique et évolutif des patients suivis pour tuberculose (TB) au centre hospitalier régional de Tahoua (Niger). Nous avons mené une étude rétrospective, descriptive à partir des dossiers des patients suivis pour TB entre le 1er janvier 2017 et le 31 décembre 2019. Au total, 465 patients ont été inclus dans la présente étude (304 hommes et 161 femmes, âge moyen : 30 ans). Les patients provenant du milieu urbain représentaient 51 % des cas. La TB pulmonaire confirmée bactériologiquement représentait 63 % des cas, la TB pulmonaire cliniquement diagnostiquée 15 %, la TB extrapulmonaire, notamment le mal de Pott, 22 %. L'association TB­VIH représentait 13 % des cas. Le succès thérapeutique était de 90,5 %. Le taux de létalité était de 5,2 % (24/465). Parmi les 24 patients décédés, trois présentaient l'association TB­VIH.


Asunto(s)
Tuberculosis Pulmonar , Tuberculosis de la Columna Vertebral , Adulto , Femenino , Hospitales , Humanos , Masculino , Niger/epidemiología , Estudios Retrospectivos
7.
Data Brief ; 23: 103699, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30828596

RESUMEN

The dataset described in this data article represents four agricultural zones in West-Africa that are located in three countries: Benin, Mali and Sierra Leone. The dataset was created through a research collaboration between the Africa Rice Center (AfricaRice), Sierra Leone Agricultural Research Institute (SLARI) and the Institute for Rural Economy (IER). The dataset was compiled to investigate the potential for rice production in inland valleys of the three countries. The results of the investigation were published in Dossou-Yovo et al. (2017) and Djagba et al. (2018). The dataset describes the biophysical and socioeconomic conditions of 499 inland valleys in the four agricultural zones. In each inland valley data were collected through a focus group interview with a minimum of three farmers. In 499 interviews a total of 7496 farmers participated. The location of each inland valley was determined with handheld GPS devices. The geographic locations were used to extract additional parameters from digital maps on soils, elevation, population density, rainfall, flow accumulation, and distances to roads, market places, rice mills, chemical input stores, and settlements. The dataset contains 65 parameters in four themes (location, biophysical characteristics, socioeconomic characteristics, and inland valley land development and use). The GPS coordinates indicate the location of an inland valley, but they do not lead to the location of individual fields of farmers that were interviewed. The dataset is publicly shared as Supplementary data to this data article.

8.
Data Brief ; 19: 2008-2014, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30229074

RESUMEN

The data described in this article are related to drought occurrence in inland valleys and farmers adaptation strategies. The data were collected in 300 inland valleys distributed in 14 regions of West Africa. The data were collected in two phases. In the first phase, 300 inland valleys were identified in 14 regions and their locations were determined with handheld GPS devices. Questionnaires and informal interviews were administered to inland valleys users to collect data on physical and socio-economic characteristics, hydrology, farmers experience with drought affecting rice production in inland valleys and adaptation strategies. In the second phase, the locations of the inland valleys were imported in a GIS environment and were used to extract additional parameters on soil characteristics and water demand from the Shuttle Radar Topography Mission (SRTM), Africa Soil Information Service (africasoils.net) and POWER database (http://power.larc.nasa.gov). In total, the dataset contains 41 variables divided into seven themes: farmers' experience with drought, adaptive management of rice farmers to drought, physical characteristics, hydrology, management practices, socio-economic characteristics and weather data of inland valleys.

9.
Med Sante Trop ; 27(3): 264-269, 2017 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-28947401

RESUMEN

To report etiological and prognostic characteristics of acute peritonitis in children. This retrospective study reviewed the records for a 30-month period (January 2013-June 2015) at Zinder National Hospital (Niger) of all children between the ages of 0-15 years who underwent surgery for non-traumatic acute peritonitis. Statistical tests were performed, with significance defined by a P-value < 5 %. Acute peritonitis accounted for 62.12 % (226/358) of all emergency gastrointestinal surgery in children. Their median age was 10 years (range: 0-15 years), with almost two-thirds of them male (n=148). Ileal perforation, presumably due to typhoid fever, was the main cause (n=153), with acute appendicular peritonitis in second place, accounting for 25.22 % (n=57) of cases. Gastrointestinal ostomy was performed in 101 patients (44.7 %) and an appendectomy in 56 (24.8 %). The average length of stay was 10.9±3.6 days. Postoperative complications, defined by the Clavien-Dindo classification, occurred in 46.5 % of these procedures (n=105). Surgical site infections were recorded in 66 cases. Overall mortality was 13.7 % (n=31) and was statistically associated with an American Society of Anesthesiologists (ASA) score of IV (OR = 3,32 : 1,07-10,27 ; P = 0,037) and Mannheim Peritonitis Index (MPI) ≥ 26 (OR = 44,68 : 10,17 - 196,32 ; P = 0,000), time to admission (OR = 4,626 : 1,39 - 15,34, P = 0,012), and time to surgery in hours (OR = 4,59 : 1,60 - 13,18 ; P = 0,0046). In Niger, perforation apparently due to typhoid is the main cause of peritonitis in children. Mortality is associated with an ASA score of IV, Mannheim Peritonitis Index ≥ 26, time to admission, and time to surgery.


Asunto(s)
Peritonitis/etiología , Enfermedad Aguda , Adolescente , Niño , Preescolar , Femenino , Hospitales , Humanos , Lactante , Masculino , Niger , Peritonitis/cirugía , Pronóstico , Estudios Retrospectivos
10.
PLoS One ; 12(1): e0169547, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28103262

RESUMEN

BACKGROUND: To mitigate the burden of pneumococcal infections in Niger, a 13-valent pneumococcal vaccine, PCV13, was introduced for routine child vaccination in July 2014. In order to provide pre-vaccine baseline data and allow appreciation of changes on carriage due to vaccination, we analyzed retrospectively pneumococcal isolates obtained from healthy, 0 to 2 year old children prior to the vaccine introduction. METHODS: From June 5, 2007, to May 26, 2008, 1200 nasopharyngeal swabs were collected from healthy 0 to 2 year old children and analyzed by standard microbiological methods. Serotyping was done by SM-PCR and the data were analyzed with R version 2.15.0 (2012-03-30). RESULTS: Streptococcus pneumoniae was detected in 654/1200 children (54.5%) among whom 339 (51.8%) were males. The ages of the study subjects varied from few days to 26 months (mean = 7.1, median = 6, 95% CI [6.8-7.4]). Out of 654 frozen isolates, 377 (54.8%) were able to be re-grown and analyzed. In total, 32 different serogroups/serotypes were detected of which, the most prevalent were 6/(6A/6B/6C/6D) (15.6%), 23F (10.6%), 19F (9.3%), 14 (9%), 19A (5.6%), 23B (4.0%), 25F/38 (3.7%), 18/(18A/18B/18C/18F) (2.9%) and PCR non-typeable (16.4%). Eleven serogroups/serotypes accounting for 57.3% (216/377) were of PCV13 types. Of the 211/377 (56%) isolates tested for drug sensitivity, 23/211 (10.9%), 24/211 (11.4%), 9/211(4.3%) and 148/210 (70.5%) were respectively resistance to oxacillin, chloramphenicol, erythromycin and tetracycline. Thirteen of the oxacillin resistant isolates were additionally multidrug-resistant. No resistance was however detected to gentamycin500µg and to fluoroquinolones (ø Norfloxacin5µg <7mm). Age > 3 months and presence in family of more than one sibling aged < 6 years were significant risk factors for carriage. CONCLUSION: A global rate of 54.5% pneumococcal carriage was detected in this study. The introduced PCV13 vaccine should cover 57.3% (216/377) of circulating serogroups/serotypes, among which were those resistant to antibiotics. Age > 3 months and presence in family of children aged < 6 years were significant factors for pneumococcal carriage. The present data should help understanding post vaccine introduction changes in pneumococcal carriage and infections for better action.


Asunto(s)
Portador Sano/microbiología , Infecciones Neumocócicas/prevención & control , Streptococcus pneumoniae/clasificación , Streptococcus pneumoniae/efectos de los fármacos , Portador Sano/epidemiología , Portador Sano/prevención & control , Preescolar , Farmacorresistencia Bacteriana , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Nasofaringe/microbiología , Niger/epidemiología , Infecciones Neumocócicas/epidemiología , Infecciones Neumocócicas/microbiología , Vacunas Neumococicas/farmacología , Estudios Retrospectivos , Serogrupo , Streptococcus pneumoniae/aislamiento & purificación
11.
Chem Commun (Camb) ; 52(82): 12214-12217, 2016 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-27711381

RESUMEN

In this report, we present a new path to the control of quantum dot surface chemistry that can lead to a better understanding of nanoscale interfaces and the development of improved photocatalysts. Control of the synthetic methodology leads to QDs that are concomitantly ligated by crystal-bound organics at the surface anion sites and small X-type ligands on the surface cation sites.

13.
Microb Ecol ; 68(2): 329-38, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24595907

RESUMEN

Pterocarpus officinalis Jacq. is a legume tree native to the Caribbean islands and South America growing as a dominant species in swamp forests. To analyze (i) the genetic diversity and (ii) the symbiotic properties of its associated nitrogen-fixing soil bacteria, root nodules were collected from P. officinalis distributed in 16 forest sites of the Caribbean islands and French Guiana. The sequencing of the 16S-23S ribosomal RNA intergenic spacer region (ITS) showed that all bacteria belonged to the Bradyrhizobium genus. Bacteria isolated from insular zones showed very close sequence homologies with Bradyrhizobium genospecies V belonging to the Bradyrhizobium japonicum super-clade. By contrast, bacteria isolated from continental region displayed a larger genetic diversity and belonged to B. elkanii super-clade. Two strains from Puerto Rico and one from French Guiana were not related to any known sequence and could be defined as a new genospecies. Inoculation experiments did not show any host specificity of the Bradyrhizobium strains tested in terms of infectivity. However, homologous Bradyrhizobium sp. strain-P. officinalis provenance associations were more efficient in terms of nodule production, N acquisition, and growth than heterologous ones. The dominant status of P. officinalis in the islands may explain the lower bacterial diversity compared to that found in the continent where P. officinalis is associated with other leguminous tree species. The specificity in efficiency found between Bradyrhizobium strains and host tree provenances could be due to a coevolution process between both partners and needs to be taken in consideration in the framework of rehabilitation plantation programs.


Asunto(s)
Bradyrhizobium/clasificación , Variación Genética , Filogenia , Pterocarpus/microbiología , Bradyrhizobium/genética , Bradyrhizobium/aislamiento & purificación , ADN Bacteriano/genética , ADN Espaciador Ribosómico/genética , Bosques , Guyana Francesa , ARN Ribosómico 16S/genética , ARN Ribosómico 23S/genética , Nódulos de las Raíces de las Plantas/microbiología , Análisis de Secuencia de ADN , Simbiosis , Indias Occidentales
15.
Environ Manage ; 50(5): 929-41, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22941197

RESUMEN

Semi-structured focus group discussions were employed to capture rural Senegalese attitudes and perceptions of their behavior to changes in the climate and their land use and livelihood strategies. Seven focus groups stratified by gender, ethnicity (Wolof and Peulh) and dominant production system (cultivators and pastoralists) in five villages in semi-arid northern Senegal revealed seven main themes. Rural livelihoods remain predominantly based on rainfall dependant practices, and although cultivators and pastoralists had a clear appreciation of changes in natural resources compared to a perceived more favorable past, few adaptive coping strategies beyond established ones were advocated. The seven themes are discussed in detail and their implications for rural livelihoods under future long term climate predictions discussed with the implications of this study for the development of scenarios of future land cover land use.


Asunto(s)
Actitud , Clima , Percepción , Femenino , Humanos , Masculino , Población Rural , Senegal
16.
Mycorrhiza ; 22(3): 175-87, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21660609

RESUMEN

Fifty years of overexploitation have disturbed most forests within Sahelian areas. Exotic fast growing trees (i.e., Australian Acacia species) have subsequently been introduced for soil improvement and fuelwood production purposes. Additionally, rhizobial or mycorrhizal symbioses have sometimes been favored by means of controlled inoculations to increase the performance of these exotic trees in such arid and semiarid zones. Large-scale anthropogenic introduction of exotic plants could also threaten the native biodiversity and ecosystem resilience. We carried out an experimental reforestation in Burkina Faso in order to study the effects of Acacia holosericea mycorrhizal inoculation on the soil nutrient content, microbial soil functionalities and mycorrhizal soil potential. Treatments consisted of uninoculated A. holosericea, preplanting fertilizer application and arbuscular mycorrhizal inoculation with Glomus intraradices. Our results showed that (i) arbuscular mycorrhizal (AM) inoculation and prefertilizer application significantly improved A. holosericea growth after 4 years of plantation and (ii) the introduction of A. holosericea trees significantly modified soil microbial functions. The results clearly showed that the use of exotic tree legume species should be directly responsible for important changes in soil microbiota with great disturbances in essential functions driven by microbial communities (e.g., catabolic diversity and C cycling, phosphatase activity and P availability). They also highlighted the importance of AM symbiosis in the functioning of soils and forest plantation performances. The AM effect on soil functions was significantly correlated with the enhanced mycorrhizal soil potential recorded in the AM inoculation treatment.


Asunto(s)
Acacia/microbiología , Ecosistema , Glomeromycota/fisiología , Micorrizas/fisiología , Microbiología del Suelo , Árboles/microbiología , Acacia/crecimiento & desarrollo , África del Norte , Fertilizantes/análisis , Raíces de Plantas/microbiología , Suelo/análisis , Árboles/crecimiento & desarrollo
17.
Mycorrhiza ; 22(1): 1-29, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21989710

RESUMEN

The diversity, ecology and function of ectomycorrhizal (EM) fungi and ectomycorrhizas (ECMs) on tropical African tree species are reviewed here. While ECMs are the most frequent mycorrhizal type in temperate and boreal forests, they concern an economically and ecologically important minority of plants in African tropical forests. In these African tropical forests, ECMs are found mainly on caesalpionioid legumes, Sarcolaenaceae, Dipterocarpaceae, Asterpeiaceae, Phyllantaceae, Sapotaceae, Papilionoideae, Gnetaceae and Proteaceae, and distributed in open, gallery and rainforests of the Guineo-Congolian basin, Zambezian Miombo woodlands of East and South-Central Africa and Sudanian savannah woodlands of the sub-sahara. Overall, EM status was confirmed in 93 (26%) among 354 tree species belonging to EM genera. In addition, 195 fungal taxa were identified using morphological descriptions and sequencing of the ML5/ML6 fragment of sporocarps and ECMs from West Africa. Analyses of the belowground EM fungal communities mostly based on fungal internal transcribed spacer sequences of ECMs from Continental Africa, Madagascar and the Seychelles also revealed more than 350 putative species of EM fungi belonging mainly to 18 phylogenetic lineages. As in temperate forests, the /russula-lactarius and /tomentella-thelephora lineages dominated EM fungal flora in tropical Africa. A low level of host preference and dominance of multi-host fungal taxa on different African adult tree species and their seedlings were revealed, suggesting a potential for the formation of common ectomycorrhizal networks. Moreover, the EM inoculum potential in terms of types and density of propagules (spores, sclerotia, EM root fragments and fragments of mycelia strands) in the soil allowed opportunistic root colonisation as well as long-term survival in the soil during the dry season. These are important characteristics when choosing an EM fungus for field application. In this respect, Thelephoroid fungal sp. XM002, an efficient and competitive broad host range EM fungus, possessed these characteristics and appeared to be a good candidate for artificial inoculation of Caesalps and Phyllanthaceae seedlings in nurseries. However, further efforts should be made to assess the genetic and functional diversity of African EM fungi as well as the EM status of unstudied plant species and to strengthen the use of efficient and competitive EM fungi to improve production of ecologically and economically important African multipurpose trees in plantations.


Asunto(s)
Variación Genética/genética , Especificidad del Huésped/fisiología , Micorrizas/fisiología , Simbiosis/fisiología , Árboles/microbiología , África , Basidiomycota/genética , Basidiomycota/fisiología , Ecología , Fabaceae/microbiología , Fabaceae/fisiología , Hongos/genética , Hongos/fisiología , Micorrizas/genética , Raíces de Plantas/microbiología , Raíces de Plantas/fisiología , Plantones/microbiología , Plantones/fisiología , Semillas/microbiología , Semillas/fisiología , Árboles/fisiología , Clima Tropical
18.
Br J Nutr ; 107(12): 1860-70, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22017887

RESUMEN

Food insecurity is affecting an increasing number of urban poor in the developing world. Yet seasonal characteristics of food intakes have rarely been studied in West African cities. The objective of the present study was to assess the seasonality of the dietary dimension of household food security in Ouagadougou (Burkina Faso). In 2007, two sets of data were collected during the lean and post-harvest seasons, respectively, on a representative sample of 1056 households. At each season, two non-consecutive 24 h recalls were performed at the household level. Food prices were also recorded. Household food security was assessed by the household's mean adequacy ratio (MAR) for energy and eleven micronutrients. Changes in the MAR according to the season were analysed by mixed multivariate linear regression. Results showed that intakes of energy and of ten micronutrients were significantly lower during the lean season than during the post-harvest season, leading to a lower MAR in the lean season (49·61 v. 53·57, P < 0·0001). This was related to less frequent consumption and consumption of smaller amounts of vegetables and of foods prepared at home. Food security relied heavily on food expenses (P < 0·0001) and on the price of meat/fish (P = 0·026). Households with economically dependent adults (P = 0·021) and larger households (P < 0·0001) were the most vulnerable, whereas education (P = 0·030), social network (P = 0·054) and urban origin other than Ouagadougou (P = 0·040) played a positive role in food security. To achieve food security in Ouagadougou, access to micronutrient-dense foods needs to be ensured in all seasons.


Asunto(s)
Dieta , Ingestión de Energía , Composición Familiar , Abastecimiento de Alimentos , Micronutrientes/administración & dosificación , Pobreza , Estaciones del Año , Adulto , Burkina Faso , Niño , Ciudades , Comercio , Países en Desarrollo , Dieta/economía , Escolaridad , Conducta Alimentaria , Manipulación de Alimentos/economía , Abastecimiento de Alimentos/economía , Humanos , Modelos Lineales , Carne/economía , Micronutrientes/economía , Análisis Multivariante , Apoyo Social , Población Urbana
19.
Mycorrhiza ; 19(8): 571-584, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19705166

RESUMEN

A combination of morphotypes, polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) analyses and internal transcribed spacer (ITS) sequencing was used to investigate Scleroderma species that were collected from woodlands in Burkina Faso. We harvested 52 specimens from 20 sites during rainy seasons between 1997 and 2000. According to their morphological features, these specimens were initially characterised, and we then identified six species of Scleroderma. Two of the species were clearly determined as Scleroderma dictyosporum Pat. and S. verrucosum Pers. The four remaining species were characteristically described as (1) displaying big spores with spines up to 2 microm (Scleroderma sp1), (2) producing spores without ornamentation (Scleroderma sp2), (3) spores with very small spines (Scleroderma sp3) and (4) with yellow sporocarps and sub-spherical spores (Scleroderma sp4). The specimens were then analysed using PCR/RFLP of the intergenic regions of rDNA, ITS and IGS1 and ITS sequencing. The restriction fragments obtained with two endonucleases, HinfI and MboI on ITS and IGS1 regions, showed that some isolates of S. dictyosporum had the same patterns as isolates and basidiocarps of Scleroderma sp4 (IR265, IR408, SP4-2903). Isolates of Scleroderma sp3 (IR252) had common restriction fragments as isolates of S. verrucosum (IR500, IR600). Intraspecific differences were observed in the two previously determined species, as well as in Scleroderma sp2. The ITS sequencing and phylogenetic analyses showed that the ribotypes identified by PCR/RFLP within these species might be phylogenetic species. Combining these molecular results allowed regrouping the six morphological species in three sets of cryptic species: a first set with two species including S. dictyosporum Pat., a second set with four species, including both S. verrucosum Pers. and Scleroderma sp1 and a third set with two species, including Scleroderma sp2. These investigations and the combined morphological and molecular analyses used to sort out species paved the way for identifying larger populations of Scleroderma species in Burkina Faso and other tropical zones.


Asunto(s)
Basidiomycota/clasificación , Basidiomycota/aislamiento & purificación , Magnoliopsida/microbiología , Basidiomycota/citología , Basidiomycota/genética , Burkina Faso , Análisis por Conglomerados , Dermatoglifia del ADN , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Datos de Secuencia Molecular , Filogenia , Polimorfismo de Longitud del Fragmento de Restricción , Análisis de Secuencia de ADN , Esporas Fúngicas/citología , Árboles
20.
Malar J ; 7: 16, 2008 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-18205945

RESUMEN

BACKGROUND: Artesunate plus amodiaquine is a coblistered ACT, given as a single daily intake. It has been suggested that, in view of the number of tablets to be taken (particularly in adults), it may be possible to improve compliance by allowing patients to divide the daily dose. The objectives of this randomized, comparative, open-label, multicentre study, conducted in Senegal and in Cameroon in 2005, was to demonstrate the non-inferiority and to compare the safety of artesunate plus amodiaquine, as a single daily intake versus two daily intakes. METHODS: A three-day treatment period and 14-day follow-up period was performed in any subject weighting more than 10 kg, presenting with a malaria paroxysm confirmed by parasitaemia > or = 1,000/microl, after informed consent. Patients were randomly allocated into one of the two regimens, with dosage according to bodyweight range. All products were administered by an authorized person, blinded to both the investigating physician and the biologist. The primary endpoint was an adequate response to treatment on D14 (WHO definition). The two-sided 90% confidence interval of the difference was calculated on intent to treat (ITT) population; the acceptance limit for non-inferiority was 3%. The safety was evaluated by incidence of adverse events. RESULTS: Three-hundred and sixteen patients were included in the study. The two patient groups were strictly comparable on D0. The adequate responses to treatment were similar for the two treatment regimens on D14, PCR-corrected (99,4% in the one-daily intake group versus 99,3% in the comparative group). The statistical analyses demonstrated the non-inferiority of administering artesunate/amodiaquine as two intakes. The drug was well tolerated. The main adverse events were gastrointestinal disorders (2.5%) and pruritus (2.5%); safety profiles were similar in the two groups. CONCLUSION: This pilot study confirms the efficacy and good tolerability of artesunate plus amodiaquine, administrated either in one or in two daily intakes.


Asunto(s)
Amodiaquina/administración & dosificación , Amodiaquina/efectos adversos , Antimaláricos/administración & dosificación , Antimaláricos/efectos adversos , Artemisininas/administración & dosificación , Artemisininas/efectos adversos , Malaria Falciparum/tratamiento farmacológico , Sesquiterpenos/administración & dosificación , Sesquiterpenos/efectos adversos , Adolescente , Adulto , Animales , Artesunato , Camerún , Niño , Preescolar , Femenino , Enfermedades Gastrointestinales/fisiopatología , Humanos , Masculino , Parasitemia , Plasmodium falciparum/genética , Plasmodium falciparum/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Prurito , Senegal
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