Study of the Effect of Pseudomonas Putida and Funneliformis Mosseae on the Growth and Productivity of Tomato (Solanum Lycopersicum L.) in Senegal

In Senegal, the Niayes zone plays an important role in the economy of the country. It is the main horticultural production area. Among the crops cultivated, tomato (Solanum lycopersicum L.) is the second place of horticultural crops. However, this crop is confronted with biotic and abiotic constraints leading to lower yields. Thus, the objective of this study is to evaluate the impact of beneficial microorganisms such as rhizobacteria from the group of fluorescent Pseudomonas (Pseudomonas putida) and arbuscular mycorrhizal fungi (Funeliformis mosseae) on the productivity of tomatoes. Soil samples were taken from the rhizosphere of tomato plants. The bacterial strains were isolated by the method of suspensions dilutions, and then seeded on King B medium. Their identification was carried out by using the MALDITOF mass spectrometer. In order to evaluate the effect of these microorganisms on productivity, an experiment was conducted in the field for three months. An experimental device with three randomize blocks was adopted with four block treatments: T (control), PS1 (Pseudomonas putida), Fm (Funneliformis mosseae) and PS1 + Fm. The results obtained showed that the inoculation of tomato plants with PS1 or in combination with Fm induced the best yields with values exceeding respectively 5 t / ha and 1.5 t / ha compared with non-inoculated plants. The yield reductions observed in the case of co-inoculation between Fm and PS1 compared with PS1 treatment alone would suggest an antagonistic effect. These strains of Pseudomonas putida constitute an alternative for the increase of tomato productivity in the Niayes zone

Evaluation of the pulse wave velocity in African rheumatoid arthritis subjects

Background: Rheumatoid arthritis is a systemic disease with often fatal vascular events. In addition to traditional cardiovascular risk factors, disease-specific elements contribute to this cardiovascular mortality. The aim of this study was to assess arterial stiffness in rheumatoid arthritis and to determine the factors involved.Methods: We have recruited the black African patients followed in rheumatology and had rheumatoid arthritis diagnosis. Only patients between 18 and 60 years and meeting the American College of Rheumatology criteria were included. All controls were healthy. We evaluated the propagation velocity of the pulse wave finger-toe (PWVft) measured by the pOpmètre®.Results: Present study shows that the PWVft was significantly elevated in over half of patients (55.10%). Besides, the mean patients PWVft was significantly higher than that of the control (respectively 9.40±0.51 and 7.22±0.33 p=0.001). In the patients, no factor was significantly involved in the arterial stiffness, but cons in the control group, the PWVft was significantly correlated with age (p=0.023 and r=0.55).Conclusions: Rheumatoid arthritis patients had higher PWVft compared to controls. Due to the importance of its cardiovascular morbidity and mortality, arthritis requires a regular monitoring element as arterial stiffness, which is currently a major vascular parameter monitoring

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Permanences et mutations dans les terroirs rizicoles de Basse-Casamance (Sénégal)

International audienceWest Africa undergoes, since more than about forty years, a degradation of the agricultural landscapes. The strong climatic variability of these last decades is one of determining factors of these transformations. It is translated by a decrease of the precipitation and an important case of the periods of rainfall deficit repercussions of which are obvious on the agrarian systems. The rice soils of Low Casamance, a beautiful example of the «agrarian civilizations» of western Africa, translate the current dynamics in the "Rivers of the South". These spaces, which concentrate numerous human activities, present strong natural and socioeconomic constraints, which have consequences on the rice systems. The analysis of the rice soils of Low Casamance, by an approach of the landscapes combining geospatial data and field works, shows dynamics contrasted between the rice activity and its environment biophysics and socioeconomic.L'Afrique de l'Ouest subit, depuis plus d'une quarantaine d'années, une dégradation des paysages agricoles. La forte variabilité climatique de ces dernières décennies est un des facteurs déterminants de ces transformations. Elle se traduit par une diminution des précipitations et une importante occurrence des périodes de déficit pluviométrique dont les répercussions sont manifestes sur les systèmes agraires. Les terroirs rizicoles de Basse-Casamance, emblématique des "civilisations agraires" d'Afrique de l'Ouest, traduisent les dynamiques en cours dans les "Rivières du Sud". Ces espaces, qui concentrent de nombreuses activités humaines, présentent de fortes contraintes naturelles et socioéconomiques qui ont des conséquences sur les systèmes rizicoles. L'analyse des terroirs rizicoles de Basse-Casamance, par une approche des paysages combinant des données géospatiales et des travaux de terrain, montre des dynamiques contrastées entre l'activité rizicole et son environnement biophysique et socio-économique. L'analyse des photographies aériennes et des images Google Earth, en particulier, fait apparaître un recul des terroirs rizicoles induit par la forte variabilité climatique, la salinisation et l'acidification des eaux et des terres, et par l'insuffisante main d'oeuvre liée à l'exode des jeunes qui se traduit par le manque d'entretien des digues de protection des parcelles rizicoles. Elle révèle ainsi l'existence de fortes interactions entre activités agricoles, écosystèmes exploités et environnement socio-économique

Evaluation of agreement between hemoglobin A1c, fasting glucose, and fructosamine in Senegalese individuals with and without sickle-cell trait

International audienc

Evaluation of the pulse wave velocity in African rheumatoid arthritis subjects

Background: Rheumatoid arthritis is a systemic disease with often fatal vascular events. In addition to traditional cardiovascular risk factors, disease-specific elements contribute to this cardiovascular mortality. The aim of this study was to assess arterial stiffness in rheumatoid arthritis and to determine the factors involved.Methods: We have recruited the black African patients followed in rheumatology and had rheumatoid arthritis diagnosis. Only patients between 18 and 60 years and meeting the American College of Rheumatology criteria were included. All controls were healthy. We evaluated the propagation velocity of the pulse wave finger-toe (PWVft) measured by the pOpmètre®.Results: Present study shows that the PWVft was significantly elevated in over half of patients (55.10%). Besides, the mean patients PWVft was significantly higher than that of the control (respectively 9.40±0.51 and 7.22±0.33 p=0.001). In the patients, no factor was significantly involved in the arterial stiffness, but cons in the control group, the PWVft was significantly correlated with age (p=0.023 and r=0.55).Conclusions: Rheumatoid arthritis patients had higher PWVft compared to controls. Due to the importance of its cardiovascular morbidity and mortality, arthritis requires a regular monitoring element as arterial stiffness, which is currently a major vascular parameter monitoring

Increased Prevalence of Type 2 Diabetes–Related Complications in Combined Type 2 Diabetes and Sickle-Cell Trait

International audienceOBJECTIVE: The prevalence of type 2 diabetes (T2D) is rapidly increasing in sub-Saharan Africa, where sickle cell trait (SCT) is also frequent. Although SCT is generally considered a benign condition, evidence suggests that SCT could exaggerate vascular dysfunction in T2D. However, it remains unclear whether SCT could increase the risk of the development of T2D complications. Therefore, this study was conducted to determine whether T2D complications were more prevalent among Senegalese individuals with SCT and T2D than among those with T2D only. RESEARCH DESIGN AND METHODS: Rates of hypertension, retinopathy, peripheral neuropathy, peripheral artery disease, and impaired renal function as well as arterial stiffness, blood rheology, and concentrations of plasma advanced glycation end products (AGEs) and cytokines were compared between groups of Senegalese individuals with combined SCT and T2D (T2D-SCT) (n = 60), T2D (n = 52), SCT (n = 53), and neither T2D nor SCT (control) (n = 56). Human aortic endothelial cell (HAEC) expression of inflammatory and adhesion factors was measured after treatment with tumor necrosis factor-α and subjects' plasma. Effects of AGE inhibition or tiron on HAEC expression of E-selectin were measured. RESULTS: Retinopathy, hypertension, and reduced renal function were more prevalent, and arterial stiffness, blood viscosity at high shear rates, and thixotropic index were higher, in the SCT group compared with the other groups. Multivariable analysis showed that plasma AGE concentration was significantly associated with arterial stiffness. E-selectin expression was elevated in HAECs treated with T2D-SCT plasma compared with the other groups, but AGE inhibition reversed this. CONCLUSIONS: SCT could potentially augment the risk of the development of T2D-related complications, including retinopathy, nephropathy, and hypertension