RÉSUMÉ Objectif : Dans le but d’évaluer l’influence de la fiente de poules sur le rendement et la composition biochimique des tubercules de deux variétés de pomme de terre (Nicola et Mandola) soumises au stress hydrique, un essai a été conduit en plein champ et sous serre sur sol ferrallitique sans taches à Pita en République de Guinée. Méthodes et résultats : Un dispositif split-plot (2x4x3) a été utilisé en plein champ, soit deux variétés (V1 et V2) sur les grandes parcelles, et quatre doses (D0, D1, D2 et D3) de fiente de poules dans les petites parcelles, le tout en trois répétitions. Sous serre, des pots en plastic ont été disposés en split split-plot (2x3x5x3) et les deux variétés de pomme de terre testé à trois niveaux de stress (Nul, Modéré et Sévère) suivant la capacité de rétention maximale avec 5 proportions de fiente de poules en trois répétitions. Les résultats indiquent que la fiente d’une manière générale a augmenté le rendement des deux variétés. Conclusion et application des résultats : Au champ, l’application des doses de fientes a fait varier la composition biochimique des deux variétés. Sous serre, les niveaux de stress hydrique et les proportions fiente : sol ont considérablement réduit les valeurs des compositions biochimiques évaluées. Les teneurs en matière sèche et en lipides des tubercules ont diminué par rapport aux témoins. On constate que, du point de vue des tubercules, que ce soit en plein champ ou sous serre, la variété Nicola a donné plus de rendement et a été plus résistante au stress hydrique que la variété Mandola pour toutes les doses de fiente appliquée. En conclusion, l’engrais à base de fiente de poule contribue à améliorer les conditions de la culture en cas de stress modéré et même sévère. Mots-clés : Variétés de pomme de terre (Solanum tuberosum), Fiente de poules, Composition biochimique, Serre, Stress hydrique, Guinée. 20538 Bah et al., J. Appl. Biosci. Vol: 194, 2024 Influence d’un engrais à base de fiente de poule sur le rendement et la composition biochimique de la pomme de terre (S. tuberosum) soumises au stress hydrique sur sol ferrallitique Influence of chickens manure on yield and biochemical composition of potato (Solanum tuberosum) in response to water stress under Ferralsols ABSTRACT Objectives : This research aims to evaluate the effects of chicken manure on the yield and biochemical composition of two potato varieties (Nicola and Mandola) subjected to water stress. An experiment was conducted in both open field and greenhouse under ferralitic soil without stains in Pita, Guinea. The results showed that both potatoes yields increased with the application of chickens manure. Methodology and Results : A split-plot design (3x2x4) was implemented in the open field by considering two varieties (V1 and V2) as biggest plots, four doses (D0, D1, D2 and D3 in t/ha) of chicken manure as smallest plots with three replicates. Under the greenhouse, plastic pots were arranged into a split-split plot design of (3x2x3x5) and the two varieties were tested at three levels of water stress (control, moderate and several) following to the maximum retention capacity with 5 ratios of chickens manure and soil with three replicates. Results from the open field revealed that the dry matter content and the lipid levels varied from one variant to another. Conclusions and application of findings: In addition, results from the greenhouse indicated that water stress levels, chickens manure: soil ratios significantly reduced the values of the various biochemical compositions evaluated. Finally, either in the open field or greenhouse, the biochemical composition of tubers revealed that the Nicola variety was more resistant to water stress than the Mandola one for both applied doses of chickens manure. Key words: Chickens manure - Biochemical composition - Greenhouse - Water stress - Potato varieties - Guinea.

Objectif : Une étude sur la combinaison des méthodes de levée de la dormance du petit Kola (Garcinia kola, Heckel) à l’Institut Supérieur Agronomique et Vétérinaire de Faranah a été réalisée. L’objectif de cette étude était d’évaluer l’effet du mode de traitement et du type de substrats sur la levée de la dormance du petit cola afin de réduire le temps de germination. Méthodologie et résultats : L’étude a été réalisée avec un dispositif de bloc de Fisher comportant neuf (9) traitements d’étude répétés trois fois chacun. Les résultats ont montré la germination de toutes graines semées (100%) avec une levée de dormance constatée au 63 jours après le semis au niveau du prétraitement avec l’eau tiède pour une durée de 48 heures et une température de 24°C combiné avec le terreau. Conclusion et applications pratiques/recommandations : Les prétraitements avec de l’eau tiède et de l’eau chaude ont levé la dormance du petit cola qui est de neuf (9) mois en milieu rural. Des recherches sont en cours afin de trouver un temps record pour la germination et la résistance au stress hydrique du petit cola.

The Zika virus (ZIKV) is a widespread mosquito-borne pathogen. Phylogenetically, two lineages of ZIKV are distinguished: African and Asian-American. The latter became the cause of the 2015-2016 pandemic, with severe consequences for newborns. In West African countries, the African lineage was found, but there is evidence of the emergence of the Asian-American lineage in Cape Verde and Angola. This highlights the need to not only monitor ZIKV but also sequence the isolates. In this article, we present a case report of Zika fever in a pregnant woman from Guinea identified in 2018. Viral RNA was detected through qRT-PCR in a serum sample. In addition, the seroconversion of anti-Zika IgM and IgG antibodies was detected in repeated blood samples. Subsequently, the virus was isolated from the C6/36 cell line. The detected ZIKV belonged to the African lineage, the Nigerian sublineage. The strains with the closest sequences were isolated from mosquitoes in Senegal in 2011 and 2015. In addition, we conducted the serological screening of 116 blood samples collected from patients presenting to the hospital of Faranah with fevers during the period 2018-2021. As a result, it was found that IgM-positive patients were identified each year and that the seroprevalence varied between 5.6% and 17.1%.

Locusta migratoria is a serious agricultural pest in China. Beauveria bassiana is one of the most important pathogens of grasshoppers and locusts. The effects of ultraviolet light were evaluated on the B. bassiana strain BbZJ1. The results showed that 253.7 and 360nm wavelength UV (Ultra Violet) did not affect the germination of B. bassiana after its recovery from UV treatments. Nevertheless, the virulence of B. bassiana BbZJ1 after its recovery from radiation of UV (253.7nm) increased. The mortality rates were 85.00% for the BbZJ1 control, was 96.67% for BbZJ1 recovered from radiation of UV (253.7nm) for 60min. After treatment with 253.7nm UV radiation for 60min, the expression levels of stress-resistant genes BbAlg9 and Bbadh2 in BbZJ1 strain were 2.68 and 2.29 times higher than those in the control group, respectively. Meanwhile, the B. bassiana prepared in 5% groundnut oil showed highest tolerance levels to the ultraviolet radiation. The 5% groundnut oil was the most suitable potential UV-protectant for B. bassiana in terms of cost and availability.

The stability of symbiotic flora is an important indicator of the health of an organism. Symbiotic bacteria have been proven to be closely involved in the immune process of organisms. The pathogenicity of Beauveria bassiana was studied in relation to symbiotic bacteria on the surface and inside of the migratory locust (Locusta migratoria). The results showed that the surface disinfection of test locusts contributed to the pathogenicity of B. bassiana to locusts. Most of the surface bacteria of L. migratoria caused some inhibition of B. bassiana growth, and LM5-4 (Raoultella ornithinolytica), LM5-2 (Enterobacter aerogenes), and LM5-13 (Citrobacter freundii) showed the highest inhibitory effect on the growth of B. bassiana. The inoculation of locusts with additional surface symbiotic bacteria reduced the virulence of B. bassiana to L. migratoria. Infection by different strains of B. bassiana caused similar changes in the symbiotic flora of migratory locusts. The inoculation of locusts with additional intestinal symbiotic bacteria (Enterobacter sp.) reduced the virulence of B. bassiana to L. migratoria. These findings illustrate the effect of bacterial communities on fungal infections in L. migratoria when seen from the perspective of ecology in a microenvironment. The active antifungal substances of such bacteria and their mechanisms of action need further study.

Febrile illnesses constitute a major clinical challenge in tropical settings. We aimed to assess the frequency, presentation and management of febrile illness at two health facilities in Forécariah, Guinea, with a focus on appropriateness of antibiotic prescription. This was a retrospective study conducted in patient files in a health center and a district hospital. Proportions of antibiotic prescription were determined by age group and syndromes as well as appropriateness of antibiotic prescription using the WHO model list (2019). From 2014 to 2020, 23,583 of 62,185 (38.0%) visits were related to febrile illness. Most patients with fever were female (56.1%) and evaluated at the health center (81.0%). Gastrointestinal (40.6%) and respiratory syndromes (36.8%), and undifferentiated fever (30.0%) were the most common presentations. Malaria was confirmed in 61.3% of the cohort. Overall, the rate of antibiotic prescription was high (14,834/23,583, 62.9%), mostly among patients aged <5 years (5,285/7,566, 69.9%), those with respiratory (7,577/8,684, 87.3%) and gastrointestinal (6,324/9,585, 66.0%) syndromes. Moreover, 7,432/14,465 (51.4%) patients with malaria were also prescribed an antibiotic. Penicillin (42.0%), cotrimoxazole (26.3%) and quinolones (18.7%) were the most frequently prescribed antibiotics. Overall, appropriateness of antibiotic prescription was low (38.3%), and even more so in patients with respiratory (29.1%) and gastrointestinal (25.8%) syndromes. Febrile illness is a major cause of consultation in rural Guinea. Rate of antibiotic prescription was high, even in confirmed malaria and was often considered inappropriate. There is a pressing need to investigate the etiological spectrum and improve the diagnostic approach of febrile illness in Guinea.

The viscoelastic and the structure properties of three brands of dry sausages (Auvergne, Beef-poultry, and Galbanetto) were studied using dynamic rheology and fluorescence spectroscopy. The storage and the loss modulus of sausage samples showed a viscoelastic character. The principal component analysis carried out on the normalized rheological and physico-chemical parameters allowed to differentiate the sausage samples into three groups according to their brands. This trend was confirmed by the factorial discriminant analysis where 74.44% of correct classification was obtained. The emission spectra acquired after excitation set at 290, 340, and 360 nm and excitation spectra scanned after emission set at 410 nm allowed clear differentiation between the three brand samples. The obtained results were confirmed following the application of partial least squares regression to the fluorescence and physico-chemical parameters since an excellent prediction of moisture content was obtained from the excitation spectra set at 340 nm (R2 =0.99) and 360 nm (R2 =0.99). The protein content of dry sausages was well predicted after excitation set at 290 and 340 nm with R2 of 0.96 and 0.97, respectively, while the fat level was well estimated after excitation set at 340 and 360 nm and emission set at 410 nm (R2 =0.96, 0.96 and 0.94, respectively). The obtained results showed the potential use of fluorescence spectroscopy as a rapid technique for evaluating the quality of dry sausages.

BackgroundBeauveria bassiana (Bals.) (Hypocreales: Cordycipitaceae) is an entomopathogenic fungus that has potential as a biological control agent against many insect pests. This study was conducted to optimize the conditions for large-scale production on rice of B. bassiana and evaluate its virulence against the bean flower thrips Megalurothrips usitatus (Bagnall) (Thysanoptera: Thripidae).ResultsThe optimal substrate quantity for conidia production was 200 g of rice per container (2.1 l), with substrate having a 52% moisture content, being supplemented with 2% cooking oil. In stage production of a batch, 150 ml of conidia suspension (at 24.33 × 107 spores/ml) was incubated for 10 days in SDA liquid medium amended with 4% glucose and 1.5% yeast extract. The SDA medium was then used to inoculate one container of the rice substrate. The optimum ratio of conidial suspension to substrate (v/v) was 20–25%. Virulence of the spore powder harvested from the rice substrate was same as that of produced on the SDA solid media against thrips. The level of control from an application of spore powder of the thrips M. usitatus was similar to that from chemical the pesticide spinetoram when applied in a cowpea (Vigna sinensis Endl) field.ConclusionsThe optimized rice substrate system can be used for a large-scale production of B. bassiana spores, which can be used for field control of thrips.

Simple SummaryIn vector control programs based on the sterile insect technique (SIT), the biological quality of sterile males must be as high as possible to compete with their wild counterparts. This study evaluates the biological quality and mating performance of sterile male Glossina palpalis gambiensis produced in a mass-rearing facility in Burkina Faso. It shows that irradiation had no effect on the adult emergence rate but reduced the percentage of operational flies and male fly survival. Irradiation had no effect on mating performances, as all females were inseminated, and the sterile males competed well with unirradiated males for virgin females in walk-in field cages. However, the sterility rate induced in females was lower than expected (89.67%). This study indicates that, under experimental field cage conditions, the G. p. gambiensis males produced at the CIRDES are well-suited for use in area-wide integrated pest management (AW-IPM) programs that have an SIT component. The reduction in the sterility rate highlights the importance of regularly monitoring the biological parameters of sterile males and the radiation source.The biological quality of sterile male insects produced in a mass-rearing facility is a prerequisite for the success of the SIT, which is a component of area-wide integrated pest management (AW-IPM). Indeed, sterile male insects released in the field must have a good mating performance in order to compete with wild males, but they must also present the required level of sterility. In the present study, the biological quality of sterile male Glossina palpalis gambiensis produced in a mass-rearing insectary was assessed through quality control testing. The mating performance of irradiated males was assessed in walk-in field cages. Irradiation had no effect on adult emergence but significantly reduced the percentage of operational flies (from 89.58% to 79.87%) and male survival (from 5 to 4 days, on average). However, irradiation did not impact the sterile male insemination potential, with all females inseminated and more than 80% of the spermathecae completely filled. The rate of induced sterility in females was 89.67% due to a dose rate decrease of the radiation source. Moreover, sterile males were able to compete successfully with untreated fertile males for untreated females in walk-in field cages. This study confirmed that the flies were still competitive and stressed the importance of regularly checking the radiation source parameters.

High solids anaerobic digestion (AD) of chicken manure (CM) is often challenging due to ammonia-N inhibition and accumulation of volatile fatty acids (VFAs). This study evaluated the effect of adding biochars from different feedstock to ameliorate semi-dry AD of fresh CM during batch fermentation. Experiments were performed in 300 mL at two total solid (TS) levels (12% and 15%) under mesophilic (36 ±1ᵒC) conditions for 55 d, using activated sludge as inoculum. Treatments included: fresh CM (at 12% or 15% TS) mixed separately with rice husks char (RB), wood char (WB) and bamboo char (BB) at biochar dosages of 2.5%, 5% and 10% of TS in the CM, inoculum only and inoculum plus CM without addition of char as the control. Results indicated that addition of biochar reduced the lag phases to 4–5.4 d and AD performances were significantly improved with total volatile solids removal of 53–67% and 62–71%, and cumulative methane of 277–380 mL/gVS (CH4 content ≈ 51–63%) and 297–438 mL/gVS (CH4 content ≈ 49–67%) at 12% and 15% TS, respectively. Biochar buffered over acidification and stabilized pH in the range of 6.5–7.8 but mild ammonia inhibition still occurred in all biochar treatments due to the high residual total ammonia-N (4.3 g–5.6 g/L). For all the investigated parameters, WB amended digesters exhibited the best results owing to its high specific surface area, porosity, cationic exchange capacity, and elemental composition which were superior to those of RB and BB. At 10% dosage of all tested biochars, the AD process was more stable and methane content neared optimal of >65% CH4. Therefore, addition of biochar from lignocellulosic materials at a given threshold dosage could promote semi-dry and dry biogas production from chicken manure and thus add value to this waste which in most cases is improperly managed.