Cyclic lipopeptide-producing Pseudomonas koreensis group strains dominate the cocoyam rhizosphere of a Pythium root rot suppressive soil contrasting with P. putida prominence in conducive soils

Pseudomonas isolates from tropical environments have been underexplored and may form an untapped reservoir of interesting secondary metabolites. In this study, we compared Pseudomonas and cyclic lipopeptide (CLP) diversity in the rhizosphere of a cocoyam root rot disease (CRRD) suppressive soil in Boteva, Cameroon with those from four conducive soils in Cameroon and Nigeria. Compared with other soils, Boteva andosols were characterized by high silt, organic matter, nitrogen and calcium. Besides, the cocoyam rhizosphere at Boteva was characterized by strains belonging mainly to the P. koreensis and P. putida (sub)groups, with representations in the P. fluorescens, P. chlororaphis, P. jessenii and P. asplenii (sub)groups. In contrast, P. putida isolates were prominent in conducive soils. Regarding CLP diversity, Boteva was characterized by strains producing 11 different CLP types with cocoyamide A producers, belonging to the P. koreensis group, being the most abundant. However, putisolvin III-V producers were the most dominant in the rhizosphere of conducive soils in both Cameroon and Nigeria. Furthermore, we elucidated the chemical structure of putisolvin derivatives—putisolvin III-V, and described its biosynthetic gene cluster. We show that high Pseudomonas and metabolic diversity may be driven by microbial competition, which likely contributes to soil suppressiveness to CRRD.     

Heat-Induced Conformational Unfolding of Fatty Acid-Free and Fatted Camel Serum Albumin: A Comparative Study

Albumin is a multifunctional non-glycosylated, negatively charged plasma protein, with extraordinary ligand-binding and transport properties, antioxidant functions, and enzymatic activities. Physiologically, albumin transports free fatty acids in plasma and contributes in maintaining colloid osmotic pressure. Recent progresses in using albumin as a versatile protein carrier for drug targeting and for improving the pharmacokinetic profile of peptide or protein-based drugs, increased the attempts for improving albumin stability. Studying the thermal stability of camel albumin may provide us not only new clues for designing recombinant albumins, but also molecular insights on camel physiology. This study aims to determine the thermal stability of camel albumin. Fatted camel serum albumin (FCSA) was purified from blood via combination of Cohn’s method and anion-exchange chromatography. Activated charcoal treatment was used to obtain defatted camel serum albumin (CSA). Fluorescence spectroscopy and differential scanning calorimetry (DSC) were used to study thermal denaturation of this protein. The set of fluorescence spectra were deconvoluted using the convex constraint analysis method (CCA). The results from deconvolution of fluorescence spectroscopy and DSC showed three and two components for CSA and FCSA, respectively. The bimodal DSC transition can be attributed to a crevice between domains I and II and formation of two independent thermodynamic domains. The crevice formation can be prevented by fatty acid binding between domains I and II. The calculated values of ?H _v/?H _cal, approximately 0.4 for CSA and near 1 for FCSA, confirmed the presence of at least one intermediate in thermal unfolding of CSA and the absence of the intermediate for FCSA. The obtained midpoint transition temperature (T _m) of FCSA was about 20 °C higher than that of CSA. Such enormous stabilizing effect may be attributed to the fact that fatty acid serves as glue which preserves different domains beside each other and prevents formation of the mentioned intermediate.     

Oxidative enzymes activities of mycorrhizal inoculated pepper plant infected with phytophthora infestans

The activities of polyphenol oxidase, peroxidase and catalase were investigated in Glomus etunicatum an arbuscular mycorrhizal inoculated pepper plant infected with Phytophthora infestans. Pepper plant inoculated with pathogen alone, simultaneously inoculated with mycorrhizal and pathogen or dually inoculated with pathogen before mycorrhizal had increased level of the oxidative enzymes activities especially at 4 weeks after planting. Of the three oxidases investigated catalase had the highest level of activities in all the treatments while the level of peroxidase was the lowest. The results showed that pathogen alone, build up the level of the oxidases in the inoculated pepper plant while inoculation of the pepper plant with AM mycorrhizal either simultaneously or dually with pathogen lower the activity of the oxidases indicating a passive protective effect of mycorrhizal.     

Stress and coping among mothers of twins in rural southwestern Nigeria.

High rates of twinning have been reported in Africa. This study sought to learn whether mothers of twins experience different stress levels than those who have only singletons. Both twin mothers (101) and singleton mothers (101) were interviewed. Using a scale of 15 stressors the researchers found that the mean stress score was significantly higher for twin mothers than singleton mothers. Higher stress scores were also associated with parity and perceptions of problems in caring for children and inversely related to perceived levels of social support. Confronting stressors or simply accepting them were the two main ways that mothers coped with their problems.     

Assessment of the Quality of Antenatal Care Services Provided by Health Workers Using a Mobile Phone Decision Support Application in Northern Nigeria: A Pre/Post-Intervention Study

BackgroundGiven the shortage of skilled healthcare providers in Nigeria, frontline community health extension workers (CHEWs) are commonly tasked with providing maternal and child health services at primary health centers. In 2012, we introduced a mobile case management and decision support application in twenty primary health centers in northern Nigeria, and conducted a pre-test/post-test study to assess whether the introduction of the app had an effect on the quality of antenatal care services provided by this lower-level cadre.MethodsUsing the CommCare mobile platform, the app dynamically guides CHEWs through antenatal care protocols and collects client data in real time. Thirteen health education audio clips are also embedded in the app for improving and standardizing client counseling. To detect changes in quality, we developed an evidence-based quality score consisting of 25 indicators, and conducted a total of 266 client exit interviews. We analyzed baseline and endline data to assess changes in the overall quality score as well as changes in the provision of key elements of antenatal care.ResultsOverall, the quality score increased from 13.3 at baseline to 17.2 at endline (p<0.0001), out of a total possible score of 25, with the most significant improvements related to health counseling, technical services provided, and quality of health education.ConclusionThese study results suggest that the introduction of a low-cost mobile case management and decision support application can spur behavior change and improve the quality of services provided by a lower level cadre of healthcare workers. Future research should employ a more rigorous experimental design to explore potential longer-term effects on client health outcomes.     

Electrospray Production of Curcumin-walnut Protein Nanoparticles

Electrospray technique was applied to produce nanoparticles (NPs) from walnut protein isolate (WPI) in order to encapsulate curcumin. The optimized condition for the production of the WPI NPs was WPI concentration of 3.5%, a solvent mixture of deionized water: 2-propanol (2:1, v/v), electrospraying at a fixed distance, voltage and flow rate including 17.5 cm, 20 kV and 0.09 mL/h, respectively. The ratio of curcumin to WPI was 1:100 (w/w), and the encapsulation efficiency was around 61.5%. The addition of curcumin to WPI solution affected the size, form and surface properties of the electrosprayed NPs. FESEM, HRTEM, AFM, XRD, FT-IR and fluorescence spectroscopy, were applied for the characterization of the produced NPs via electrospraying. The in vitro study revealed that release of curcumin was limited in the stomach due to the protective effect of WPI NPs. In the small intestine, WPI particles were hydrolyzed and curcumin was released. Furthermore, the antioxidant activity of curcumin-WPI NPs after in vitro digestion was significantly higher than WPI NPs due to the bioactive peptides released from WPI NPs. It can be concluded that WPI NPs could act as a unique food-grade carrier to boost the solubility of curcumin.