20 research outputs found

    Bud development, flowering and fruit set of Moringa oleifera Lam. (Horseradish Tree) as affected by various irrigation levels

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    Moringa oleifera is becoming increasingly popular as an industrial crop due to its multitude of useful attributes as water purifier, nutritional supplement and biofuel feedstock. Given its tolerance to sub-optimal growing conditions, most of the current and anticipated cultivation areas are in medium to low rainfall areas. This study aimed to assess the effect of various irrigation levels on floral initiation, flowering and fruit set. Three treatments namely, a 900 mm (900IT), 600 mm (600IT) and 300 mm (300IT) per annum irrigation treatment were administered through drip irrigation, simulating three total annual rainfall amounts. Individual inflorescences from each treatment were tagged during floral initiation and monitored throughout until fruit set. Flower bud initiation was highest at the 300IT and lowest at the 900IT for two consecutive growing seasons. Fruit set on the other hand, decreased with the decrease in irrigation treatment. Floral abortion, reduced pollen viability as well as moisture stress in the style were contributing factors to the reduction in fruiting/yield observed at the 300IT. Moderate water stress prior to floral initiation could stimulate flower initiation, however, this should be followed by sufficient irrigation to ensure good pollination, fruit set and yield

    Repeated exposure of jacket plum (Pappea capensis) micro-cuttings to indole-3-butyric acid (IBA) improved in vitro rooting capacity

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    The objective of the trial was to determine an effective propagation protocol for jacket plum (Pappea capensis) tree species. Experiments on in vitro propagation and rooting of stem cuttings were carried out. Dipping stem cuttings in half strength Murashige and Skoog (MS) media for 12 h prior to application of rooting hormones improved bud break and prolonged survival of stem cuttings on a mist bed. Early leaf loss was observed for stem cuttings planted without MS treatment. However, rooting was poor (11% for cuttings pre-treated in MS and 0% for those not pre-treated). For micro-propagation, significant differences (P < 0.05) in shoot multiplication and root regeneration were found. MS media supplemented with 2.0 mg l–1 benzylaminopurine was superior in the number of micro-shoots produced. Rooting capacity of micro-cuttings was improved from 42% to 64% when MS media supplemented with 0.5 mg l–1 IBA were repeated for the micro-cuttings that initially failed to root. There was 70% survival rate of plantlets after hardened off.The financial support from the Federal Ministry of Economic Cooperation (BMZ/GTZ), Germany through the World Agroforestry Centre (ICRAF) Southern Africa Regional Programme, Agro-Forest and Bio Energy Association and Invest North West, South Africa is acknowledged

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

    An Investigation into Using Temporary Immersion Bioreactors to Micropropagate Moringa oleifera Lam. Callus, Roots, and Shoots

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    Moringa oleifera Lam., a tree naturally grown in the tropics, is becoming increasingly popular as an industrial crop due to its multitude of useful attributes. Therefore, this study tested the effect of temporary immersion system (TIS) bioreactors for mass micropropagation of Moringa oleifera Lam. callus, roots, and shoots. TIS are tissue culture systems that make use of timers to periodically immerse and drain plant cultures in a liquid nutrient medium instead of using solidified media. In initial studies, Moringa oleifera seeds were germinated in vitro, and in vitro seedling leaflets were then used as explant material for callus production on the pre-culturing media. Two experiments were conducted to improve the protocol for TIS bioreactor production. The first experiment investigated the effect of 6-benzylaminopurine (BA) and kinetin, whereas experiment 2 was conducted to improve shooting production. For the first experiment, leaf material was cultured onto a solidified medium consisting of half-strength Murashige and Skoog (MS) basal salts and 0.5 ppm 1-naphthaleneacetic acid (NAA) to initiate callus production before splitting it between solidified media and bioreactors for shooting. The shooting media consisted of full-strength MS basal salts and different treatments of kinetin and BA. A significant increase in callus production was observed with the use of TIS bioreactors, compared to solidified media, whereas root production had a highly significant interaction effect between the media and the cytokinin treatments. With shoot proliferation in mind, experiment 2 was performed, where microcuttings from in vitro-grown seedlings were excised and cultured onto a solidified MS medium, consisting of a control (0 ppm BA) and two different concentrations of 6-benzylaminopurine (BA) (0.1 ppm BA and 0.2 ppm BA) in the pre-culturing phase. Microcuttings were again excised after two weeks and transferred to the shooting media containing 0.1 ppm BA in TIS bioreactors and semi-solidified medium. Results showed TIS bioreactors to be effective in increasing both the amount and length of shoots produced. Shoot and callus fresh weights were also higher in explants cultured in TIS bioreactors. The results of this study also suggest M. oleifera sensitivities to plant growth regulators (PGRs). In conclusion, this study successfully produced callus, roots, and shoots in both the solidified media and TIS bioreactors, emphasizing the prospect of using TIS bioreactors for mass micropropagation of M. oleifera callus, roots, and shoots

    NMR-Based Metabolomic Analyses to Identify the Effect of Harvesting Frequencies on the Leaf Metabolite Profile of a Moringa oleifera Cultivar Grown in an Open Hydroponic System

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    Moringa oleifera Lam. is one of the world’s most useful medicinal plants. Different parts of the M. oleifera tree contain a rich profile of important minerals, proteins, vitamins, and various important bioactive compounds. However, there are differences in the phytochemical composition of the medicinal plant’s raw materials due to seasonal variation, cultivation practices, and post-harvest processing. The main objective of this study was therefore to determine the effect of harvesting frequencies on selected bioactive compounds of a M. oleifera cultivar (PKM1) grown in a hydroponic system under a shade net structure. Three harvesting frequency treatments were applied in the study, with the plants harvested at every 30 days (high frequency), 60 days (intermediate frequency), and 90 days (low frequency) respectively. 1H-NMR was used for data acquisition, and multivariate data analysis by means of principal component analysis (PCA), partial least square discriminatory analysis (PLS-DA), and orthogonal partial least square discriminatory analysis (OPLS-DA) were applied to determine the changes in the leaf metabolite profile, and also to identify the spectral features contributing to the separation of samples. Targeted metabolite analysis was used to match the NMR peaks of the compounds with the NMR chemical shifts of the contribution plot. The contribution plot showed that the increase in concentration of some compounds in aliphatic, sugar and aromatic regions contributed to the separation of the samples. The results revealed that intermediate and low harvesting frequencies resulted in a change in the leaf metabolite profile. Compounds such as chlorogenic acid, ferulic acid, vanillic acid, wogonin, esculetin, niazirin, and gamma-aminobutyric acid (GABA) showed an increase under intermediate and low harvesting frequencies. These results provide insight into the effect of harvesting frequencies on the metabolite profile and associated medicinal activity of M. oleifera

    The phenolic, 3,4-dihydroxybenzoic acid, is an endogenous regulator of rooting in Protea cynaroides

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    Analysis of stem extracts identified large quantities of 3,4-dihydroxybenzoic acid and other similar phenolics. The exogenous application of 3,4-dihydroxybenzoic acid on Protea cynaroides explants in vitro significantly increased the root mass at 100 mg l-1, but not at lower concentrations, while root inhibition was observed at 500 mg l-1. HPLC analysis of cuttings during vegetative propagation showed a considerable increase in 3,4-dihydroxybenzoic acid levels from initial planting to when root formation took place, indicating for the first time that 3,4-dihydroxybenzoic acid may be an important phenolic compound in regulating root formation in P. cynaroides cuttings. HPLC analysis also identified caffeic, ferulic, gallic and salicylic acids in the cuttings. © 2007 Springer Science+Business Media B.V
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