Selection of plant growth promoting rhizobacteria sharing suitable features to be commercially developed as biostimulant products

Plant biostimulants (PBs) are an eco-friendly alternative to chemical fertilisers because of their minimal or null impact on human health and environment, while ensuring optimal nutrient uptake and increase of crop yield, quality and tolerance to abiotic stress. Although there is an increasing interest on microbial biostimulants, the optimal procedure to select and develop them as commercial products is still not well defined. This work proposes and validates a procedure to select the best plant growth promoting rhizobacteria (PGPR) as potential active ingredients of commercial PBs. The stepwise screening strategy was designed based on literature analysis and consists of six steps: (i) determination of the target crop and commercial strategy, (ii) selection of growth media for the isolation of microbial candidates, (iii) screening for traits giving major agronomical advantages, (iv) screening for traits related to product development, (v) characterisation of the mode of action of PGPR and (vi) assessment of plant growth efficacy. The strategy was validated using a case study: PGPR combined with humic acids to be applied on tomato plants. Among 200 bacterial strains isolated from tomato rhizosphere, 39 % were able to grow in presence of humic acids and shared the ability to solubilise phosphate. After the screening for traits related to product development, only 6 % of initial bacterial strains were sharing traits suitable for the further development as potential PBs. In fact, the selected bacterial strains were able to produce high cell mass and tolerated drought, aspects important for the mass production and formulation. These bacterial strains were not able to produce antibiotics, establish pathogenic interaction with plants and did not belong to bacterial species associated to human, animal and plant diseases. Most importantly, five of the selected bacterial strains were able to promote tomato seedling vigour in experiments carried out in vitro. These bacterial strains were furtherly characterised for their ability to colonize effectively tomato plant roots, produce phytohormones and solubilise soil minerals. This characterisation led to the selection of two candidates that showed the ability to promote tomato plant growth in experiments carried out in greenhouse conditions. Overall, this work provides a flow diagram for the selection of PGPR candidates to be successfully developed and commercialized as PBs. The validation of the flow diagram led to the selection of two bacterial strains belonging to Pantoea and Pseudomonas genera, potential active ingredients of new commercial PBs

Peripheral reductive capacity is associated with cognitive performance and survival in Alzheimer's disease

BACKGROUND: Oxidative stress is believed to be an early event and a key factor in Alzheimer's disease (AD) pathogenesis and progression. In spite of an intensive search for surrogate markers to monitor changes related to oxidative stress in the brain, there is as yet no consensus about which markers to use in clinical studies. The measurement of peripheral anti-oxidants is an alternative way of evaluating the involvement of oxidative stress in the course of the disease. Given the complexity of peripheral anti-oxidant defence, variations in the levels of individual anti-oxidant species may not fully reflect the overall capacity to fight oxidant conditions. We therefore chose to evaluate the total reductive capacity (herein defined as anti-oxidant capacity, AOC) in serum from control subjects and AD patients in order to study the association between peripheral anti-oxidant defence, cognitive impairment and patient survival. METHODS: We measured the levels of AOC in serum samples from 26 cognitively normal controls and 25 AD patients (12 post-mortem confirmed) who completed the Cambridge Cognitive Assessment. Cognitive decline was assessed in a subgroup of 19 patients who underwent a second cognitive assessment 2 years after the initial visit. RESULTS: Serum AOC levels were lower in AD patients than in controls and were correlated with their cognitive test scores, although AOC levels were unrelated to cognitive decline assessed two years later. On the other hand, AOC levels were predictive of the length of patients' survival, with higher levels giving longer survival. CONCLUSION: This study indicates that peripheral anti-oxidant defences are depleted in AD patients. The results suggest that serum AOC is a good index of the general health status and prognosis of patients but does not necessarily reflect the extent to which vulnerable neuronal populations are protected from oxidant processes. Further studies are required to establish whether peripheral AOC measurements may be useful in identifying asymptomatic individuals or those with early symptoms at high risk of developing significant cognitive impairment or dementia

Ecological role of volatile organic compounds emitted by Pantoea agglomerans as interspecies and interkingdom signals

Volatile organic compounds (VOCs) play an essential role in microbe–microbe and plant–microbe interactions. We investigated the interaction between two plant growth-promoting rhizobacteria, and their interaction with tomato plants. VOCs produced by Pantoea agglomerans MVC 21 modulates the release of siderophores, the solubilisation of phosphate and potassium by Pseudomonas (Ps.) putida MVC 17. Moreover, VOCs produced by P. agglomerans MVC 21 increased lateral root density (LRD), root and shoot dry weight of tomato seedlings. Among the VOCs released by P. agglomerans MVC 21, only dimethyl disulfide (DMDS) showed effects similar to P. agglomerans MVC 21 VOCs. Because of the effects on plants and bacterial cells, we investigated how P. agglomerans MVC 21 VOCs might influence bacteria–plant interaction. Noteworthy, VOCs produced by P. agglomerans MVC 21 boosted the ability of Ps. putida MVC 17 to increase LRD and root dry weight of tomato seedlings. These results could be explained by the positive effect of DMDS and P. agglomerans MVC 21 VOCs on acid 3-indoleacetic production in Ps. putida MVC 17. Overall, our results clearly indicated that P. agglomerans MVC 21 is able to establish a beneficial interaction with Ps. putida MVC 17 and tomato plants through the emission of DMD

Immune and Epstein-Barr virus gene expression in cerebrospinal fluid and peripheral blood mononuclear cells from patients with relapsing-remitting multiple sclerosis

Background: Gene expression analyses in paired cerebrospinal fluid (CSF) and peripheral blood mononuclear cells (PBMC) from patients with multiple sclerosis (MS) are restrained by the low RNA amounts from CSF cells and low expression levels of certain genes. Here, we applied a Taqman-based pre-amplification real-time reverse-transcription polymerase chain reaction (RT-PCR) (PreAmp RT-PCR) to cDNA from CSF cells and PBMC of MS patients and analyzed multiple genes related to immune system function and genes expressed by Epstein-Barr virus (EBV), a herpesvirus showing strong association with MS. Using this enhanced RT-PCR method, we aimed at the following: (1) identifying gene signatures potentially useful for patient stratification, (2) understanding whether EBV infection is perturbed in CSF and/or blood, and (3) finding a link between immune and EBV infection status. Methods: Thirty-one therapy-free patients with relapsing-remitting MS were included in the study. Paired CSF cells and PBMC were collected and expression of 41 immune-related cellular genes and 7 EBV genes associated with latent or lytic viral infection were determined by PreAmp RT-PCR. Clinical, radiological, CSF, and gene expression data were analyzed using univariate and multivariate (cluster analysis, factor analysis) statistical approaches. Results: Several immune-related genes were differentially expressed between CSF cells and PBMC from the whole MS cohort. By univariate analysis, no or only minor differences in gene expression were found associated with sex, clinical, or radiological condition. Cluster analysis on CSF gene expression data grouped patients into three clusters; clusters 1 and 2 differed by expression of genes that are related mainly to innate immunity, irrespective of sex and disease characteristics. By factor analysis, two factors grouping genes involved in antiviral immunity and immune regulation, respectively, accurately discriminated cluster 1 and cluster 2 patients. Despite the use of an enhanced RT-PCR method, EBV transcripts were detected in a minority of patients (5 of 31), with evidence of viral latency activation in CSF cells or PBMC and of lytic infection in one patient with active disease only. Conclusions: Analysis of multiple cellular and EBV genes in paired CSF cell and PBMC samples using PreAmp RT-PCR may yield new information on the complex interplay between biological processes underlying MS and help in biomarker identification

The Promotoer, a brain-computer interface-assisted intervention to promote upper limb functional motor recovery after stroke: a statistical analysis plan for a randomized controlled trial

Background: Electroencephalography (EEG)-based brain-computer interfaces (BCIs) allow to modulate the sensorimotor rhythms and are emerging technologies for promoting post-stroke motor function recovery. The Promotoer study aims to assess the short and long-term efficacy of the Promotoer system, an EEG-based BCI assisting motor imagery (MI) practice, in enhancing post-stroke functional hand motor recovery. This paper details the statistical analysis plan of the Promotoer study. Methods: The Promotoer study is a randomized, controlled, assessor-blinded, single-centre, superiority trial, with two parallel groups and a 1:1 allocation ratio. Subacute stroke patients are randomized to EEG-based BCI-assisted MI training or to MI training alone (i.e. no BCI). An internal pilot study for sample size re-assessment is planned. The primary outcome is the effectiveness of the Upper Extremity Fugl-Meyer Assessment (UE-FMA) score. Secondary outcomes include clinical, functional, and user experience scores assessed at the end of intervention and at follow-up. Neurophysiological assessments are also planned. Effectiveness formulas have been specified, and intention-to-treat and per-protocol populations have been defined. Statistical methods for comparisons of groups and for development of a predictive score of significant improvement are described. Explorative subgroup analyses and methodology to handle missing data are considered. Discussion: The Promotoer study will provide robust evidence for the short/long-term efficacy of the Promotoer system in subacute stroke patients undergoing a rehabilitation program. Moreover, the development of a predictive score of response will allow transferring of the Promotoer system to optimal clinical practice. By carefully describing the statistical principles and procedures, the statistical analysis plan provides transparency in the analysis of data. Trial registration: ClinicalTrials.gov NCT04353297 . Registered on April 15, 2020

Fusarium oxysporum f.sp. radicis-lycopersici induces distinct transcriptome reprogramming in resistant and susceptible isogenic tomato lines

8openInternationalItalian coauthor/editorBackground: Fusarium oxysporum f.sp. radicis-lycopersici (FORL) is one of the most destructive necrotrophic pathogens affecting tomato crops, causing considerable field and greenhouse yield losses. Despite such major economic impact, little is known about the molecular mechanisms regulating Fusarium oxysporum f.sp. radicis-lycopersici resistance in tomato. Results: A transcriptomic experiment was carried out in order to investigate the main mechanisms of FORL response in resistant and susceptible isogenic tomato lines. Microarray analysis at 15 DPI (days post inoculum) revealed a distinct gene expression pattern between the two genotypes in the inoculated vs non-inoculated conditions. A model of plant response both for compatible and incompatible reactions was proposed. In particular, in the incompatible interaction an activation of defense genes related to secondary metabolite production and tryptophan metabolism was observed. Moreover, maintenance of the cell osmotic potential after the FORL challenging was mediated by a dehydrationinduced protein. As for the compatible interaction, activation of an oxidative burst mediated by peroxidases and a cytochrome monooxygenase induced cell degeneration and necrosis. Conclusions: Our work allowed comprehensive understanding of the molecular basis of the tomato-FORL interaction. The result obtained emphasizes a different transcriptional reaction between the resistant and the susceptible genotype to the FORL challenge. Our findings could lead to the improvement in disease control strategies.openManzo, D.; Ferriello, F.; Puopolo, G.; Zoina, A.; D’Esposito, D.; Tardella, L.; Ferrarini, A.; Ercolano, M.R.Manzo, D.; Ferriello, F.; Puopolo, G.; Zoina, A.; D’Esposito, D.; Tardella, L.; Ferrarini, A.; Ercolano, M.R

A Randomized Placebo-Controlled Trial of Varenicline for Smoking Cessation Allowing Flexible Quit Dates

Introduction: Current smoking cessation guidelines recommend setting a quit date prior to starting pharmacotherapy. However, providing flexibility in the date of quitting may be more acceptable to some smokers. The objective of this study was to compare varenicline 1 mg twice daily (b.i.d.) with placebo in subjects using a flexible quit date paradigm after starting medication. Methods: In this double-blind, randomized, placebo-controlled international study, smokers of ≥10 cigarettes/day, aged 18-75 years, and who were motivated to quit were randomized (3:1) to receive varenicline 1 mg b.i.d. or placebo for 12 weeks. Subjects were followed up through Week 24. Subjects were instructed to quit between Days 8 and 35 after starting medication. The primary endpoint was carbon monoxide-confirmed continuous abstinence during Weeks 9-12, and a key secondary endpoint was continuous abstinence during Weeks 9-24. Results: Overall, 493 subjects were randomized to varenicline and 166 to placebo. Continuous abstinence was higher for varenicline than for placebo subjects at the end of treatment (Weeks 9-12: 53.1% vs. 19.3%; odds ratio [OR] 5.9; 95% CI, 3.7-9.4; p < .0001) and through 24 weeks follow-up (Weeks 9-24: 34.7% vs. 12.7%; OR 4.4; 95% CI, 2.6-7.5; p < .0001). Serious adverse events occurred in 1.2% varenicline (none were psychiatric) and 0.6% placebo subjects. Fewer varenicline than placebo subjects reported depression-related adverse events (2.3% vs. 6.7%, respectively). Conclusions: Varenicline 1 mg b.i.d. using a flexible quit date paradigm had similar efficacy and safety compared with previous fixed quit date studies. © The Author 2011. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco

Human transmissible spongiform encephalopathies in eleven countries: diagnostic pattern across time, 1993–2002

BACKGROUND: The objective of this study was to describe the diagnostic panorama of human transmissible spongiform encephalopathies across 11 countries. METHODS: From data collected for surveillance purposes, we describe annual proportions of deaths due to different human transmissible spongiform encephalopathies in eleven EUROCJD-consortium countries over the period 1993–2002, as well as variations in the use of diagnostic tests. Using logistic models we quantified international differences and changes across time. RESULTS: In general, pre-mortem use of diagnostic investigations increased with time. International differences in pathological confirmation of sporadic Creutzfeldt-Jakob disease, stable over time, were evident. Compared to their counterparts, some countries displayed remarkable patterns, such as: 1) the high proportion, increasing with time, of variant Creutzfeldt-Jakob disease in the United Kingdom, (OR 607.99 95%CI 84.72–4363.40), and France (OR 18.35, 95%CI 2.20–152.83); 2) high, decreasing proportions of iatrogenic Creutzfeldt-Jakob disease in France, (OR 5.81 95%CI 4.09–8.24), and the United Kingdom, (OR 1.54 95%CI 1.03–2.30); and, 3) high and stable ratios of genetic forms in Slovakia (OR 21.82 95%CI 12.42–38.33) and Italy (OR 2.12 95%CI 1.69–2.68). CONCLUSION: Considerable international variation in aetiological subtypes of human transmissible spongiform encephalopathies was evident over the observation period. With the exception of variant Creutzfeldt-Jakob disease and iatrogenic Creutzfeldt-Jakob disease in France and the United Kingdom, these differences persisted across time