Bacillus velezensis SQR9 promotes plant growth through colonization and rhizosphere-phyllosphere bacteria interaction

The rhizosphere and phyllosphere of plants are home to a diverse range of microorganisms that play pivotal roles in ecosystem services. Consequently, plant growth-promoting bacteria (PGPB) are extensively utilized as inoculants to enhance plant growth and boost productivity. Despite this, the interactions between the rhizosphere and phyllosphere, which are influenced by PGPB inoculation, have not been thoroughly studied to date. In this study, we inoculated Bacillus velezensis SQR9, a PGPB, into the bulk soil, rhizosphere or phyllosphere, and subsequently examined the bacterial communities in the rhizosphere and phyllosphere using amplicon sequencing. Our results revealed that PGPB inoculation increased its abundance in the corresponding compartment, and all treatments demonstrated plant growth promotion effects. Further analysis of the sequencing data indicated that the presence of PGPB exerted a more significant impact on bacterial communities in both the rhizosphere and phyllosphere than in the inoculation compartment. Notably, the PGPB stimulated similar rhizosphere-beneficial microbes regardless of the inoculation site. We, therefore, conclude that PGPB can promote plant growth both directly and indirectly through the interaction between the rhizosphere and phyllosphere, leading to the enrichment of beneficial microorganisms.

Predatory protists reduce bacteria wilt disease incidence in tomato plants

Soil organisms are affected by the presence of predatory protists. However, it remains poorly understood how predatory protists can affect plant disease incidence and how fertilization regimes can affect these interactions. Here, we characterise the rhizosphere bacteria, fungi and protists over eleven growing seasons of tomato planting under three fertilization regimes, i.e conventional, organic and bioorganic, and with different bacterial wilt disease incidence levels. We find that predatory protists are negatively associated with disease incidence, especially two ciliophoran Colpoda OTUs, and that bioorganic fertilization enhances the abundance of predatory protists. In glasshouse experiments we find that the predatory protist Colpoda influences disease incidence by directly consuming pathogens and indirectly increasing the presence of pathogen-suppressive microorganisms in the soil. Together, we demonstrate that predatory protists reduce bacterial wilt disease incidence in tomato plants via direct and indirect reductions of pathogens. Our study provides insights on the role that predatory protists play in plant disease, which could be used to design more sustainable agricultural practices.

Moderately delayed maturation of composting promotes the reduction of guild-plant pathogenic fungi within vegetable waste

The relationships among the relative abundance of guild-plant pathogenic fungi, compost maturation index, and microbial community variation during vegetable waste composting, which are influenced by the C/N ratio, remain poorly understood. To address this, fungal communities were analyzed in composting treatments with C/N ratios of approximately 15 (CN15) and 25 (CN25), using vegetable waste as the primary raw material. The CN15 treatment showed greater microbial community variation and a better overall compost maturation index value than the CN25 treatment. However, the CN25 treatment had a greater decline in plant-pathogenic fungi than the CN15 treatment. Notably, the relative abundance of guild-plant pathogenic fungi was significantly negatively related to the compost maturity index in the CN25 treatment, while no significant relationship was observed in the CN15 treatment. This study suggests that the moderately delayed maturation of composting is beneficial for reducing guild-plant pathogenic fungi in vegetable waste.

Biodiversity of the beneficial soil-borne fungi steered by Trichoderma-amended biofertilizers stimulates plant production

The soil microbiota is critical to plant performance. Improving the ability of plant-associated soil probiotics is thus essential for establishing dependable and sustainable crop yields. Although fertilizer applications may provide an effective way of steering soil microbes, it is still unknown how the positive effects of soil-borne probiotics can be maximized and how their effects are mediated. This work aims to seek the ecological mechanisms involved in cabbage growth using bio-organic fertilizers. We conducted a long-term field experiment in which we amended soil with non-sterilized organic or sterilized organic fertilizer either containing Trichoderma guizhouense NJAU4742 or lacking this inoculum and tracked cabbage plant growth and the soil fungal community. Trichoderma-amended bio-organic fertilizers significantly increased cabbage plant biomass and this effect was attributed to changes in the resident fungal community composition, including an increase in the relative abundance and number of indigenous soil growth-promoting fungal taxa. We specifically highlight the fundamental role of the biodiversity and population density of these plant-beneficial fungal taxa in improving plant growth. Together, our results suggest that the beneficial effects of bio-organic fertilizer seem to be a combination of the biological inoculum within the organic amendment as well as the indirect promotion through effects on the diversity and composition of the soil resident plant-beneficial fungal microbiome.

Rhizosphere Microbiota Promotes the Growth of Soybeans in a Saline-Alkali Environment under Plastic Film Mulching

The rhizosphere microbiota plays a critical and crucial role in plant health and growth, assisting plants in resisting adverse stresses, including soil salinity. Plastic film mulching is an important method to adjust soil properties and improve crop yield, especially in saline-alkali soil. However, it remains unclear whether and to what extent the association between these improvements and rhizosphere microbiota exists. Here, from a field survey and a greenhouse mesocosm experiment, we found that mulching plastic films on saline-alkali soil can promote the growth of soybeans in the field. Results of the greenhouse experiment showed that soybeans grew better in unsterilized saline-alkali soil than in sterilized saline-alkali soil under plastic film mulching. By detecting the variations in soil properties and analyzing the high-throughput sequencing data, we found that with the effect of film mulching, soil moisture content was effectively maintained, soil salinity was obviously reduced, and rhizosphere bacterial and fungal communities were significantly changed. Ulteriorly, correlation analysis methods were applied. The optimization of soil properties ameliorated the survival conditions of soil microbes and promoted the increase in relative abundance of potential beneficial microorganisms, contributing to the growth of soybeans. Furthermore, the classification of potential key rhizosphere microbial OTUs were identified. In summary, our study suggests the important influence of soil properties as drivers on the alteration of rhizosphere microbial communities and indicates the important role of rhizosphere microbiota in promoting plant performance in saline-alkali soil under plastic film mulching.

Additive fungal interactions drive biocontrol of Fusarium wilt disease

Host-associated fungi can help protect plants from pathogens, and empirical evidence suggests that such microorganisms can be manipulated by introducing probiotic to increase disease suppression. However, we still generally lack the mechanistic knowledge of what determines the success of probiotic application, hampering the development of reliable disease suppression strategies. We conducted a three-season consecutive microcosm experiment in which we amended banana Fusarium wilt disease-conducive soil with Trichoderma-amended biofertilizer or lacking this inoculum. High-throughput sequencing was complemented with cultivation-based methods to follow changes in fungal microbiome and explore potential links with plant health. Trichoderma application increased banana biomass by decreasing disease incidence by up to 72%, and this effect was attributed to changes in fungal microbiome, including the reduction in Fusarium oxysporum density and enrichment of pathogen-suppressing fungi (Humicola). These changes were accompanied by an expansion in microbial carbon resource utilization potential, features that contribute to disease suppression. We further demonstrated the disease suppression actions of Trichoderma-Humicola consortia, and results suggest niche overlap with pathogen and induction of plant systemic resistance may be mechanisms driving the observed biocontrol effects. Together, we demonstrate that fungal inoculants can modify the composition and functioning of the resident soil fungal microbiome to suppress soilborne disease.

Plant pathogen resistance is mediated by recruitment of specific rhizosphere fungi

Beneficial interactions between plants and rhizosphere microorganisms are key determinants of plant health with the potential to enhance the sustainability of agricultural practices. However, pinpointing the mechanisms that determine plant disease protection is often difficult due to the complexity of microbial and plant-microbe interactions and their links with the plant's own defense systems. Here, we found that the resistance level of different banana varieties was correlated with the plant's ability to stimulate specific fungal taxa in the rhizosphere that are able to inhibit the Foc TR4 pathogen. These fungal taxa included members of the genera Trichoderma and Penicillium, and their growth was stimulated by plant exudates such as shikimic acid, D-(-)-ribofuranose, and propylene glycol. Furthermore, amending soils with these metabolites enhanced the resistance of a susceptible variety to Foc TR4, with no effect observed for the resistant variety. In total, our findings suggest that the ability to recruit pathogen-suppressive fungal taxa may be an important component in determining the level of pathogen resistance exhibited by plant varieties. This perspective opens up new avenues for improving plant health, in which both plant and associated microbial properties are considered.

Root-Associated Antagonistic Pseudomonas spp. Contribute to Soil Suppressiveness against Banana Fusarium Wilt Disease of Banana

Members of the microbiotas colonizing the plant endophytic compartments and the surrounding bulk and rhizosphere soil play an important role in determining plant health. However, the relative contributions of the soil and endophytic microbiomes and their mechanistic roles in achieving disease suppression remain elusive. To disentangle the relative importance of the different microbiomes in the various plant compartments in inhibiting pathogen infection, we conducted a field experiment to track changes in the composition of microbial communities in bulk and rhizosphere soil and of root endophytes and leaf endosphere collected from bananas planted on Fusarium-infested orchards in disease-suppressive and disease-conducive soils. We found that the rhizosphere and roots were the two dominant plant parts whose bacterial communities contributed to pathogen suppression. We further observed that Pseudomonas was potentially a key organism acting as a pathogen antagonist, as illustrated by microbial community composition and network analysis. Subsequently, culturable pathogen-antagonistic Pseudomonas strains were isolated, and their potential suppressive functions or possible antibiosis in terms of auxin or siderophore synthesis and phosphate solubilization were screened to analyze the mode of action of candidate disease-suppressive Pseudomonas strains. In a follow-up in vivo and greenhouse experiment, we revealed that microbial consortia of culturable Pseudomonas strains P8 and S25 (or S36), isolated from banana plantlet rhizosphere and roots, respectively, significantly suppressed the survival of pathogens in the soil, manipulated the soil microbiome, and stimulated indigenous beneficial microbes. Overall, our study demonstrated that root-associated microbiomes, especially the antagonistic Pseudomonas sp. components, contribute markedly to soil suppression of banana Fusarium wilt. IMPORTANCE Soil suppression of Fusarium wilt disease has been proven to be linked with the local microbial community. However, the contribution of endophytic microbes to disease suppression in wilt-suppressive soils remains unclear. Moreover, the key microbes involving in Fusarium wilt-suppressive soils and in the endophytic populations have not been fully characterized. In this study, we demonstrate that root-associated microbes play vitally important roles in disease suppression. Root-associated Pseudomonas consortia were recognized as a key component in inhibiting pathogen abundance associated with the host banana plants. This finding is crucial to developing alternate strategies for soilborne disease management by harnessing the plant microbiome.

Partitioning the Effects of Soil Legacy and Pathogen Exposure Determining Soil Suppressiveness via Induced Systemic Resistance

Beneficial host-associated bacteria can assist plant protection against pathogens. In particular, specific microbes are able to induce plant systemic resistance. However, it remains largely elusive which specific microbial taxa and functions trigger plant immune responses associated with disease suppression. Here, we experimentally studied this by setting up two independent microcosm experiments that differed in the time at which plants were exposed to the pathogen and the soil legacy (i.e., soils with historically suppressive or conducive). Overall, we found soil legacy effects to have a major influence on disease suppression irrespective of the time prior to pathogen exposure. Rhizosphere bacterial communities of tomato plants were significantly different between the two soils, with potential beneficial strains occurring at higher relative abundances in the suppressive soil. Root transcriptome analysis revealed the soil legacy to induce differences in gene expression, most importantly, genes involved in the pathway of phenylpropanoid biosynthesis. Last, we found genes in the phenylpropanoid biosynthesis pathway to correlate with specific microbial taxa, including Gp6, Actinomarinicola, Niastella, Phaeodactylibacter, Longimicrobium, Bythopirellula, Brevundimonas, Ferruginivarius, Kushneria, Methylomarinovum, Pseudolabrys, Sphingobium, Sphingomonas, and Alterococcus. Taken together, our study points to the potential regulation of plant systemic resistance by specific microbial taxa, and the importance of soil legacy on disease incidence and eliciting plant-defense mechanisms.

Soil antibiotic abatement associates with the manipulation of soil microbiome via long-term fertilizer application

The effects of different fertilization on microbial communities and resistome in agricultural soils with a history of fresh manure application remains largely unclear. Here, soil antibiotic resistance genes (ARGs), mobile genetic elements (MGEs) and microbial communities were deciphered using metagenomics approach from a long-term field experiment with different fertilizer inputs. A total of 541 ARG subtypes were identified, with Multidrug, Macrolides-Lincosamides-Streptogramins (MLS), and Bacitracin resistance genes as the most universal ARG types. The abundance of ARGs detected in manure (2.52 ARGs/16 S rRNA) treated soils was higher than chemical fertilizer (2.42 ARGs/16 S rRNA) or compost (2.37 ARGs/16 S rRNA) amended soils. The higher abundance of MGEs and the enrichment of Proteobacteria were observed in manure treated soils than in chemical fertilizer or compost amended soils. Proteobacter and Actinobacter were recognized as the main potential hosts of ARGs revealed by network analysis. Further soil pH was identified as the key driver in determining the composition of both microbial community and resistome. The present study investigated the mechanisms driving the microbial community, MGEs and ARG profiles of long-term fertilized soils with ARGs contamination, and our findings could support strategies to manage the dissemination of soil ARGs.

Shared Core Microbiome and Functionality of Key Taxa Suppressive to Banana Fusarium Wilt

Microbial contributions to natural soil suppressiveness have been reported for a range of plant pathogens and cropping systems. To disentangle the mechanisms underlying suppression of banana Panama disease caused by Fusarium oxysporum f. sp. cubense tropical race 4 (Foc4), we used amplicon sequencing to analyze the composition of the soil microbiome from six separate locations, each comprised of paired orchards, one potentially suppressive and one conducive to the disease. Functional potentials of the microbiomes from one site were further examined by shotgun metagenomic sequencing after soil suppressiveness was confirmed by greenhouse experiments. Potential key antagonists involved in disease suppression were also isolated, and their activities were validated by a combination of microcosm and pot experiments. We found that potentially suppressive soils shared a common core community with relatively low levels of F. oxysporum and relatively high proportions of Myxococcales, Pseudomonadales, and Xanthomonadales, with five genera, Anaeromyxobacter, Kofleria, Plesiocystis, Pseudomonas, and Rhodanobacter being significantly enriched. Further, Pseudomonas was identified as a potential key taxon linked to pathogen suppression. Metagenomic analysis showed that, compared to the conducive soil, the microbiome in the disease suppressive soil displayed a significantly greater incidence of genes related to quorum sensing, biofilm formation, and synthesis of antimicrobial compounds potentially active against Foc4. We also recovered a higher frequency of antagonistic Pseudomonas isolates from disease suppressive experimental field sites, and their protective effects against banana Fusarium wilt disease were demonstrated under greenhouse conditions. Despite differences in location and soil conditions, separately located suppressive soils shared common characteristics, including enrichment of Myxococcales, Pseudomonadales, and Xanthomonadales, and enrichment of specific Pseudomonas populations with antagonistic activity against the pathogen. Moreover, changes in functional capacity toward an increase in quorum sensing, biofilm formation, and antimicrobial compound synthesizing involve in disease suppression.

Trophic interactions between predatory protists and pathogen-suppressive bacteria impact plant health

Plant health is strongly impacted by beneficial and pathogenic plant microbes, which are themselves structured by resource inputs. Organic fertilizer inputs may thus offer a means of steering soil-borne microbes, thereby affecting plant health. Concurrently, soil microbes are subject to top-down control by predators, particularly protists. However, little is known regarding the impact of microbiome predators on plant health-influencing microbes and the interactive links to plant health. Here, we aimed to decipher the importance of predator-prey interactions in influencing plant health. To achieve this goal, we investigated soil and root-associated microbiomes (bacteria, fungi and protists) over nine years of banana planting under conventional and organic fertilization regimes differing in Fusarium wilt disease incidence. We found that the reduced disease incidence and improved yield associated with organic fertilization could be best explained by higher abundances of protists and pathogen-suppressive bacteria (e.g. Bacillus spp.). The pathogen-suppressive actions of predatory protists and Bacillus spp. were mainly determined by their interactions that increased the relative abundance of secondary metabolite Q genes (e.g. nonribosomal peptide synthetase gene) within the microbiome. In a subsequent microcosm assay, we tested the interactions between predatory protists and pathogen-suppressive Bacillus spp. that showed strong improvements in plant defense. Our study shows how protistan predators stimulate disease-suppressive bacteria in the plant microbiome, ultimately enhancing plant health and yield. Thus, we suggest a new biological model useful for improving sustainable agricultural practices that is based on complex interactions between different domains of life.

Organic fertilization enhances the resistance and resilience of soil microbial communities under extreme drought

INTRODUCTION

The soil bacterial microbiome plays a crucial role in ecosystem functioning. The composition and functioning of the microbiome are tightly controlled by the physicochemical surrounding. Therefore, the microbiome is responsive to management, such as fertilization, and to climate change, such as extreme drought. It remains a challenge to retain microbiome functioning under drought.

OBJECTIVES

This work aims to reveal if fertilization with organic fertilizer, can enhance resistance and resilience of bacterial communities and their function in extreme drought and subsequent rewetting compared with conventional fertilizers.

METHODS

In soil mesocosms, we induced a long-term drought for 80 days with subsequent rewetting for 170 days to follow bacterial community dynamics in organic (NOF) and chemical (NCF) fertilization regimes.

RESULTS

Our results showed that bacterial diversity was higher with NOF than with NCF during drought. In particular, the ecological resilience and recovery of bacterial communities under NOF were higher than in NCF. We found these bacterial community features to enhance pathogen-inhibiting functions in NOF compared to NCF during late recovery. The other soil ecology functional analyses revealed that bacterial biomass recovered in the early stage after rewetting, while soil respiration increased continuously following prolonged time after rewetting.

CONCLUSION

Together, our study indicates that organic fertilization can enhance the stability of the soil microbiome and ensures that specific bacterial-driven ecosystem functions recover after rewetting. This may provide the basis for more sustainable agricultural practices to counterbalance negative climate change-induced effects on soil functioning.

Visualization of pulmonary vein reconnections using dynamic mapping in redo procedures for patients with atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Pulmonary vein (PV) reconnection is commonly associated with recurrence of atrial fibrillation (AF) after the initial catheter ablation procedure. Visualization and identification of PV reconnections are critical during repeat procedures.

Purpose

To examine the use of dynamic mapping (LiveView) in combination with a high-density mapping catheter (HD Grid) in the recognition of PV reconnections in redo AF ablation procedures.

Methods

Acute procedure data from 81 patients were prospectively collected. Mapping catheter selection and the use of LiveView was determined at the physician’s discretion. For cases where LiveView was used, the location and number of gaps from the previous procedure were identified using both standard mapping and dynamic mapping separately.

Results

Most of the patients included in the analysis were treated for paroxysmal AF (PAF: n=63/81, 77.8%). Dynamic mapping data was incorporated in 50 PAF cases and 15 persistent AF cases. Within these 65 cases, standard mapping identified a total of 120 PV gaps whereas LiveView identified a total of 138 PV gaps; gaps were most frequently identified on the right PVs, especially in the anterior region (Table1). A contact force-sensing ablation catheter was commonly (n=64/81, 79%) used by the operators. The right anterior region was ablated with an average contact force of 13.8±3.1g and Lesion index (LSI) of 5.2±0.7 at a power of 35.8±8.4W. Non-PV ablation was performed in 38 (46.9%) patients; the most common lesion sets were roofline, cavotricuspid isthmus (CTI) line, and mitral isthmus line. Acute PV isolation was achieved in all patients at the end of the procedure.

Conclusion

Data from this analysis suggest the incorporation of dynamic mapping data may help reveal more PV reconnections compared to standard mapping. Additional study is needed to assess the long-term clinical outcomes when regional dynamic mapping data is used to identify PV reconnections in repeat procedures.

Bactericidal efficacy of low concentration of vaporized hydrogen peroxide with validation in a BSL-3 laboratory

BACKGROUND

Highly infective pathogens are cultured and studied in biosafety laboratories. It is critical to thoroughly disinfect these laboratories to prevent laboratory infection. A whole-room, non-contact, reduced corrosion disinfection strategy using hydrogen peroxide was proposed and evaluated.

AIM

To evaluate the bactericidal efficacy of 8% and 10% vaporized hydrogen peroxide( VHP) in a laboratory setting with spores and bacteria as bioindicators.

METHODS

Spores of B. atrophaeus and B. stearothermophilus, along with bacteria E. coli, S. aureus, and S. epidermidis were placed in pre-selected locations in a sealed laboratory and an OXY-PHARM NOCOSPRAY2 vaporized hydrogen peroxide generator was applied. Spore killing efficacy was qualitatively evaluated, and bactericidal efficacy was quantitatively analyzed, and the mean log10 reduction was determined. Finally, the optimized disinfection strategy was verified in a BSL-3 laboratory.

FINDINGS

Significant reductions in microbial load were obtained for each of the selected spores and bacteria when exposed to VHP in concentrations of 8% and 10% for 2～3 h. S. aureus was found to be more resistant than E. coli and S. epidermidis. Tests with 8% hydrogen peroxide and exposure for more than 3 h completely killed B. atrophaeus on surfaces and equipment in the BSL-3 laboratory.

CONCLUSION

The vaporized hydrogen peroxide generator is superior in terms of good diffusivity and low corrosiveness and is time-effective in removing the disinfectant residue. This study provides reference for the precise disinfection of air and object surfaces in biosafety laboratories under varying conditions.

Equine chorionic gonadotropin pretreatment 15 days before fixed-time artificial insemination improves the reproductive performance of replacement gilts

Fixed-time artificial insemination (FTAI) technology uses exogenous reproductive hormones to regulate the sexual cycle and ovulation of sows without oestrus identification, which improves the sow breeding utilisation rate, reduces the number of non-productive days, and elevates the efficiency of pig farm management. In this study, we aimed to optimise FTAI procedures. Healthy 190-day-old and about 90 kg Large White × Landrace crossing breed replacement gilts (n = 166) which were of unknown reproductive status were randomly selected and divided into three groups: a control group (n = 62), an eCG-15D group in which the gilts were pretreated with equine chorionic gonadotropin (eCG) injection 15 days before starting FTAI (n = 50), and an eCG-20D group pretreated with eCG injection 20 days before starting FTAI (n = 54). All three groups were then subjected to the same conventional FTAI procedure. Pigs were orally administered Altrenogest (ALT, 20 mg per pig per day) for 18 days and then 42 h after ALT feeding was stopped, they were injected with 1 000 IU eCG followed by 100 μg GnRH 80 h later. The gilts were inseminated for the first time 24 h after gonadotropin-releasing hormone (GnRH) injection and then again 16 h later. After 42 h of ALT feeding, gilts in the eCG-15D group displayed a higher follicular diameter until artificial insemination (AI) than those from the other groups (P < 0.05). In addition, the ovulation times were the most synchronised in the eCG-15D group, with 100% of the gilts ovulating before the second AI on day 25 of FTAI. Furthermore, the gilts in the eCG-15D group achieved the highest pregnancy rate (92%), farrowing rate (90%), total pigs born (11.59), and pigs born alive (11.18). Together, the findings of this study demonstrate that reproductive performance can be optimised by pretreating gilts with eCG 15 days before conventional FTAI.

Global upper-atmospheric heating on Jupiter by the polar aurorae

Jupiter's upper atmosphere is considerably hotter than expected from the amount of sunlight that it receives1-3. Processes that couple the magnetosphere to the atmosphere give rise to intense auroral emissions and enormous deposition of energy in the magnetic polar regions, so it has been presumed that redistribution of this energy could heat the rest of the planet4-6. Instead, most thermospheric global circulation models demonstrate that auroral energy is trapped at high latitudes by the strong winds on this rapidly rotating planet3,5,7-10. Consequently, other possible heat sources have continued to be studied, such as heating by gravity waves and acoustic waves emanating from the lower atmosphere2,11-13. Each mechanism would imprint a unique signature on the global Jovian temperature gradients, thus revealing the dominant heat source, but a lack of planet-wide, high-resolution data has meant that these gradients have not been determined. Here we report infrared spectroscopy of Jupiter with a spatial resolution of 2 degrees in longitude and latitude, extending from pole to equator. We find that temperatures decrease steadily from the auroral polar regions to the equator. Furthermore, during a period of enhanced activity possibly driven by a solar wind compression, a high-temperature planetary-scale structure was observed that may be propagating from the aurora. These observations indicate that Jupiter's upper atmosphere is predominantly heated by the redistribution of auroral energy.

Comparison of geographic workflow preferences with real-time dynamic regional mapping data during catheter ablation

Funding Acknowledgements

Type of funding sources: None.

Introduction

The clinical benefit of multielectrode high-density (HD) mapping during catheter ablation has been an area of active research. One advantage of HD mapping is improved sensitivity which can lead to better visualization and substrate delineation during the procedure. In addition to the advantages offered by the multielectrode grid mapping catheter (HD Grid), a novel software enable the display of beat-to-beat, dynamic regional mapping data from the current location of HD Grid in real-time (LiveView). The optimal settings and workflows to incorporate the dynamic data into routine ablation procedures have not been explored.

Purpose

To examine the common settings and workflow patterns among operators from different geographies when using dynamic mapping.

Methods

Observational procedural data including procedure time, total RF time, workflow preference, and fluoroscopy time, were prospectively collected from operators across Europe, the U.S., and Asia Pacific countries from May to September 2020. Cases from both catheter ablation of atrial and ventricular arrhythmias were included in the analysis.

Results

A total of 754 cases were collected (428, 133, and 193 cases from Europe, the U.S., and the Asia Pacific region, respectively). The most commonly reported indication across all three geographies was de novo paroxysmal atrial fibrillation (223/754, 30.0%). A steerable sheath was more frequently used with the mapping catheter in Europe and U.S. compared to Asia Pacific countries. Contrary to cases from the U.S. and Asia Pacific countries where the double transseptal approach was the preferred technique for left atrial procedures (78.8% and 55.3%, respectively), the single transseptal approach was more commonly observed in European cases (233/428, 54.4%). Visualization of real-time mapping data after creation of traditional full-chamber maps were commonly observed in all three geographies. Regardless of geography, the CS catheter was commonly used a reference electrode; and the most common map appearance settings for interior projection, exterior projection, and interpolation was 7, 7, and 7 respectively. Voltage cutoff of 0.1 mV, range from 0.01 to 1.5 mV, was most frequently observed for delineating scar in atrial arrhythmia cases analyzed in this dataset.

Conclusions

While there is a geographical difference in ablation workflow, common settings and patterns can be observed in all three regions. This data suggests that minimal workflow changes are required to incorporate the use of dynamic data into routine procedures. Adaptation of LiveView can help improve procedure efficiency and efficacy by reducing the need for full chamber maps, identifying areas that were under ablated, and confirming ablation endpoints. Further control study examining procedure efficiency and efficacy associated with dynamic mapping may be warranted.

Workflows and clinical utilization of dynamic mapping data in radiofrequency catheter ablation of cardiac arrhythmias

Funding Acknowledgements

Type of funding sources: None.

Introduction

Previous publications suggest that the use of high-density (HD) mapping leads to better substrate visualization and may lead to improved procedural outcomes. A novel dynamic mapping software, utilizes the HD grid mapping catheter (HD Grid) to display beat-to-beat, dynamic regional mapping data (LiveView). Incorporation of real-time dynamic mapping data into routine mapping/ablation workflows may further enhance the clinical benefits of HD mapping during radiofrequency (RF) catheter ablation procedures.

Purpose

 To examine the clinical utility and common workflows when dynamic mapping data was used during RF ablation procedures among operators with various experience levels.

Methods

Observational procedural data including procedure time, total RF time, and workflow preference were prospectively collected in catheter ablation cases utilizing LiveView from May to September 2020. Mapping and ablation strategies were determined at the operator’s discretion. Total percentage exceed 100% when multiple usage were reported.

Results

A total of 428 cases were collected from over 25 operators in 11 European countries. LiveView was used in a variety of cases including atrial fibrillation (paroxysmal and persistent), atrial flutter (typical and atypical), and VT (ischemic, non-ischemic, and idiopathic). Visualization of real-time mapping data from the current location of the HD Grid was commonly used after creation of traditional full-chamber maps (319/428, 74.5%). While operators in over 55% of the cases indicated that the use of dynamic display during mapping helped identify areas that were under ablated (238/428, 55.6%), using LiveView did not affect the lesion delivery strategies in those regions. LiveView was also used as a primary method for confirmation of pulmonary vein isolation (PVI) in 213 cases (49.8%). The most common reported usage of LiveView among the 428 cases analyzed was PVI confirmation/gap identification (75.2%), ablation line gap identification (41.1)%, and identification of breakthrough activation (23.6%)

Conclusions

This initial analysis demonstrated the diverse clinical utilization of LiveView dynamic display during RF catheter ablation procedures, including atrial and ventricular arrhythmias. Without causing significant changes to normal workflow, dynamic display of regional signals allows for rapid identification of ablation targets. When used during RF delivery, real-time assessment of regional activation patterns helped improve outcomes by rapidly identifying critical ablation location and ensuring successful lesion delivery. A further study that examines the impact of dynamic display on procedure efficacy may be warranted.

European early experience with a novel 3D mapping system

Funding Acknowledgements

Type of funding sources: None.

Introduction

Catheter navigation and 3-dimensional (3D) cardiac mapping are critical for successful electrophysiological ablation procedures. A novel 3D mapping system received CE Mark in July 2020. The system offers two imaging modalities: magnetic-based (VoXel) and impedance-based (NavX). Real-time display of 3D location and catheter movements is achieved via a magnetic field frame and magnetic sensors with supplemental impedance data when operating in VoXel mode or primarily via an impedance field generated from surface electrodes in NavX mode. To address limitations in data collection commonly experienced during 3D mapping, a new respiratory compensation algorithm, patient movement detection module, and metal compensation algorithm have been developed to enable consistent data collection throughout the full respiratory cycle even in challenging cases and lab environments.

Purpose

To examine the clinical utility and procedural characteristics associated with the use of this novel 3D mapping system among participating centers.

Methods

Procedural data was collected in cases utilizing the newly cleared mapping system during the initial evaluation phase in Europe. Procedural characteristics recorded included indication for mapping and ablation, rhythm mapped, chambers mapped, and procedure time.

Results

Procedural data was collected from over 250 cases across 12 European centers. A total of 12 indications for mapping and ablation were represented including de novo and redo atrial fibrillation (paroxysmal, persistent, long-standing persistent), ventricular tachycardia (ischemic, non-ischemic) or premature ventricular contraction, and supraventricular arrhythmias (typical and atypical atrial flutter, atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia). Over 70% of the cases were performed in VoXel mode. Impedance mode was mostly used in SVT cases or when the case was intended to be completed with minimal fluoroscopy. The most commonly mapped rhythms were sinus rhythm during voltage mapping and atrial tachycardia. The majority of cases (over 65%) were completed under conscious sedation; general anesthesia was used in 20% of the cases (15% not reported). The respiratory compensation algorithm was utilized in over 90% of the cases. For cases in which pre-procedural computed tomography or magnetic resonance imaging were available, operators indicated that the model shape was accurate when compared to pre-procedural imaging in 96% of the cases performed in VoXel mode.

Conclusions

Initial European experience with this novel 3D mapping system included a wide variety of arrhythmias in the atria and ventricles. This new mapping system offered operators the flexibility to tailor to specific procedure needs with two imaging modalities which were both widely utilized.

Patterns of fungal community succession triggered by C/N ratios during composting

Accumulating evidence indicates that the functional rather than taxonomic composition of microbial communities is closely correlated to local environmental factors. While composting is a widely accepted practice, specific knowledge of how fungal functional groups interact during the composting process remains limited. To address this, the impact of the initial C/N ratio of composting material on fungal community was analyzed in order to reveal the succession of functional diversity. Compared with the raw materials, the final composting product significantly reduced the relative abundances of plant and animal pathogens. Abundances of plant and animal pathogens, as well as dung saprotrophs, were negatively correlated with compost maturity, while abundances of wood saprotrophs exhibited positive correlations. Specific OTUs that showing highly abundant in each treatment were expected to compete for environmental preferences (niches) and/or interact with each other in positive (facilitative) ways. OTU2 (wood saprotroph) exhibiting the highest occurrence was negatively related to OTU7 (animal pathogen) and OTU4 (plant pathogen) during the mesophilic phase. Taken together, high-efficiency composting is represented as pattern variations of fungal community with a process of gradual decline of plant and animal pathogens as well as dung saprotrophs.

A Correlation Analysis between the Nutritional Status and Prognosis of COVID-19 Patients

PURPOSE

The present study investigated the correlation between the nutritional status and prognosis of COVID-19 patients, and analyzed the epidemiological characteristics of COVID-19 patients with different nutritional status.

METHODS

429 patients who were diagnosed positive for COVID-19 in Hubei Provincial Hospital of Traditional Chinese Medicine from December 2019 to March 2020 were selected and divided into different groups based on Controlling Nutritional Status (CONUT) score (0-4: the low CONUT score group; 5-12: the high CONUT score group). Multivariate logistic regression analysis was applied to investigate the effects of CONUT score on prognosis.

RESULTS

The total score of admission status of patients with higher CONUT score was higher than that of those with lower CONUT score (χ2 = 7.152, P = 0.007). The number of adverse outcomes of female was higher than that of male (χ2 = 10.253, P = 0.001). The number of adverse outcomes was higher for patients with smoking history (P = 0.004) or hypertension (χ2 = 11.240, P = 0.001) than those without. Also, the number of adverse outcomes was higher for older patients than younger ones (χ2 = 15.681, P < 0.001). Patients with adverse outcomes had lower urine red blood cell count than patients without adverse outcomes (χ2 = 5.029, P = 0.025). However, BMI, drinking history and diabetes did not show correlation with the prognosis of COVID-19 (P > 0.05).Among patients ≥ 61 years old, the risk of adverse outcomes in the high CONUT score group was 6.191 times that of the low CONUT score group (OR = 6.191, 95% CI: 1.431-26.785).Among the non-diabetic patients, the risk of adverse outcomes in the high CONUT group was 11.678 times that of the low CONUT group (OR = 11.678, 95% CI: 2.754-49.41).For the patients who had a total score of admission status < 6, the risk of adverse outcomes in the high CONUT score group was 8.216 times that of the low CONUT score group (OR = 8.216, 95% CI: 2.439-27.682).

CONCLUSION

COVID-19 patients with good nutritional status showed a small chance to have adverse outcomes. Gender, age, hypertension, the number of urine red blood cell count and CONUT score affected the adverse outcomes of patients.

Heat stress during late gestation disrupts maternal microbial transmission with altered offspring's gut microbial colonization and serum metabolites in a pig model

Heat stress (HS) during gestation has been associated with negative outcomes, such as preterm birth or postnatal metabolic syndromes. The intestinal microbiota is a unique ecosystem playing an essential role in mediating the metabolism and health of mammals. Here we hypothesize late gestational HS alters maternal microbial transmission and structures offspring's intestinal microbiota and serum metabolic profiles. Our results show maternal HS alters bacterial β-diversity and composition in sows and their piglets. In the maternal intestine, genera Ruminococcaceae UCG-005, [Eubacterium] coprostanoligenes group and Halomonas are higher by HS (q < 0.05), whereas the populations of Streptococcus, Bacteroidales RF16 group_norank and Roseburia are decreased (q < 0.05). In the maternal vagina, HS mainly elevates the proportions of phylum Bacteroidetes and Fusobacteria (q < 0.05), whereas reduces the population of Clostridiales Family XI (q < 0.05). In the neonatal intestine, maternal HS promotes the population of Proteobacteria but reduces the relative abundance of Firmicutes (q < 0.05). Moreover, the core Operational taxonomic units (OTU) analysis indicates the proportions of Clostridium sensu stricto 1, Romboutsia and Turicibacter are decreased by maternal HS in the intestinal and vaginal co-transmission, whereas that of phylum Proteobacteria and Epsilonbacteraeota, such as Escherichia-Shigella, Klebsiella, Acinetobacter, and Comamonas are increased in both the intestinal and vaginal co-transmission and the vagina. Additionally, Aeromonas is the only genus that is transmitted from environmental sources. Lastly, we evaluate the importance of neonatal differential OTU for the differential serum metabolites. The results indicate Acinetobacter significantly contributes to the differences in the adrenocorticotropic hormone (ACTH) and glucose levels due to HS (P < 0.05). Further, Stenotrophomonas is the most important variable for Cholesterol, low-density lipoprotein (LDL), diamine oxidase (DAO), blood urea nitrogen (BUN) and 5-hydroxytryptamine (5-HT) (P < 0.10). Overall, our data provides evidence for the maternal HS in establishing the neonatal microbiota via affecting maternal transmission, which in turn affects the maintenance of metabolic health.

Bio-organic fertilizers stimulate indigenous soil Pseudomonas populations to enhance plant disease suppression

BACKGROUND

Plant diseases caused by fungal pathogen result in a substantial economic impact on the global food and fruit industry. Application of organic fertilizers supplemented with biocontrol microorganisms (i.e. bioorganic fertilizers) has been shown to improve resistance against plant pathogens at least in part due to impacts on the structure and function of the resident soil microbiome. However, it remains unclear whether such improvements are driven by the specific action of microbial inoculants, microbial populations naturally resident to the organic fertilizer or the physical-chemical properties of the compost substrate. The aim of this study was to seek the ecological mechanisms involved in the disease suppressive activity of bio-organic fertilizers.

RESULTS

To disentangle the mechanism of bio-organic fertilizer action, we conducted an experiment tracking Fusarium wilt disease of banana and changes in soil microbial communities over three growth seasons in response to the following four treatments: bio-organic fertilizer (containing Bacillus amyloliquefaciens W19), organic fertilizer, sterilized organic fertilizer and sterilized organic fertilizer supplemented with B. amyloliquefaciens W19. We found that sterilized bioorganic fertilizer to which Bacillus was re-inoculated provided a similar degree of disease suppression as the non-sterilized bioorganic fertilizer across cropping seasons. We further observed that disease suppression in these treatments is linked to impacts on the resident soil microbial communities, specifically by leading to increases in specific Pseudomonas spp.. Observed correlations between Bacillus amendment and indigenous Pseudomonas spp. that might underlie pathogen suppression were further studied in laboratory and pot experiments. These studies revealed that specific bacterial taxa synergistically increase biofilm formation and likely acted as a plant-beneficial consortium against the pathogen.

CONCLUSION

Together we demonstrate that the action of bioorganic fertilizer is a product of the biocontrol inoculum within the organic amendment and its impact on the resident soil microbiome. This knowledge should help in the design of more efficient biofertilizers designed to promote soil function. Video Abstract.

Effects of the prebiotic inulin-type fructans on post-antibiotic reconstitution of the gut microbiome

AIMS

Interventions using prebiotic inulin-type fructans (ITFs) are widely prescribed to modulate the gut microbiota composition and activity to promote health. However, the impacts of ITFs on post-antibiotic reconstitution of the gut microbiome remain incompletely understood. The aim of the present study was to investigate the effects of ITFs supplementation on intestinal inflammation, the composition of the intestinal microbiota and the colonic transcriptome after antibiotic treatment.

METHODS AND RESULTS

Male BALB/c mice were subjected to an antibiotic cocktail (ABx) treatment for 7 days, and their microbiomes were then reconstituted either spontaneously or with ITFs supplementation (5%) for 14 days. Our data showed that ITFs supplementation delayed the recovery of antibiotic-induced colitis compared with the spontaneous recovery. Neither ITFs supplementation nor spontaneous recovery could restore the microbial community composition at the genus level back to its initial composition. ITFs supplementation increased the relative abundance of some beneficial bacteria and butyrate levels, but resulted in selective blooms of some opportunistic pathogens and elevated the pathways associated with diseases linked to gut microbiota function. Both ITFs supplementation and spontaneous recovery could restore the colonic transcriptome nearly to the initial profile to a certain extent; however, ITFs supplementation delayed the restoration of the immunoglobulin genes compared to spontaneous recovery.

CONCLUSION

These data showed that post-antibiotic ITFs consumption did not always lead to beneficial effects but might lead to potential adverse effects in the context of dysbiosis.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings highlighted that caution is required when supplementing ITFs to restore intestinal homeostasis in the context of dysbiosis resulting from broad-spectrum antibiotics.

P1383Procedural differences during de novo paroxysmal atrial fibrillation ablation with a contact force-sensing ablation catheter between Europe and U.S

Background

Although pulmonary vein isolation (PVI) is considered the standard approach of atrial fibrillation ablation worldwide, procedural practice during the ablation varies by geographical region. Using the same magnetic sensor enabled contact force-sensing ablation catheter for the treatment of de novo paroxysmal atrial fibrillation, a comparison of procedural detail between Europe and U.S operators can provide insights into geographic specific clinical practices. 

Purpose

To characterize and compare procedural differences during paroxysmal atrial fibrillation ablation performed with a magnetic sensor enabled contact force-sensing catheter across European and U.S. centers. 

Methods

Procedural data were prospectively collected in clinical cases performed with a new magnetic sensor enabled, contact force ablation catheter within the first 6 months of use at participating centers in Europe and the U.S. Procedure time, PVI time, PVI confirmation method, fluoroscopy usage and lesion delivery parameters were analyzed based on geographies. 

Results

A total of 131 cases across 35 centers in 11 European countries, and 95 cases across 26 U.S. centers were analyzed. Target geometry was created with the ablation catheter in 94 out of 131 (71.8%) European cases, while only 5 out of 95 U.S. cases (5.3%) reported the use of the ablation catheter for model creation. Although a steerable sheath (64.1% and 67.3%) was commonly used with the ablation catheter in both geographies, difference in the utilization of bidirectional contact force catheter (52.7% and 90.5%) and the automated lesion marking module (76.3% and 81.1%) were observed in European and U.S. cases, respectively. The use of adenosine or isoproterenol to confirm PVI was reported in 25% and 64% of the European and U.S. cases. Average waiting periods were 18.2 minutes and 26.5 minutes from reported European and U.S. cases. Total procedural time, mapping time, and fluoroscopy time were similar between European and U.S. cases. (Table). First pass PVI were 66.4% and 72.6% for European and U.S. cases, respectively.

Conclusion

Total procedural time and RF time were similar between European and U.S. cases during de novo paroxysmal atrial fibrillation ablation using the same ablation catheter. Differences in workflow including the use of a mapping catheter for geometry creation and waiting period were observed between the two geographies.

Summary of procedural details De novo PAF N Procedural time(min) Mapping time (min) PVI time (min) Total RF time (min) Fluoro time( min) Europe 131 144.0 ± 56.9 16.6 ± 17.1 69.8 ± 35.0 33.2 ± 15.6 11.6 ± 10.1 U.S. 95 137.6 ± 64.8 18.1 ± 23.5 58.8 ± 31.5 32.3 ± 22.2 12.0 ± 15.8

P981Comparison of automark utilization and lesion metric target during paroxysmal atrial fibrillation ablation with a contact force-sensing ablation catheter: European and U.S. multicenter Experiences

Background

Accurate delivery of transmural lesion is associated with improved durability of pulmonary vein isolation and reduced reconduction. Lesion quality depends on multiple parameters such as radiofrequency power, tissue-catheter contact, duration of energy application, and catheter tip temperature. Consequently, energy delivery parameters vary based on individual operators’ preferences and procedural needs.

Purpose

To characterize and compare the utilization of automated lesion marking feature and lesion delivery parameters used during paroxysmal atrial fibrillation ablation performed with a magnetic sensor enabled contact force-sensing catheter across European and U.S. centers.

Methods

Procedural data were prospectively collected in clinical cases performed with a new magnetic sensor enabled, contact force ablation catheter within the first 6 months of use at participating centers in Europe and the U.S. Use of bidirectional CF catheters, steerable sheaths, automated lesion marking software and associated lesion delivery parameters during paroxysmal atrial fibrillation ablation were evaluated.

Results

A total of 149 cases across 37 centers in 11 European countries, and 112 cases across 31 U.S. centers were analyzed. A bidirectional contact force catheter (56.4% and 90.2%), a steerable sheath (65.8% and 69.6%), and the automated lesion marking module (77.9% and 90.2%) were used in most European and U.S. cases, respectively. The most commonly reported energy delivery parameters were: lesion index (LSI), Force-Time Integral (FTI), and time from European cases; LSI, average force, and FTI for U.S. cases (Table). Target LSI values were recorded for 126 cases in Europe and 34 in the U.S, ranging from 3 to 6. In anterior/roof segments, most common LSI target values for anterior/roof and posterior/inferior segments were 6 (42.9%) and 5 (51.2%) in Europe, and 5.5 (44.1%) and 5 (54.5%) in the U.S. PVI was confirmed with an average of 20.3 minutes waiting period (69.1%) for European cases and exit block (57.1%) in U.S. cases. First pass PVI were 67.1% and 74.4% for European and U.S. cases, respectively.

Conclusion

Energy delivery parameters and PVI confirmation method varied considerably by geography during paroxysmal atrial fibrillation ablation using the magnetic sensor enabled, contact force ablation catheter. Further study on efficacy implication on these differences in practice should be examined.

Energy delivery parameters used Paroxysmal AF N LSI FTI Time Imp Drop Avg Force Other N/A Europe 149 44.0 % 13.4 % 7.0 % 6.0 % 2.4 % 1.0 % 26.2 % U.S. 112 31.2% 17.9 % 6.2 % 8.0 % 23.2 % 11.7 % 1.8 % Energy delivery parameters used in paroxysmal AF ablation in Europe and U.S.

The H3+ ionosphere of Uranus: decades-long cooling and local-time morphology

The upper atmosphere of Uranus has been observed to be slowly cooling between 1993 and 2011. New analysis of near-infrared observations of emission from H3+ obtained between 2012 and 2018 reveals that this cooling trend has continued, showing that the upper atmosphere has cooled for 27 years, longer than the length of a nominal season of 21 years. The new observations have offered greater spatial resolution and higher sensitivity than previous ones, enabling the characterization of the H3+ intensity as a function of local time. These profiles peak between 13 and 15 h local time, later than models suggest. The NASA Infrared Telescope Facility iSHELL instrument also provides the detection of a bright H3+ signal on 16 October 2016, rotating into view from the dawn sector. This feature is consistent with an auroral signal, but is the only of its kind present in this comprehensive dataset. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H3+, H5+ and beyond'.

Lime and ammonium carbonate fumigation coupled with bio-organic fertilizer application steered banana rhizosphere to assemble a unique microbiome against Panama disease

Microbiome plays a key role in determining soil suppressiveness against invading pathogens. Our previous study revealed that microbial community of bulk soil could be manipulated by lime and ammonium bicarbonate fumigation followed by biofertilizer application. However, the assembly of microbial community suppressive to banana Panama disease in the rhizosphere is still unclear. In this study, we used high-throughput sequencing and quantitative PCR to explore the assembly of rhizosphere microbiome associated with banana Panama disease suppression in a two-seasonal pot experiment. We found biofertilizer applied to lime and ammonium bicarbonate fumigated soil significantly (P < 0.05) reduced the abundance of rhizosphere Fusarium oxysporum compared to biofertilizer applied to non-fumigated soil. Principal coordinate analysis revealed that biofertilizer applied to lime and ammonium bicarbonate fumigated soil re-shaped the rhizosphere bacterial community composition by increasing the phylogenetic relatedness, and stimulating indigenous microbes, for example, Gemmatimonas, Sphingomonas, Pseudomonas, Lysobacter and Bacillus. Co-occurrence analysis revealed that potential species involved in disease suppression were more interrelated in disease-suppressive soils. Taken together, lime and ammonium bicarbonate fumigation followed by biofertilizer application could induce banana rhizosphere to assemble beneficial microbes dominated consortia to suppress banana Panama disease.

Antimicrobial activity and toxicity of gold nanoparticles: research progress, challenges and prospects

Gold nanoparticles are emerging materials that exhibit characteristics distinct from those of traditional materials and that have promising potential for application in the fields of chemistry, physics, biology and medicine. During the past decades, numerous studies on the antimicrobial activity and toxicity of gold nanoparticles have been published. With respect to antimicrobial activity, gold nanoparticles conjugated with small molecules, such as antibiotics, drugs, vaccines and antibodies, are more efficient than individual nanoparticles and molecules. Regarding the toxicity effects, results are often unclear and conflicting because of the lack of a standard experimental method; various studies have used different approaches, administration routes and doses, and similar experiments may lead to different conclusions. To provide a systematic overview of and insight in the current knowledge for researchers committed to this filed, we discuss the recent research advances related to the antimicrobial activity and toxicity of gold nanoparticles, both in vitro and in vivo, and identify major issues that require further study. SIGNIFICANCE AND IMPACT OF THE STUDY: This paper discusses the recent research progress on antimicrobial activity and toxicity of gold nanoparticles and provides general insights into the field for researchers committed to this field.

Isolation of Antagonistic Endophytes from Banana Roots against Meloidogyne javanica and Their Effects on Soil Nematode Community

Banana production is seriously hindered by Meloidogyne spp. all over the world. Endophytes are ideal candidates compared to pesticides as an environmentally benign agent. In the present study, endophytes isolated from banana roots infected by Meloidogyne spp. with different disease levels were tested in vitro, and in sterile and nature banana monoculture soils against Meloidogyne javanica. The proportion of antagonistic endophytes were higher in the roots of middle and high disease levels. Among those, bacteria were dominant, and Pseudomonas spp., Bacillus spp. and Streptomyces spp. showed more abundant populations. One strain, named as SA, with definite root inner-colonization ability was isolated and identified as Streptomyces sp. This strain showed an inhibiting rate of >50% in vitro and biocontrol efficiency of 70.7% in sterile soil against Meloidogyne javanica, compared to the control. Greenhouse experiment results showed that the strain SA exhibits excellent biological control ability for plant-parasites both in roots and in root-knot nematode infested soil. SA treatment showed a higher number of bacterivores, especially Mesorhabditis and Cephalobus. The maturity index was significantly lower, while enrichment index (EI) was significantly higher in the SA treatment. In conclusion, this study presents an important potential application of the endophytic strain Streptomyces sp. for the control of plant-parasitic nematodes, especially Meloidogyne javanica, and presents the effects on the associated variation of the nematode community.

Managing interoperability and complexity in health systems

In recent years, we have witnessed substantial progress in the use of clinical informatics systems to support clinicians during episodes of care, manage specialised domain knowledge, perform complex clinical data analysis and improve the management of health organisations' resources. However, the vision of fully integrated health information eco-systems, which provide relevant information and useful knowledge at the point-of-care, remains elusive. This journal Focus Theme reviews some of the enduring challenges of interoperability and complexity in clinical informatics systems. Furthermore, a range of approaches are proposed in order to address, harness and resolve some of the many remaining issues towards a greater integration of health information systems and extraction of useful or new knowledge from heterogeneous electronic data repositories.

Continous application of bioorganic fertilizer induced resilient culturable bacteria community associated with banana Fusarium wilt suppression

Fusarium wilt of banana always drives farmers to find new land for banana cultivation due to the comeback of the disease after a few cropping years. A novel idea for solving this problem is the continuous application of bioorganic fertilizer (BIO), which should be practiced from the beginning of banana planting. In this study, BIO was applied in newly reclaimed fields to pre-control banana Fusarium wilt and the culturable rhizobacteria community were evaluated using Biolog Ecoplates and culture-dependent denaturing gradient gel electrophoresis (CD-DGGE). The results showed that BIO application significantly reduced disease incidences and increased crop yields, respectivly. And the stabilized general bacterial metabolic potential, especially for the utilization of carbohydrates, carboxylic acids and phenolic compounds, was induced by BIO application. DGGE profiles demonstrated that resilient community structure of culturable rhizobacteria with higher richness and diversity were observed in BIO treated soils. Morever, enriched culturable bacteria affiliated with Firmicutes, Gammaproteobacteria and Actinobacteria were also detected. In total, continuous application of BIO effectively suppressed Fusarium wilt disease by stabilizing culturable bacterial metabolic potential and community structure. This study revealed a new method to control Fusarium wilt of banana for long term banana cultivation.

14,15-epoxyeicosatrienoic acid promotes production of brain derived neurotrophic factor from astrocytes and exerts neuroprotective effects during ischaemic injury

AIMS

14,15-Epoxyeicosatrienoic acid (14,15-EET) is abundantly expressed in brain and exerts protective effects against ischaemia. 14,15-EET is hydrolysed by soluble epoxide hydrolase (sEH). sEH^-/- mice show a higher level of 14,15-EET in the brain. Astrocytes play a pivotal role in neuronal survival under ischaemic conditions. However, it is unclear whether the neuroprotective effect of 14,15-EET is associated with astrocytes.

METHODS

A mouse model of focal cerebral ischaemia was induced by middle cerebral artery occlusion. Oxygen-glucose deprivation/reoxygenation (OGD/R) was performed on cultured murine astrocytes, neurons and a human cell line. Cell viabilities were measured by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. The mRNA expressions were quantified by real-time PCR. Brain derived neurotrophic factor (BDNF) concentration was measured by ELISA. Protein expressions were quantified by Western blotting. BDNF and peroxisome proliferators-activated receptor gamma (PPAR-γ) expressions were analysed by confocal microscopy.

RESULTS

Decreased infarct volumes, elevated BDNF expression and increased numbers of BDNF/GFAP Glial Fibrillary Acidic Protein double-positive cells were observed in the ischaemic penumbra of sEH^-/- mice. The decreased infarct volumes of sEH^-/- mice were diminished by intracerebroventricular injection of a blocker of BDNF receptor. 14,15-EET increases BDNF expression and cell viability of murine astrocytes and U251 cells by BDNF-TrkB Tyrosine receptor kinase-B-extracellular signal-regulated kinase 1/2 signalling during OGD/R. 14,15-EET protects neurons from OGD/R by stimulating the production of astrocyte-derived BDNF. 14,15-EET stimulates the production of astrocyte-derived BDNF through PPAR-γ/p-cAMP-response element binding protein signal pathways.

CONCLUSIONS

Our study demonstrates the importance of 14,15-EET-mediated production of astrocyte-derived BDNF for enhancing viability of astrocytes and protecting neurons from the ischaemic injury and provides insights into the mechanism by which 14,15-EET is involved in neuroprotection.

Single nucleotide polymorphism in the neuroplastin locus associates with cortical thickness and intellectual ability in adolescents

Despite the recognition that cortical thickness is heritable and correlates with intellectual ability in children and adolescents, the genes contributing to individual differences in these traits remain unknown. We conducted a large-scale association study in 1583 adolescents to identify genes affecting cortical thickness. Single-nucleotide polymorphisms (SNPs; n=54,837) within genes whose expression changed between stages of growth and differentiation of a human neural stem cell line were selected for association analyses with average cortical thickness. We identified a variant, rs7171755, associating with thinner cortex in the left hemisphere (P=1.12 × 10(-)(7)), particularly in the frontal and temporal lobes. Localized effects of this SNP on cortical thickness differently affected verbal and nonverbal intellectual abilities. The rs7171755 polymorphism acted in cis to affect expression in the human brain of the synaptic cell adhesion glycoprotein-encoding gene NPTN. We also found that cortical thickness and NPTN expression were on average higher in the right hemisphere, suggesting that asymmetric NPTN expression may render the left hemisphere more sensitive to the effects of NPTN mutations, accounting for the lateralized effect of rs7171755 found in our study. Altogether, our findings support a potential role for regional synaptic dysfunctions in forms of intellectual deficits.