Novel strategies for inhibition of bacterial biofilm in chronic rhinosinusitis

An important role has been recently reported for bacterial biofilm in the pathophysiology of chronic diseases, such as chronic rhinosinusitis (CRS). CRS, affecting sinonasal mucosa, is a persistent inflammatory condition with a high prevalence around the world. Although the exact pathological mechanism of this disease has not been elicited yet, biofilm formation is known to lead to a more significant symptom burden and major objective clinical indicators. The high prevalence of multidrug-resistant bacteria has severely restricted the application of antibiotics in recent years. Furthermore, systemic antibiotic therapy, on top of its insufficient concentration to eradicate bacteria in the sinonasal biofilm, often causes toxicity, antibiotic resistance, and an effect on the natural microbiota, in patients. Thus, coming up with alternative therapeutic options instead of systemic antibiotic therapy is emphasized in the treatment of bacterial biofilm in CRS patients. The use of topical antibiotic therapy and antibiotic eluting sinus stents that induce higher antibiotic concentration, and decrease side effects could be helpful. Besides, recent research recognized that various natural products, nitric oxide, and bacteriophage therapy, in addition to the hindered biofilm formation, could degrade the established bacterial biofilm. However, despite these improvements, new antibacterial agents and CRS biofilm interactions are complicated and need extensive research. Finally, most studies were performed in vitro, and more preclinical animal models and human studies are required to confirm the collected data. The present review is specifically discussing potential therapeutic strategies for the treatment of bacterial biofilm in CRS patients.     

Coupled Single-Cell CRISPR Screening and Epigenomic Profiling Reveals Causal Gene Regulatory Networks

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Construction of novel single-cell screening system using a yeast cell chip for nano-sized modified-protein-displaying libraries

A novel screening system using a microchamber array chip was developed for construction of combinatorial nano-sized protein libraries in combination with yeast cell surface engineering. It is possible to place a single yeast cell into each microchamber, to observe its behavior, and to pick up the target cell. The microchamber array chip is referred to as a “yeast cell chip.” A single EGFP-displaying yeast cell could be detected, picked up by a micro-manipulator, and cultivated on agar medium. Furthermore, a catalytic reaction, the hydrolysis of fluorescein dioctanate, by a single yeast cell displaying Rhizopus oryzae lipase (ROL) was carried out in one microchamber. The ROL-encoding gene in a single ROL-displaying cell was amplified by PCR. These results demonstrate that this yeast cell chip in combination with cell surface engineering could be used as a tool in a high-throughput screening system not only for a single living cell and a whole-cell catalyst with a nano-sized protein cluster but also for modified nano-sized and functional protein molecules from protein libraries on the cell surface.     

SIMULATED VESSEL APPROACHES ELICIT DIFFERENTIAL RESPONSES FROM MANATEES

One of the most pressing concerns associated with conservation of the endangered Florida manatee is mortality and serious injury due to collisions with watercraft. Watercraft collisions are the leading identified cause of manatee mortality, averaging 25% and reaching 31% of deaths each year. The successful establishment and management of protected areas depend upon the acquisition of data assessing how manatees use different habitats, and identification of environmental characteristics influencing manatee behavior and habitat selection. Acoustic playback experiments were conducted to assess the behavioral responses of manatees to watercraft approaches. Playback stimuli made from prerecorded watercraft approaches were constructed to simulate a vessel approach to approximately 10 m in sea grass habitats. Stimulus categories were (1) silent control, (2) approach with outboard at idle speed, (3) vessel approach at planning speed, and (4) fast personal watercraft approach. Analyses of swim speed, changes in behavioral state, and respiration rate indicate that the animals responded differentially to the playback categories. The most pronounced responses, relative to the controls, were elicited by personal watercraft. Quantitative documentation of response during playbacks provides data that may be used as the basis for future models to predict the impact of specific human activities on manatees and other marine mammal populations.     

我国蝗虫暴发成灾的现状及其持续控制对策

概述并分析了我国蝗虫暴发成灾的现状及原因 ,认为全球气候变暖和区域性气候异常、人类活动的影响、监测预警技术手段落后、成灾蝗种增多和发生为害类型复杂、蝗虫研究队伍锐减及基础理论与高新技术研究滞后导致了近年来蝗虫的暴发成灾。对此 ,作者从蝗虫灾害的规律性、监测预警高新技术和综合治理技术等方面提出了实现蝗灾可持续控制的对策     

Satellite remote sensing,biodiversity research and conservation of the future

Assessing and predicting ecosystem responses to global environmental change and its impacts on human well-being are high priority targets for the scientific community. The potential for synergies between remote sensing science and ecology, especially satellite remote sensing and conservation biology, has been highlighted by many in the past. Yet, the two research communities have only recently begun to coordinate their agendas. Such synchronization is the key to improving the potential for satellite data effectively to support future environmental management decision-making processes. With this themed issue, we aim to illustrate how integrating remote sensing into ecological research promotes a better understanding of the mechanisms shaping current changes in biodiversity patterns and improves conservation efforts. Added benefits include fostering innovation, generating new research directions in both disciplines and the development of new satellite remote sensing products.     

Digital imaging approaches for phenotyping whole plant nitrogen and phosphorus response in Bracbypodium distacbyon

This work evaluates the phenotypic response of the model grass （Brachypodium distacbyon （L.） P. Beauv.） to nitrogen and phosphorus nutrition using a combination of imaging techniques and destructive harvest of shoots and roots. Reference line Bd21-3 was grown in pots using 11 phosphorus and 11 nitrogen concentrations to establish a dose-response curve. Shoot biovolume and biomass, root length and biomass, and tissue phosphorus and nitrogen concentrations increased with nutrient concentration. Shoot biovolume, estimated by imaging, was highly correlated with dry weight （R2 〉 0.92） and both biovolume and growth rate responded strongly to nutrient availability. Higher nutrient supply increased nodal root length more than other root types. Photochemical efficiency was strongly reduced by low phosphorus concentrations as early as 1 week after germination, suggesting that this measurement may be suitable for high throughput screening of phosphorus response. In contrast, nitrogen concentration had little effect on photochemical efficiency. Changes in biovolume over time were used to compare growth rates of four accessions in response tonitrogen and phosphorus supply. We demonstrate that a time series image-based approach coupled with mathematical modeling provides higher resolution of genotypic response to nutrient supply than traditional destructive techniques and shows promise for high throughput screening and determina- tion of genomic regions associated with superior nutrient use efficiency.     

Genome sequencing of a single cell of the widely distributed marine subsurface Dehalococcoidia,phylum Chloroflexi

Bacteria of the class Dehalococcoidia (DEH), phylum Chloroflexi, are widely distributed in the marine subsurface, yet metabolic properties of the many uncultivated lineages are completely unknown. This study therefore analysed genomic content from a single DEH cell designated ‘DEH-J10'' obtained from the sediments of Aarhus Bay, Denmark. Real-time PCR showed the DEH-J10 phylotype was abundant in upper sediments but was absent below 160 cm below sea floor. A 1.44 Mbp assembly was obtained and was estimated to represent up to 60.8% of the full genome. The predicted genome is much larger than genomes of cultivated DEH and appears to confer metabolic versatility. Numerous genes encoding enzymes of core and auxiliary beta-oxidation pathways were identified, suggesting that this organism is capable of oxidising various fatty acids and/or structurally related substrates. Additional substrate versatility was indicated by genes, which may enable the bacterium to oxidise aromatic compounds. Genes encoding enzymes of the reductive acetyl-CoA pathway were identified, which may also enable the fixation of CO₂ or oxidation of organics completely to CO₂. Genes encoding a putative dimethylsulphoxide reductase were the only evidence for a respiratory terminal reductase. No evidence for reductive dehalogenase genes was found. Genetic evidence also suggests that the organism could synthesise ATP by converting acetyl-CoA to acetate by substrate-level phosphorylation. Other encoded enzymes putatively conferring marine adaptations such as salt tolerance and organo-sulphate sulfohydrolysis were identified. Together, these analyses provide the first insights into the potential metabolic traits that may enable members of the DEH to occupy an ecological niche in marine sediments.