Healing with precision: A multi-functional hydrogel-bioactive glass dressing boosts infected wound recovery and enhances neurogenesis in the wound bed.

Chronic skin wounds, especially infected ones, pose a significant clinical challenge due to their increasing incidence and poor outcomes. The deteriorative microenvironment in such wounds, characterized by reduced extracellular matrix, impaired angiogenesis, insufficient neurogenesis, and persistent bacterial infection, has prompted the exploration of novel therapeutic strategies. In this study, we developed an injectable multifunctional hydrogel (GEL/BG@Cu + Mg) incorporating Gelatin-Tannic acid/ N-hydroxysuccinimide functionalized polyethylene glycol and Bioactive glass doped with copper and magnesium ions to accelerate the healing of infected wounds. The GEL/BG@Cu + Mg hydrogel composite demonstrates good biocompatibility, degradability, and rapid formation of a protective barrier to stop bleeding. Synergistic bactericidal effects are achieved through the photothermal properties of BG@Cu + Mg and sustained copper ions release, with the latter further promoting angiogenesis. Furthermore, the hydrogel enhances neurogenesis by stimulating axons and Schwann cells in the wound bed through the beneficial effects of magnesium ions. Our results demonstrate that the designed novel multifunctional hydrogel holds tremendous promise for treating infected wounds and allowing regenerative neurogenesis at the wound site, which provides a viable alternative for further improving clinical outcomes.

Rice bacterial leaf blight drives rhizosphere microbial assembly and function adaptation.

IMPORTANCE: Our results suggest that rhizosphere bacteria are more sensitive to bacterial leaf blight (BLB) than fungi. BLB infection decreased the diversity of the rhizosphere bacterial community but increased the complexity and size of the rhizosphere microbial community co-occurrence networks. In addition, the relative abundance of the genera Streptomyces, Chitinophaga, Sphingomonas, and Bacillus increased significantly. Finally, these findings contribute to the understanding of plant-microbiome interactions by providing critical insight into the ecological mechanisms by which rhizosphere microbes respond to phyllosphere diseases. In addition, it also lays the foundation and provides data to support the use of plant microbes to promote plant health in sustainable agriculture, providing critical insight into ecological mechanisms.

Resistance of Xanthomonas oryzae pv. oryzae to Lytic Phage X2 by Spontaneous Mutation of Lipopolysaccharide Synthesis-Related Glycosyltransferase.

Phage therapy is a promising biocontrol management on plant diseases caused by bacterial pathogens due to its specificity, efficiency and environmental friendliness. The emergence of natural phage-resistant bacteria hinders the application of phage therapy. Xanthomonas oryzae pv. oryzae (Xoo) is the causal agent of the devastating bacterial leaf blight disease of rice. Here, we obtained a spontaneous mutant C2R of an Xoo strain C2 showing strong resistance to the lytic phage X2. Analysis of the C2R genome found that the CDS2289 gene encoding glycosyltransferase acquired a frameshift mutation at the 180th nucleotide site, which also leads to a premature stop mutation at the 142nd amino acid. This mutation confers the inhibition of phage adsorption through the changes in lipopolysaccharide production and structure and bacterial surface morphology. Interestingly, glycosyltransferase-deficient C2R and an insertional mutant k2289 also showed reduced virulence, suggesting the trade-off costs of phage resistance. In summary, this study highlights the role of glycosyltransferase in interactions among pathogenic bacteria, phages and plant hosts, which provide insights into balanced coevolution from environmental perspectives.

The Holin-Endolysin Lysis System of the OP2-Like Phage X2 Infecting Xanthomonas oryzae pv. oryzae.

Most endolysins of dsDNA phages are exported by a holin-dependent mechanism, while in some cases endolysins are exported via a holin-independent mechanism. However, it is still unclear whether the same endolysins can be exported by both holin-dependent and holin-independent mechanisms. This study investigated the lysis system of OP2-like phage X2 infecting Xanthomonas oryzae pv. oryzae, causing devastating bacterial leaf blight disease in rice. Based on bioinformatics and protein biochemistry methods, we show that phage X2 employs the classic "holin-endolysin" lysis system. The endolysin acts on the cell envelope and exhibits antibacterial effects in vitro, while the holin facilitates the release of the protein into the periplasm. We also characterized the role of the transmembrane domain (TMD) in the translocation of the endolysin across the inner membrane. We found that the TMD facilitated the translocation of the endolysin via the Sec secretion system. The holin increases the efficiency of protein release, leading to faster and more efficient lysis. Interestingly, in E. coli, the expression of either holin or endolysin with TMDs resulted in the formation of long rod shaped cells. We conclude that the TMD of X2-Lys plays a dual role: One is the transmembrane transport while the other is the inhibition of cell division, resulting in larger cells and thus in a higher number of released viruses per cell.

Epidemiological characteristics and trends of notifiable infectious diseases in China from 1986 to 2016.

BACKGROUND: Since the 1980s, China has undergone significant social change and the incidence of infectious diseases has also changed considerably. Here, we report the epidemiological features and changes in notifiable infectious diseases in China from 1986 to 2016 to explore the factors contributing to the successful control of infectious diseases and the challenges faced in the prevention and control of infectious diseases. METHODS: The data of notifiable infectious diseases in China from 1986 to 2016 were collected from the monthly analysis report of the National Infectious Disease Surveillance System. Joinpoint regression models were used to examine incidence and mortality trends from 1986 to 2016. IBM SPSS Statistics version 22.0, Excel 2010 and R x64 3.5.2 were used for data analysis. RESULTS: A total of 132 858 005 cases of notifiable infectious diseases were reported over these 31 years, with an average yearly incidence of 342.14/100 000. There were 284 694 deaths with an average yearly mortality rate of 0.73/100 000. The overall incidence and overall mortality of notifiable infectious diseases both showed a "U" distribution (ie, a decrease, stable, an increase, stable again). The top five diseases in terms of incidence were hand, foot and mouth disease, viral hepatitis, tuberculosis, other infectious causes of diarrhea and dysentery, accounting for 78.0% of all reported cases. The top five causes of death were HIV/AIDS, rabies, tuberculosis, viral hepatitis and epidemic encephalitis B, which accounted for 76.07% of all mortalities. The diseases with the top five fatality rates were rabies, H5N1, H7N9, HIV/AIDS and plague, with rates of 91.06%, 66.07%, 38.51%, 25.19% and 10.31%, respectively. CONCLUSIONS: This analysis will benefit the future monitoring of infectious diseases and public health measures in China.

Biosynthesis of Silver Nanoparticles Using Onion Endophytic Bacterium and Its Antifungal Activity against Rice Pathogen Magnaporthe oryzae.

Biosynthesis of silver nanoparticles (AgNPs) using endophytic bacteria is a safe alternative to the traditional chemical method. The purpose of this research is to biosynthesize AgNPs using endophytic bacterium Bacillus endophyticus strain H3 isolated from onion. The biosynthesized AgNPs with sizes from 4.17 to 26.9 nm were confirmed and characterized by various physicochemical techniques such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), UV-visible spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) in addition to an energy dispersive spectrum (EDS) profile. The biosynthesized AgNPs at a concentration of 40 µg/mL had a strong antifungal activity against rice blast pathogen Magnaporthe oryzae with an inhibition rate of 88% in mycelial diameter. Moreover, the biosynthesized AgNPs significantly inhibited spore germination and appressorium formation of M. oryzae. Additionally, microscopic observation showed that mycelia morphology was swollen and abnormal when dealing with AgNPs. Overall, the current study revealed that AgNPs could protect rice plants against fungal infections.

Bioinspired Green Synthesis of Chitosan and Zinc Oxide Nanoparticles with Strong Antibacterial Activity against Rice Pathogen Xanthomonas oryzae pv. oryzae.

Bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most devastating diseases, resulting in significant yield losses in rice. The extensive use of chemical antibacterial agents has led to an increase the environmental toxicity. Nanotechnology products are being developed as a promising alternative to control plant disease with low environmental impact. In the present study, we investigated the antibacterial activity of biosynthesized chitosan nanoparticles (CSNPs) and zinc oxide nanoparticles (ZnONPs) against rice pathogen Xoo. The formation of CSNPs and ZnONPs in the reaction mixture was confirmed by using UV-vis spectroscopy at 300-550 nm. Moreover, CSNPs and ZnONPs with strong antibacterial activity against Xoo were further characterized by scanning and transmission electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction. Compared with the corresponding chitosan and ZnO alone, CSNPs and ZnONPs showed greater inhibition in the growth of Xoo, which may be mainly attributed to the reduction in biofilm formation and swimming, cell membrane damage, reactive oxygen species production, and apoptosis of bacterial cells. Overall, this study revealed that the two biosynthesized nanoparticles, particularly CSNPs, are a promising alternative to control rice bacterial disease.

Biogenic Synthesis of Silver Nanoparticles Using Phyllanthus emblica Fruit Extract and Its Inhibitory Action Against the Pathogen Acidovorax oryzae Strain RS-2 of Rice Bacterial Brown Stripe.

Biogenic synthesis of silver nanoparticles (AgNPs) using plants has become a promising substitute to the conventional chemical synthesis method. In this study, we report low-cost, green synthesis of AgNPs using fresh fruit extract of Phyllanthus emblica. The biosynthesized AgNPs was confirmed and characterized by analysis of spectroscopy profile of the UV-visible and Energy dispersive spectrophotometer, Fourier transform infrared, X-ray diffraction pattern, and electron microscopy images examination. UV-visible spectra showed a surface resonance peak of 430 nm corresponding to the formation of AgNPs, and FTIR spectra confirmed the involvement of biological molecules in AgNPs synthesis. In spherical AgNPs, the particle size ranged from 19.8 to 92.8 nm and the average diameter was 39 nm. Synthesized nanoparticles at 20 µg/ml showed remarkable antimicrobial activity in vitro against the pathogen Acidovorax oryzae strain RS-2 of rice bacterial brown stripe, while 62.41% reduction in OD600 value was observed compared to the control. Moreover, the inhibitory efficiency of AgNPs increased with the increase of incubation time. Furthermore, AgNPs not only disturbed biofilm formation and swarming ability but also increased the secretion of effector Hcp in strain RS-2, resulting from damage to the cell membrane, which was substantiated by TEM images and live/dead cell staining result. Overall, this study suggested that AgNPs can be an attractive and eco-friendly candidate to control rice bacterial disease.

Enhanced transgene expression in rice following selection controlled by weak promoters.

BACKGROUND: Techniques that enable high levels of transgene expression in plants are attractive for the commercial production of plant-made recombinant pharmaceutical proteins or other gene transfer related strategies. The conventional way to increase the yield of desired transgenic products is to use strong promoters to control the expression of the transgene. Although many such promoters have been identified and characterized, the increase obtainable from a single promoter is ultimately limited to a certain extent. RESULTS: In this study, we report a method to magnify the effect of a single promoter by using a weak promoter-based selection system in transgenic rice. tCUP1, a fragment derived from the tobacco cryptic promoter (tCUP), was tested for its activity in rice by fusion to both a ß-glucuronidase (GUS) reporter and a hygromycin phosphotransferase (HPT) selectable marker. The tCUP1 promoter allowed the recovery of transformed rice plants and conferred tissue specific expression of the GUS reporter, but was much weaker than the CaMV 35S promoter in driving a selectable marker for growth of resistant calli. However, in the resistant calli and regenerated transgenic plants selected by the use of tCUP1, the constitutive expression of green fluorescent protein (GFP) was dramatically increased as a result of the additive effect of multiple T-DNA insertions. The correlation between attenuated selection by a weak promoter and elevation of copy number and foreign gene expression was confirmed by using another relatively weak promoter from nopaline synthase (Nos). CONCLUSIONS: The use of weak promoter derived selectable markers leads to a high T-DNA copy number and then greatly increases the expression of the foreign gene. The method described here provides an effective approach to robustly enhance the expression of heterogenous transgenes through copy number manipulation in rice.