Search

In mid-2020, using next-generation sequencing (NGS) technology, we identified a recombinant cluster 2 avian orthoreovirus (ARV) variant named PHC-2020-0545, isolated from tendons of 33-day-old broilers with leg swelling in China. Complete genomic sequencing and analyses demonstrated that the isolate was genetically significantly distinct from known ARV strains in M1 and M3 genes and its σC coding gene had an extremely high variability, compared with the identified ARV strains grouped into other genotyping cluster. Further analysis showed that many base substitutions were silent and non-silent substitutions are most likely to occur in the first positions of codons. Multiple segmental recombination, intra-segmental recombination and accumulation of point mutations might contribute to the emergence of this isolate. The PHC-2020-0545 strain had a strong replication ability in 1-day-old broilers, and mainly affected the movement, digestion and metabolism of broilers. In addition, the infection route of the isolate is related to its pathogenicity to broilers. Therefore, combined with its unique genetic characteristics and potential origin, we determined that the PHC-2020-0545 field strain is a novel recombinant ARV strain, which has certain reference value for the preparation and evaluation of new vaccines.

Hydropericardium hepatitis syndrome (HHS) is a fatal disease caused by fowl adenovirus serotype 4 (FAdV-4). Avian viral arthritis is an infectious disease characterized by movement disorders caused by avian orthoreovirus (ARV). In the early 2019, our epidemiologic survey on poultry diseases in eight commercial broiler farms in China showed that FAdV-4 and ARV have a high coinfection rate, accounting for 63 % of all ARV-positive samples. We designed chicken embryo and animal models to investigate the synergistic pathogenicity of FAdV-4 and ARV. Weakness and inappetence were observed in all specific-pathogen-free (SPF) chickens of the experimental group. FAdV-4 and ARV coinfection caused severe embryonic body and hepatic hemorrhage in SPF chicken embryos. Compared with the singular ARV-infected group, joint swelling was more severe in all coinfected groups. Compared with single virus infection, the coinfection of the two viruses increased the mortality of SPF chicken embryos and chickens. FAdV-4 and ARV coinfection resulted in significantly severe macroscopic and microscopic lesions of the liver, spleen, and kidney of SPF chickens. The detection results of viral load in allantoic fluid, liver, and cloacal swabs indicated that ARV enhanced FAdV-4 replication in SPF chicken embryos and chickens. Cytokine detection showed a significant change in interleukin-1 (IL-1), IL-6, and interferon-α (IFN-α) levels in coinfected groups compared with those in the single-infected groups. Additionally, FAdV-4 and ARV coinfection caused severe damage to the SPF chicken's immune system. In summary, these findings provide insights into the pathology, prevention, and treatment of FAdV-4 and ARV coinfection.

Chemical composition, anti-inflammatory activity, and cytotoxicity of essential oils obtained from the aerial parts of Trachydium roylei were investigated in this study. The chemical composition of T. roylei essential oil was analyzed using gas chromatography mass spectrometry. Fifty-nine components, representing 98.87% of the oils, were characterized. The oils were predominated by aromatic compounds and monoterpene hydrocarbons, and the main components were myristicin (25.35%), β-phellandrene (22.95%), elemicine (7.69%), isoelemicin (5.48%), and cedrol (5.26%). The anti-inflammatory activity of the oil in lipopolysaccharide-stimulated murine RAW 264.7 cells was evaluated. The oils downregulated the production of proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1β, and IL-6, and significantly increased the anti-inflammatory cytokine IL-10 levels. Results indicated that the oils effectively inhibited the secretion of nitric oxide and prostaglandin E2 in lipopolysaccharide-stimulated macrophages. Western blot analyses were performed to determine whether the inhibitory effects of the oils on proinflammatory mediators (nitric oxide and prostaglandin E2) were related to the modulation of inducible nitric oxide synthase and cyclooxygenase-2 expression. These findings suggest that T. roylei essential oils exert an anti-inflammatory effect by regulating the expression of inflammatory cytokines.

A stepwise ethanol-precipitation (SEP) procedure was developed for the purification of sugar beet pectins (SBP) from a pectin-containing aqueous extract. Five fractions of different chemical and molecular characteristics were produced by stepwise elevating the alcohol concentration of the precipitation medium from 50% to 80% v/v. Comparison of chemical and macromolecular features between the obtained fractions indirectly suggested that the ability of pectin to solubilize in the ethanol-water binary mixture depended greatly on the polymer structure. Fractions rich in neutral sugars were precipitated at relatively high ethanol concentrations, probably due to the enhanced interactions generated between pectin side chains and solvent molecules. Furthermore, the obtained fractions displayed different surface activities. Results obtained in this work indicate that the SEP procedure is more selective with respect to pectin structural features and surface properties than the one-step ethanolic precipitation.

Metal precipitation is an effective method for the purification of pectins. To study the selectivity of copper ions toward binding pectic or non-pectic compounds, two fractions, namely copper-precipitated pectins (CPP) and copper-unprecipitated pectins (CUP) were fractionated from the mother sugar beet pectins by means of copper precipitation. Comparison on chemical feature revealed the isolated fractions were structurally different in that CUP contained markedly higher neutral sugars (NS) and protein contents, but lower galacturonic acid and acetyl ester group contents than CPP. However, no appreciable difference was observed in terms of degree of methylation (DM). Elution profiles on high performance size exclusion chromatograph showed that CPP exhibited a monomodal-like molecular weight distribution (MWD), while CUP demonstrated a multimodal-like MWD pattern composed of three relatively broad peaks, and a narrow peak that was associated with a high intensity of UV signal at 278 nm. Moreover, AFM analysis showed that CPP displayed branched fibrous structures, while CUP showed distinguishable granular-like shapes. Results obtained in this work indicate the employed copper ions selectively bind the anionic regions among pectin chains, thereby separating pectic saccharides from non-uronide compounds, i.e. low molecular weight carbohydrates and free proteins. The poor affinity of copper ions toward CUP might be determined by the absence of typical homogalacturonan (HG) regions.

Effects of precipitation modes on the co-precipitation of insoluble oxalates particles during the purification of sugar beet pectins (SBP) from the extract were investigated. It was observed that soluble oxalate ions formed insoluble oxalate salts with calcium and precipitated with pectins during ethanol precipitation as pH of the medium increased and the solvent changed from water to ethanol-water mixture. Comparison among the employed precipitation methods revealed that both the dialysis-ethanol-precipitation and metal precipitation effectively prevented the calcium-oxalate contamination of SBP. Emulsifying properties of DEPP, EPP and MPP were also studied. It was observed that DEPP performed better than the remainder with respect to emulsifying ability. Based on these results, we concluded that the dialysis-ethanolic-precipitation can be a suitable method for improving the purity as well as emulsifying properties of the resulting pectins.

This paper was aimed at characterising the insoluble substances (IS) responsible for the turbidity of the extract and impurity of the resulting pectins. Results showed that the IS caused a significant increase in the turbidity of the extract. The IS had bi-pyramidal shapes under the SEM observation. The observed XRD peaks for the IS were similar to those of calcium oxalate dihydrate (COD). Moreover, the IS consisted of mainly oxalate and calcium. Results from the present study indicate the IS is COD. The influence of the IS on the purity of pectin was also studied. The presence of the IS in the pectins indicated the IS can precipitate with pectins during the alcohol precipitation, thereby contaminating the resulting pectins.

Antioxidant and antimicrobial activities of the essential oil and n-hexane (HEE), chloroform (CHE), ethyl acetate (EAE), and methanol (MEE) extracts, respectively, from the root of Saurauia lantsangensis Hu were investigated. The GC-MS analysis revealed 39 compounds representing 96.41% of the oil containing T-muurolol (13.85%), acetophenone (7.46%), α-cadinol (6.26%), methyl palmitate (5.36%), n-hexadecanoic acid (4.31%), torreyol (3.69%), and isospathulenol (3.48%) as major components. Antioxidant activities determined by three various testing systems, i. e. DPPH radical scavenging, superoxide anion radical scavenging, and reducing power assay, increased in the order: HEE < CHE < oil < MEE < EAE. CHE, EAE, MEE and oil exhibited a promising antimicrobial effect determined as the diameter of zones of inhibition (13.3 - 16.2, 16.5 - 20.4, 13.5 - 16.6, and 16.5 - 22.7 mm), respectively, along with their respective MIC values (500 - 1000, 125 - 500, 250 - 500, and 250 - 500 μg/ml) against Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli), Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus), and a yeast (Hansenula anomala).

Human copper/zinc superoxide dismutase from recombinant Pichia pastori (RH-Cu/Zn-SOD) was orally administered, via gavage, to Sprague-Dawley rats at 500, 1,000, and 2,000 mg/kg body weight/day for 28 days. During the 28-day period, animals were examined for evidence of toxicity; there were no deaths, and in-life physical signs were normal. On day 29, the animals were exsanguinated, examined for gross pathology, and tissues were preserved for histopathology. Although statistical differences were noted in some hematology and clinical chemistry, they were of questionable biological significance. The results of the 28-day oral administration demonstrated a lack of toxicity of RH-Cu/Zn-SOD in rats. There were no treatment-related, toxicologically relevant changes in clinical signs, growth, food consumption, hematology, clinical chemistry, organ weights, or pathology. The no observed adverse effect level was greater than 2,000 mg/kg/day for RH-Cu/Zn-SOD in rats.