Pathogenicity and whole-genome analysis of a Siniperca chuatsi-derived Nocardia seriolae strain

A bacterial strain (No. 20230510) was isolated from the kidneys of diseased Siniperca chuatsi in Guangxi, China, since 2023. Artificial infection experiments demonstrated that this strain caused the observed disease in S. chuatsi. The isolate underwent morphological, pathological, genomic (whole-genome sequencing, WGS), and antibiotic susceptibility analyses. Infection trials revealed 100% mortality in high-concentration groups, with an LD50 of 3.89 × 104 CFU/mL, indicating high virulence. WGS results showed a circular chromosome of 8,123,106 bp (GC content: 68.14%), containing 7,638 CDSs, 72 tRNAs, and 12 rRNAs. Phylogenomic analysis revealed that strain 20230510 (CP130742) clusters with three N. seriolae strains with 98% bootstrap supporting, confirming its identification as N. seriolae. Further analysis identified 403 potential virulence genes linked to nutrient metabolism, regulatory factors, immune modulation, effector delivery systems, and exotoxins. Chromosomal comparisons also detected multiple antibiotic resistance genes. Susceptibility testing confirmed sensitivity to nine antibiotics, including enrofloxacin, doxycycline, florfenicol, and sulfamethoxazole. Histopathology revealed chronic granulomatous lesions, most severe in the kidneys, with similar but milder damage in the liver, spleen, gills, and intestines. These results confirm N. seriolae strain 20230510 as the pathogenic agent behind S. chuatsi mortality, offering key insights for developing control strategies

Mechanism of swertiamarin and novel nitrogen-containing metabolites (R)-Gentiandiol and (S)-Gentiandiol in treating non-alcoholic fatty liver disease in rats: an untargeted metabolomics study based on UPLC-Q-TOF/MS

Swertiamarin, a predominant iridoid glycoside from hepatoprotective Swertia herbs, is biotransformed in vivo into nitrogen-containing metabolites (R)-gentiandiol and (S)-gentiandiol. These metabolites may be the real active hepatoprotective agents. A high-fat diet-fed rat model was treated for 12 weeks with swertiamarin, (R)-gentiandiol, (S)-gentiandiol and silybin, and the therapeutic effects on non-alcoholic fatty liver disease (NAFLD) were systematically evaluated through biochemical indices and histopathological observations. Swertiamarin and (R)-gentiandiol reversed high-fat diet-induced metabolic disturbances, reduced serum alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglyceride, low-density lipoprotein cholesterol and malondialdehyde, while elevated high-density lipoprotein cholesterol, superoxide dismutase and glutathione peroxidase. However, (S)-gentiandiol exhibited no efficacy. The differential biomarkers in the serum of high-fat diet-fed rats were determined and identified by the metabolomics method combined with multivariate analysis. The results of enrichment analysis showed that NAFLD could be improved by swertiamarin and (R)-gentiandiol by regulating the levels of 21 biomarkers, such as stearic acid, palmitic acid and PC (36:3). According to the pathway enrichment results, swertiamarin and (R)-gentiandiol had potent combined effects in regulating taurine and hypotaurine metabolism, arachidonic acid metabolism, etc. This study is the first verification of the metabolite activity in the NAFLD model, and the dose-dependent effects of (R)-gentiandiol can be used to underscore its central role in swertiamarin’s bioactivity. These findings offer valuable insights to clarify the pharmaceutical material for hepatoprotective effect of Swertia herbs

Karst tiankengs as refugia for indigenous tree flora amidst a degraded landscape in southwestern China

AbstractWe conducted floristic and community analyses to compare the floristic composition, forest structure, taxonomic richness, and species diversity between two tiankeng (large doline, or sinkhole) habitats and two outside-tiankeng habitats of forest fragments in a degraded karst area in southwestern China. We found remarkably higher taxonomic richness in the tiankeng habitats than in the outside-tiankeng habitats at the species, generic, and familial levels. The inside-tiankeng habitats had higher floristic diversity but lower dominance. The remarkably higher uniqueness at all taxonomic levels and the much larger tree size in the two tiankeng habitats than in the outside-tiankeng habitats demonstrated the old-growth and isolated nature of the tiankeng flora. Plot-scale species richness, Shannon-Wiener index, Pielou’s evenness, and Berger-Parker dominance significantly differed across habitats. Heterogeneity in floristic composition at the species, generic, and familial levels was extremely significant across habitats. In pairwise comparisons, except for the Chuandong Tiankeng-Shenmu Tiankeng pair, all the pairs showed significant between-habitat heterogeneity in floristic composition. Our results suggest that as oases amidst the degraded karst landscape, tiankengs serve as modern refugia that preserve old-growth forest communities with their rich floristic diversity, and can provide a model for habitat conservation and forest restoration in that area.</jats:p

Risk factors for hypoactive delirium in patients with nontraumatic ARDS: a prospective observational study

Abstract To investigate the incidence, characteristics and risk factors for hypoactive delirium in patients with nontraumatic acute respiratory distress syndrome (ARDS) and to explore the independent risk factors associated with hypoactive delirium and provide new ideas for early prediction and treatment. Hypoactive delirium is a known serious complication in ARDS patients, and currently, there are no effective early detection models or clinical prediction tools, and there is a lack of clinical treatment. This study included nontraumatic ARDS patients who stayed in the intensive care unit (ICU) for more than 24 h and were older than 18 years. A total of 205 ARDS patients admitted to the ICU of Gansu Provincial People's Hospital between December 2021 and February 2023 were selected. Demographic data, clinical characteristics and laboratory test results were collected within 24 h after the patients entered the ICU. Multivariate logistic regression analysis was used to investigate risk factors, evaluate the clinical prediction effect of the model and construct a nomogram for visual display. The incidence of hypoactive delirium among the patients included in the study was 41%. Patients with hypoactive delirium had hypertension; diabetes mellitus; Acute Physiology and Chronic Health Evaluation II (APACHE II) scores ≥ 15; and increased procalcitonin, C-reactive protein (CRP), lactic dehydrogenase and interleukin-6 (IL-6) levels compared with those without hypoactive delirium. Logistic regression analysis revealed that diabetes mellitus (OR 3.305, 95% CI: 1.866–12.616; p = 0.047), CRP level (OR 1.002, 95% CI: 1.001–1.023; p = 0.044), and IL-6 level (OR 1.045, 95% CI: 1.017–1.063; p = 0.001) were independent risk factors for hypoactive delirium. After receiver operating characteristic (ROC) curve analysis, calibration plot and decision curve analysis (DCA) confirmed that the clinical prediction ability of this study model was satisfactory, and a nomogram was drawn for visual display. Hypoactive delirium is a common serious complication in nontraumatic ARDS patients. Our logistic regression model not only effectively predicts hypoactive delirium early but also reveals potential clinical therapeutic targets

Antimetastasis Effect of<i> Astragalus membranaceus</i>-<i>Curcuma zedoaria</i> via <i>β</i>-Catenin Mediated CXCR4 and EMT Signaling Pathway in HCT116

Astragalus membranaceus and Curcuma zedoaria, two traditional Chinese medicines, are widely used together in colorectal cancer adjuvant treatment. Many different mechanisms should be involved in the benefit effect of Astragalus membranaceus and Curcuma zedoaria. In this study, we established that the combined extract from Astragalus membranaceus and Curcuma zedoaria (HQEZ) decreased the metastasis ability in colorectal cancer cells (HCT116, a cell line of colorectal carcinoma established from Homo sapiens) in vitro, and the treatment induced the downregulation of EMT signal and decreased CXCR4 expression and the level of β-catenin. Overexpression of CXCR4 and the administration of the agonist and inhibitor to β-catenin signal pathway were used to explore the mechanism of Astragalus membranaceus and Curcuma zedoaria in colorectal cancer treatment. The data demonstrated that HQEZ increased the phosphorylation of β-catenin which related to the degradation of β-catenin, and it induced the downregulation of EMT signal and CXCR4. It meant that the influence of β-catenin should be a key event in the antimetastasis effects of Astragalus membranaceus-Curcuma zedoaria in colorectal cancer model. These findings revealed the potential effect and mechanism of Astragalus membranaceus-Curcuma zedoaria in colorectal cancer treatment and provided insight for optimization of the usage.</jats:p