Metabolism Biosynthesis Research Articles

Epigenetic Modulation Directs Recovery Post LASIK and SMILE Surgery: An Experimental Study

Purpose: refractive surgery, such as LASIK and SMILE, induces a wound healing response that leads to significant corneal stromal remodeling. We have shown that the protein profile in the stroma changes dramatically immediately post-surgery. However, the methylation status of the DNA post-refractive surgery remains unknown. Design/Participants: DNA methylation study. Refractive surgery (SMILE/LASIK) performed on donor eye globes. Method: we investigated the epigenetic changes post-surgery in relation to long term ECM remodeling in an experimental ex vivo study design. Donor globes (n = 19) were obtained from the eye bank. Three globes served as non-surgical controls while SMILE (-6DS) and LASIK surgery (-6DS) were performed on eight globes each and incubated for 3 days and 2 weeks (n = 4 per group per time point). Here, we compared the DNA methylation landscapes of LASIK and SMILE stroma using the Illumina Infinium Human Methylation 850 EPIC array (HM850). Results: significant changes in DNA methylation patterns were observed post-operatively in both LASIK and SMILE groups. Specific genes involved in the activation of actin cytoskeleton and inflammation (smad3, prkca and ssh2) showed hypomethylation in LASIK after 2 weeks and LASIK SMILE after 3 days, respectively, suggesting their active role in corneal repair. The genes (gaa, gstm1, mgat1, galnt9 and galnt5) involved in sphingolipid metabolism and mucin biosynthesis showed hypomethylation in SMILE after 3 days. Conclusions: our results suggest that altered DNA methylation patterns may have relevance to the development of complications of haze post-refractive surgery. It also presents the opportunity to utilize drugs that regulate chromatin remodeling for optimal outcomes.

Modulation of Gut Mycobiome and Serum Metabolome by a MUFA-Rich Diet in Sprague Dawley Rats Fed a High-Fructose, High-Fat Diet

The intake of oleic acid-rich fats, a hallmark of the Mediterranean diet, has well-documented beneficial effects on human metabolic health. One of the key mechanisms underlying these effects is the regulation of gut microbiota structure and function. However, most existing studies focus on gut bacteria, while gut fungi, as a vital component of the gut microbiota, remain largely unexplored. This study compared the effects of regular peanut oil (PO) and high-oleic acid peanut oil (HOPO) on the gut mycobiome and serum metabolome employing ITS high-throughput sequencing and UPLC-MS/MS metabolomics to explore how dietary fatty acid composition influences gut microecology. Both HOPO and PO effectively reversed high-fat, high-fructose diet (HFFD)-induced reductions in gut fungal diversity, with HOPO showing superior efficacy in restoring gut microbiome balance, as reflected by an improved fungal-to-bacterial diversity ratio and reduced abundance of pathogenic fungi such as Aspergillus, Penicillium, and Candida. Furthermore, HOPO demonstrated a greater ability to normalize serum bile acid levels, including taurochenodesoxycholic acid, and to reverse elevated pantothenol levels, suggesting its potential role in maintaining bile acid metabolism and CoA biosynthesis. In summary, HOPO is more effective than PO in maintaining the normal structure and function of gut mycobiome in HFFD-fed SD rats.

Integrated transcriptomic and metabolomic analyses reveal critical gene regulatory network in response to drought stress in Dendrobium nobile Lindl

BackgroundDendrobium nobile Lindl belongs to the genus Dendrobium of the orchid family and is a valuable herbal medicine. Drought stress severely affects the growth of D. nobile Lindl; however, the specific regulatory mechanisms have not yet been elucidated.ResultsIn the present study, we conducted a combined transcriptome and metabolome analysis of D. nobile Lindl stems under different drought stress conditions. Global transcriptomic changes were detected in Dendrobium under different drought stress conditions. KEGG enrichment analysis showed that the DEGs were enriched in plant hormone signal transduction; cutin, suberin, and wax biosynthesis; starch and sucrose metabolism; and the biosynthesis of various plant secondary metabolites. The differentially abundant metabolites (DAMs) detected using STEM analysis were enriched in pathways associated with glucosinolate biosynthesis and cyanoamino acid metabolism. We constructed a regulatory network for the drought tolerance of Dendrobium by weighted gene co-expression analysis.ConclusionsThe results showed that arginine and proline metabolism, glucosinolate biosynthesis and tyrosine metabolism pathways participated in regulating drought stress in D. nobile Lindl. Our study provides a theoretical basis for studying the drought resistance mechanisms in Dendrobium.

Altered gut microbiome and serum metabolome profiles associated with essential tremor.

The genetic predisposition and environmental factors both trigger the complex neurological dyskinesia of essential tremor (ET). Gut dysbiosis may facilitate the occurrence and development of neurological diseases. Therefore, it is worth exploring the inner connections between gut microbiota and ET.First, the gut microbiota of 19 ET patients and 21 healthy controls (HCs) were analysed with metagenomics approach. Second, the potential linkages between gut microbiome and serum metabolome profiles were explored by integrative analysis.The gut microbiota disorders were present in ET patients. The LEfSe method showed a significant decrease in Bacteroides. The functional analysis revealed that there were differences in gut microbial apoptosis, retinol metabolism, and steroid hormone biosynthesis pathways. The levels of various lipids and lipid-like molecules alter in serum of ET patients, which correlated with altered gut microbial abundance, indicating the alterations in lipid metabolism involved in apoptosis pathway in ET.All of these data point to the gut dysbiosis in ET, and some changed gut microbial species were linked to abnormalities in blood lipid metabolism, which open up new avenues for investigation into the pathophysiology of ET.

Transcriptome Analysis Revealed the Regulatory Mechanism of DIMBOA Affecting Early Somatic Embryogenesis in Dimocarpus longan Lour.

Dimocarpus longan Lour. is an evergreen tree of the genus Longan in the Sapindaceae family, native to tropical and subtropical regions. Longan embryonic development is closely related to fruit set and fruit quality. An in-depth study of the mechanism of longan embryonic development could therefore contribute to the development of the longan industry. DIMBOA is the principal compound representing benzoxazinoids (BXs), and is closely linked to auxin biosynthesis and signal transduction. Auxin is one of the crucial hormones for inducing somatic embryogenesis (SE) in plants. Previous research has shown that DIMBOA promotes morphogenesis in the early somatic embryogenesis of longan, but the specific regulatory mechanism has not yet been clarified. To elucidate the molecular mechanism by which DIMBOA affects early somatic embryogenesis in longan, we chose longan embryogenic cultures grown under 0 mg/L DIMBOA as the control group (the check, CK), and longan embryogenic cultures grown under 0.1 mg/L DIMBOA as the treatment group (D) to be analyzed by transcriptomic sequencing. A total of 478 differentially expressed genes (DEGs) are detected in check vs. D, of which 193 are upregulated and 285 are downregulated. These DEGs are significantly enriched in the biosynthetic and metabolic functions of various substances such as vitamin B6 (VB6) biosynthesis, phenylpropanoid pathways, and carbohydrate metabolism. DIMBOA affects SE processes in longan via TFs, including MYB, ZF, bHLH, LBD, NAC, WRKY, etc. After DIMBOA treatment, the expression of most of the key genes for IAA synthesis was significantly downregulated, VB6 content was significantly reduced, and H2O2 content was significantly increased. Therefore, it is suggested that DIMBOA directly or indirectly affects the H2O2 content through the VB6 metabolic pathway, thereby regulating the endogenous IAA level to modulate the early SE morphogenesis of longan.

Physiological Responses and Metabolic Characteristics of Proso Millet Under Drought Stress During Germination Period.

To clarify the impact of drought stress during germination on proso millet's physiological responses and metabolic features, this study used physiological and targeted-like metabolomics methods. With Longmi No. 7 (drought-tolerant, L1) and Longmi No. 15 (drought-sensitive, L2) as materials, we studied the enzyme activities, osmotic adjustment substances, and differential metabolites of proso millet. Results showed that under drought stress, L1's enzyme activities and osmotic adjustment substance contents were significantly higher than L2's, especially at 48-h treatment. 1085 known metabolites were identified from 24 samples, under normal germination, L1's main differential metabolites (amino acids, flavonoids, phytohormone, lipids, sugars, etc.) were enriched in amino acid, lipid, sugar, and energy metabolism pathways. L2's (amino acids, sugars, flavonoids, etc.) were in sugar, lipid metabolism, secondary metabolite biosynthesis, and amino acid metabolism pathways. At 24-h treatment, the metabolic pathways of L1 were mainly concentrated in carbohydrate and nucleotide metabolism, while those of L2 were mainly in carbohydrate and lipid metabolism. At 48 h, the metabolic pathways of L1 were mainly in carbohydrate, energy and lipid metabolism, and those of L2 were mainly in carbohydrate, lipid metabolism, biosynthesis of other secondary metabolites and amino acid metabolism. Under stress, L1's main differential metabolites were organic acids, sugars, flavonoids, amino acids, etc.; L2's were phytohormones, organic acids, sugars, flavonoids, amino acids. This study provides a new direction for the development of proso millet sprouts. Meanwhile, it offers new ideas and theoretical bases for the development of functional foods and the regulation of nutritional components of proso millet.

Non-targeted metabonomics reveals the effect of linalyl alcohol on Brochothrix thermophile and its potential application.

Brochothrix thermophcta (B. thermophcta) is a pathogenic microorganism associated with food contamination. Linalyl alcohol, owing to its broad spectrum and exceptional antibacterial properties, is regarded as a potent natural antimicrobial agent. This is to elucidate the cellular-level mechanism of linalyl alcohol on B. thermophacta and investigate, for the first time, its regulatory effect on the metabolic pathway of B. thermophacta through metabonomics analysis. The results demonstrated that treatment with linalyl alcohol led to a reduction in bacterial metabolic capacity, while simultaneously promoting an increase in membrane fluidity through damage to the bacterial cell membrane. A total of 201 differential metabolites were identified at the metabolic level, with 50 showing significant up-regulation and 151 displaying significant down-regulation. The differential metabolites primarily participate in the tRNA cycle, amino acid metabolism, nucleotide metabolism, and aminoacyl-tRNA biosynthesis, with a particular emphasis on the significant impairment of amino acid metabolism. The application results demonstrated that linalyl alcohol exhibited a significant antibacterial effect on B. thermosphacta, as evidenced by the negligible changes observed in the color, smell, and tissue state of pork even after 8days of treatment. In summary, linalyl alcohol exhibits multi-target and multi-pathway inhibition against B. thermosphacta, leading to disruption of cell morphology and metabolic processes. These findings provide a novel theoretical foundation for understanding the inhibitory mechanism of linalyl alcohol on B. thermosphacta, highlighting its potential as an effective alternative to food additives in the preservation industry of livestock products.

Molecular characterization of ovarian mesonephric-like adenocarcinoma: Insights from single-cell RNA sequencing and mitochondrial metabolism.

Ovarian mesonephric-like adenocarcinoma (MLA) is a rare malignancy with limited understanding of its molecular features and therapeutic vulnerabilities. Although similar to uterine MLA, its unique characteristics remain undefined. This study aimed to characterize ovarian MLA using single-cell RNA sequencing (scRNA-seq) and compare it with high-grade serous ovarian cancer (HGSOC). We analyzed the cellular and molecular heterogeneity of an ovarian MLA sample using scRNA-seq. Differential gene expression and pathway analyses were performed to identify unique molecular signatures and therapeutic targets. HGSOC scRNA-seq datasets were used for comparative analysis. Ovarian MLA demonstrated reduced heterogeneity, with a predominance of epithelial cells compared to HGSOC. Transcriptomic profiling revealed an upregulation of mitochondrial metabolism and lipid biosynthesis genes, indicating a metabolic shift toward oxidative phosphorylation. Gene enrichment and protein-protein interaction analyses identified distinct pathways, including mitochondrial biogenesis and dynamics, suggesting mitochondrial reprogramming. This study provides the first scRNA-seq-based molecular characterization of ovarian MLA, differentiating it from HGSOC. Findings suggest potential therapeutic avenues, with a proposed combination therapy targeting MAP kinase and PI3K/AKT/mTOR pathways. Validation in larger cohorts is necessary for clinical application.

Metabolome-Wide Mendelian Randomization Assessing the Causal Relationship Between Blood Metabolites and Primary Ovarian Insufficiency

Background & aimsPrimary ovarian insufficiency (POI) is a significant clinical syndrome that leads to female infertility, and its incidence continues to increase. We used metabolome-specific Mendelian randomization (MR) to identify causally associated metabolites and explore the relationship between candidate metabolites and upstream genetic variations. MethodsThe primary MR analysis utilized the inverse variance weighted (IVW) method as the primary approach to assess the causal relationship between exposure and POI. Multiple sensitivity analyses included MR-Egger, weighted median, and weighted mode methods. ResultsAfter using genetic variants as probes, we identified 27 metabolites of 278 that are associated with the risk of POI, including dodecanedioate (OR 0.052, 95% CI 0.010 – 0.265; P < 0.001), adrenate (OR 0.113, 95% CI 0.016 – 0.822; P = 0.031), indolepropionate (OR 0.174, 95% CI 0.051 – 0.593; P = 0.005), homocitrulline (OR 0.194, 95% CI 0.051 – 0.741; P = 0.016), and 3-methylhistidine (OR 0.404, 95% CI 0.193 – 0.848; P = 0.017). Our study indicated the presence of heterogeneity; therefore, we employed the IVW random-effects model as the primary approach. KEGG pathway enrichment analysis identified six significant metabolic pathways, primarily including biosynthesis of unsaturated fatty acids, phenylalanine, tyrosine and tryptophan biosynthesis, aminoacyl-tRNA biosynthesis, linoleic acid metabolism, valine, leucine and isoleucine biosynthesis, ubiquinone and other terpenoid-quinone biosynthesis. ConclusionsBy integrating genomics and metabolomics, this study provides novel insights into the causal relationship linking circulating metabolites and the onset of POI.

Allelopathic influence of usnic acid on Physcomitrium patens: A proteomics approach.

Allelopathy, the chemical interaction of plants by their secondary metabolites with surrounding organisms, profoundly influences their functional features. Lichens, symbiotic associations of fungi and algae and/or cyanobacteria, produce diverse secondary metabolites, among other usnic acid, which express to have potent biological activities. Mosses, i.e. Physcomitrium patens, share the habitat with other organisms including lichens, experiencing the allelopathic effects of their metabolites. In this study, we investigated the interference of usnic acid on P. patens as inferred by proteomics, shedding light on the physiological response of this moss. Our results revealed spreading inhibition of of P. patens, under usnic acid treatment (reduction of protonemal patches and enhanced gametophore growth), along with significant alterations in the moss proteome. The results showed that structural proteins and those involved in vital life function are stable or even increased under the treatments. Thus, proteins associated with photosynthesis, stress response, and defense mechanisms were up-regulated, while those involved in energy metabolism and protein biosynthesis were down-regulated. These findings enhance our understanding of moss responses to allelopathic stress and lay the groundwork for future investigations into the functional significance of specific proteins in moss adaptation to environmental challenges.

Soybean bioactive peptide supplementation improves gut health and metabolism in broiler chickens.

This study aimed to investigate the effects of soybean bioactive peptide (SBP) on the growth performance and intestinal health of yellow-feathered broilers and to further elucidate the regulatory mechanisms of intestinal health using multi-omics analysis. A total of 320 1-day-old yellow-feathered broilers were randomly divided into two groups, with 10 replicates per group and 16 birds per replicate. Broilers in the control group received the basal diet, and those in the experimental group (SBPG) received the basal diet with 0.2 % SBP replacing the same amount of soybean meal. The experiment lasted for 70 d. The results showed that, compared with those in the control group, the final body weight and average daily gain of SBPG broilers were significantly higher (P < 0.05), and the feed conversion ratio was significantly lower (P < 0.05). Notably, SBP significantly improved gut health in chickens, including increased intestinal villus height, decreased levels of proinflammatory factors, such as IL-1β and interferon-γ, and upregulated expression of tight junction proteins, such as ZO-1 and occludin. In addition, transcriptome sequencing results revealed that broilers in the SBP group exhibited significant enrichment in multiple metabolic pathways, including fatty acid metabolism, fatty acid degradation, and the biosynthesis of unsaturated fatty acids (P < 0.05). Cecal 16S rRNA sequencing showed that SBPG increased the abundance of the butyrate-producing beneficial bacteria Muribaculaceae. Subsequent cecal metabolome analysis also revealed that SBPG enhanced lipid-related metabolic pathways, such as alpha-linolenic acid metabolism and GPI-anchor biosynthesis. In conclusion, SBP is a potential feed additive that can improve intestinal morphology, enhance intestinal immunity and barrier function, optimize the structure of the intestinal microbiota, and enhance metabolic function.

Farfarae Flos Mitigates Cigarette Smoking-Induced Lung Inflammation by Regulating the Lysophosphatidylcholine Biosynthesis and Tryptophan Metabolism.

An increased risk of developing respiratory diseases has been linked to exposure to cigarette smoking (CS). The flower buds of Tussilago farfara L., also known as Farfarae Flos (FF), can be used for the treatment of cough, bronchitis, and asthmatic disorders in China. In the present study, we used lung and fecal metabolomics, as well as the intestinal flora analysis, aimed to investigate the protective effect of FF against the CS exposure induced lung inflammation on mice. The results showed that FF administration could relieve the lung inflammation as demonstrated by lung index, interleukin-6 (IL-6), and interleukin-1β (IL-1β) levels, as well as the pulmonary pathological change. The lung metabolomics coupled with molecular docking showed that FF could alleviate lung inflammation by regulating lysophosphatidylcholine biosynthesis through the caffeoyl quinic acids distributed in the lung tissue. In addition, fecal metabolome coupled with 16S rRNA gene sequencing showed that FF could regulate the tryptophan metabolism by regulating the intestinal flora disorders. This study provided new insights of FF to relieve CS-induced pulmonary inflammation with the multimechanism.

Bangia fusco-purpurea polysaccharide with ultra-high pressure assisted extraction alleviates dyslipidemia in high-fat diet induced mice.

Bangia fusco-purpurea polysaccharide (UBFP) with ultra-high pressure assisted extraction has good in vitro hypolipidemic activity. To be explored as a natural hypolipidemic agent, the alleviation effect of UBFP on in vivo dyslipidemia in high-fat diet (HFD) induced mice was further investigated. Compared with native polysaccharide (BFP), UBFP was better to reduce weight gain, fat accumulation, serum and hepatic lipid abnormalities for HFD induced mice. This might be caused by the factor that UBFP was more effective to improve the diversity and structure of gut microbiota especially with SCFAs-producing bacteria (e.g., Allprevotella and Akkermansia) increased. Moreover, UBFP could up-regulate tryptophan, 5-hydroxyindoleacetic acid, leptin and N-arachidonic acid glutamate levels, and exhibited significant differential enrichment in the pathways of lysine biosynthesis, arginine biosynthesis, and tryptophan metabolism. In addition, UBFP could regulate energy metabolism and enhance fatty acid oxidation by inhibiting PPARγ protein expression and activating AMPK and ACC signaling pathways. Overall, with ultra-high pressure assisted extraction, UBFP possessed better function of regulating lipid homeostasis, which resulted from the altered structure of polysaccharides, improved intestinal flora and metabolites. The findings can lay the theoretical foundation for the design and development of desirable polysaccharides on regulating lipid homeostasis through ultra-high pressure modification.

Effects of dark septate endophyte on root growth, physiology and transcriptome of Ammopiptanthus mongolicus seedlings under drought stress

As the only evergreen relict species in the desert environment of western China, Ammopiptanthus mongolicus (Leguminosae) roots is colonized with dark septate endophytes (DSE), but the potential of DSE to alleviate the adverse effects of drought on seedling roots remains uncertain. This study examined the effects of DSE on root growth, physiology and transcriptome of A. mongolicus under drought stress. Drought drastically reduced root biomass by 47.7%, while all DSE strains established positive symbiosis with A.mongolicus, with G.hyphopodioides having the most pronounced promoting effect. Inoculation with G. hyphopodioides alleviated drought stress injury by increasing CAT activity, AsA content and soluble sugar content in the roots, with a significant reduction in MDA accumulation by 97.7%. G. hyphopodioides also significantly increased zeatin and brassinosteroid contents, which in turn regulated the root structure and increased root activity, resulting in a 208.6% increase in root biomass. Transcriptome analysis screened 1246 differentially expressed genes (542 up-regulated and 704 down-regulated) between G. hyphopodioides inoculation under drought treatment, mainly associated with phenylpropanoid biosynthesis, ascorbic acid and aldehyde metabolism, hormone synthesis and signalling, sucrose and starch metabolism, and vitamin B6 metabolism, and further investigated and identified key potential genes and transcription factors (DREB, ERF, NAC, MYB, C2H2). These findings reveal the physiological and molecular mechanisms by which DSE symbiosis improves the drought resistance of A. mongolicus seedlings, providing valuable guidance on the use of DSE resources to promote ecological construction and production of desert plants.

Transcriptomic analysis reveals potential roles of polyamine and proline metabolism in waterlogged peach roots inoculated with Funneliformis mosseae and Serendipita indica.

Root-associated endophytic fungi can create symbiotic relationships with trees to enhance stress tolerance, but the underlying mechanisms, especially with regard to waterlogging tolerance, remain unclear. This study aimed to elucidate the effects of Funneliformis mosseae and Serendipita indica on the growth, root cross-section structure, and root transcriptional responses of peach under waterlogging stress, with a focus on polyamine and proline metabolism. Genes and transcription factors associated with secondary cell wall biosynthesis were selected, and their expression profiles were analyzed. F. mosseae significantly increased the height, stem diameter, and leaf number of peach seedlings subjected to two weeks of waterlogging stress, whereas S. indica only significantly improved stem diameter. Both fungal species substantially increased root diameter, stele diameter, the number of late metaxylem inside the stele, and late metaxylem diameter, thus improving aeration within inoculated roots under waterlogging stress. Transcriptomic analysis of waterlogged roots identified 5425 and 5646 differentially expressed genes following inoculation with F. mosseae and S. indica, respectively. The arginine and proline metabolism and arginine biosynthesis pathways were enriched following fungal inoculations. Both fungi reduced the conversion of glutamate and ornithine for proline synthesis. However, S. indica promoted peptide-to-proline conversion by up-regulating the expression of PIPs. Although both fungi promoted the expression of genes involved in arginine and ornithine synthesis pathway, only F. mosseae led to increased levels of arginine and ornithine. Additionally, F. mosseae promoted the accumulation of putrescine and maintained polyamine homeostasis by down-regulating PAO2 and SAMDC. Moreover, F. mosseae facilitated the metabolism of cadaverine. In conclusion, both F. mosseae and S. indica formed symbiotic relationships with peach, with F. mosseae primarily improving polyamine accumulation and S. indica predominantly facilitating proline accumulation for enhanced waterlogging resistance.

Alterations in Protein Phosphorylation and Arginine Biosynthesis Metabolism Confer β-Phenylethanol Tolerance in Saccharomyces cerevisiae.

The aromatic compound β-phenylethanol (2-PE) is inherently toxic and can inhibit cell activity in Saccharomyces cerevisiae, making it highly challenging to enhance strain tolerance through rational design due to the lack of reliable connections between tolerance phenotype and genetic loci. This study employed adaptive laboratory evolution strategy to investigate the tolerance characteristics of S. cerevisiae S288C under inhibitory concentrations of 2-PE. The tolerant mutant SEC4.0 was characterized through comprehensive analysis of whole genome sequence, transcriptome, and phosphoproteome. The findings revealed that the high resistance of SEC4.0 was not primarily due to large-scale transcriptional upregulation of stress response genes, but rather through alterations in the phosphorylation levels of lipid-related pathways. PKC1 mutations that affect stress signal transduction and SPT3 mutations that affect arginine biosynthesis have been shown to significantly enhance 2-PE resistance. This study also investigated the effects of exogenous amino acid addition and synergistic effects with two key mutanted genes on 2-PE resistance. This study provides a foundation for enhancing yeast tolerance to this aromatic compound through rational design strategies.

1,3,4-Oxadiazole Sulfonamide Derivatives Containing Pyrazole Structures: Design, Synthesis, Biological Activity Studies, and Mechanism Study.

Sulfonamide derivatives have been widely used for pesticide research in recent years. Herein, 1,3,4-oxadiazole sulfonamide derivatives containing a pyrazole structure were synthesized, and their structure-activity relationship was studied. Bioactivity tests showed the remarkable efficacy of most synthesized compounds. Especially for Xanthomonas oryzae pv oryzae, A23 exhibited 100% inhibition at 100 mg/L, surpassing bismerthiazol (99.3%), and 90% inhibition at 50 mg/L, outperforming thiodiazole copper (84.5%), with an EC50 of 5.0 mg/L, markedly more active than bismerthiazol (23.9 mg/L) and thiodiazole copper (63.5 mg/L). Initial investigations into antimicrobial mechanisms involved a series of biochemical analyses, including bacterial growth rate analysis, scanning electron microscopy, bacterial biofilm formation experiments, and molecular docking analyses. Notably, A23 considerably inhibited the formation of Xoo biofilms, disrupting the integrity of bacterial cell membranes. Co-analysis of transcriptomics and proteomics revealed the capability of A23 to regulate pathways such as tryptophan metabolism and phenylpropanoid biosynthesis, enhancing the innate immunity of rice and activating its disease resistance. Thus, A23 emerges as a potential immunoinducible pesticide lead compound for the discovery of highly active immune-inducing agents.

P-306. Characterization of a Rare Hospital-Associated MRSA Lineage

Abstract Background The adaptive power of Staphylococcus aureus enables it to cause a wide variety of infections and readily develop resistance to antibiotics. It does this through extensive variability in its genomic repertoire, not only via laterally acquired elements but also through core genome evolution. Methods Herein we use whole genome sequencing to study the genomic epidemiology of S. aureus strains circulating within Tampa General Hospital (TGH). Results While characterizing the genetics of mupirocin resistance, we identified a rare ST belonging to hospital-associated clonal complex 5. The elevated rate of mupirocin resistance in this ST, ST3390 (83.2% total, high-level resistance 55.5% and low-level resistance 27.7%), was particularly striking. To date, there have only been 6 recorded instances of this lineage globally, whilst this work identified 36 individual strains from TGH alone. Genome analysis of our strains identified numerous completely conserved non-synonymous mutations in genes relating to DNA damage response, metabolism, adhesion/biofilm formation, iron acquisition and peptidoglycan biosynthesis compared to CC5 isolates. Additionally, exploration of AMR genes detected the presence of a unique dual SCCmec type, with two-thirds of strains possessing components of both SCCmecIa and SCCmecIIa. Phenotypically, all ST3390 strains lack the characteristic staphyloxanthin pigment that gives S. aureus its name. Additionally, ST3390 isolates display high levels of cytotoxicity towards human neutrophils compared to other CC5 strains. Conclusion Collectively, this work provides a deeper understanding of the genetic variability of S. aureus in clinical settings, leading to a better comprehension of in-hospital bacterial population dynamics and the evolution and spread of contemporary isolates. Disclosures All Authors: No reported disclosures

Comparison of Volatile and Non-Volatile Compounds of Ice-Stored Large Yellow Croaker (Larimichthys crocea) Affected by Different Post-Harvest Handling Methods

To compare the impact of different post-harvest handling methods on volatile and non-volatile compounds, a total of 54 live large yellow croakers were subjected to commercial slaughter (CS), spinal cord cutting (SCC), or spinal cord cutting and bleeding (SCCB). The fish samples were ice-stored for 72 h, followed by the analysis of volatile compounds using gas chromatography–ion mobility spectrometry and non-volatile compounds using LC-MS-based untargeted metabolomics. The results revealed the detection of a total of 28 volatile organic compounds, with 23 being successfully identified, predominantly including alcohols, aldehydes, esters, ketones, and heterocyclic compounds. Substances such as (E)-2-nonenal and 2-butanone are highly sensitive to post-harvest handling methods during ice storage. Furthermore, 943 non-volatile metabolites were identified, showing significant differences in 180, 100, 117, and 186 metabolites across comparisons of SCC 0 h/CS 0 h, SCCB 0 h/CS 0 h, SCC 72 h/CS 72 h, and SCCB 72 h/CS 72 h, respectively. Notably, the altered metabolic pathways mainly involved fatty acid and amino acid metabolism, including pathways like glycerophospholipid metabolism and arginine biosynthesis. This study revealed the potential mechanisms underlying the enhancement of fish quality through spinal cord cutting and bleeding.

Selenium nanoparticles enhance metabolic and nutritional profile in Phaseolus vulgaris: comparative metabolomic and pathway analysis with selenium selenate

Selenium is a beneficial element in agriculture, particularly for its potential to improve plant growth and stress tolerance at suitable concentrations. In this study, Phaseolus vulgaris was foliar-sprayed with selenium selenate (Se) or selenium nanoparticles (SeNP) at different concentrations during the vegetative stage; afterward, the seed yield was analyzed for metabolomics using 1H, J-resolved and HSQC NMR data, and NMR databases. A total of 47 metabolites were identified with sugars being the major chemical class. In the control sample, the most abundant sugar was stachyose (14.6 ± 0.8 mM). Among the identified alkaloids, the concentration of trigonelline was the highest (0.6 ± 0.08 mM). Chemometric and cluster analyses distinctly differentiated the control from the Se and SeNP-treated samples. Treatments with SeNP resulted in elevated concentrations of sugars, carboxylic acids, and sulfur-containing amino acids compared to control and Se treated samples. Conversely, betaine levels were higher in Se samples. The presence of Se and SeNP significantly decreased the levels of several aliphatic amino acids, e.g. alanine. The addition of 50 µM SeNP upregulated the levels of trigonelline and syringate by 2-fold and 1.75-fold, respectively, relative to the control. Pathway analysis indicated the most significantly altered pathways due to SeNP addition were arginine biosynthesis and nitrogen metabolism. The pathways influenced by Se addition were glyoxylate and dicarboxylate metabolism as well as glycine-serine and threonine metabolism. This study proved that SeNP are more efficient than Se in enhancing the metabolic profile of Phaseolus vulgaris which will have implications for agricultural practices, focusing on the sustainability and nutritional enhancement of crops.