Search Results (2,296)

Clinical reports have shown that administration of Nauclea officinalis (Danmu in Chinese, DM) preparations may cause significant gastrointestinal discomfort. This study aimed to systematically evaluate the adverse effects of DM and its primary active constituent, strictosamide, on gastrointestinal motility, intestinal barrier integrity, and gut microbiota homeostasis. Furthermore, we sought to investigate the potential role of the bitter taste receptor (T2R) signaling pathway in mediating these effects. In vitro cell cultures and ex vivo intestinal tissues were employed to assess cell viability and molecular alterations. In vivo studies involved short-term (2 weeks) gavage of DM (0.54 and 1.08 g/kg) and long-term (16 weeks) intervention (0.4, 0.8, and 1.2 g/kg) in rodents. Evaluations included histopathological examination, serum levels of cytokines and oxidative stress markers (ELISA), expression of tight junction proteins (Western blot and qPCR), and 16S rDNA sequencing of cecal microbiota. Mechanistic analyses focused on α-defensin secretion and T2R-associated gene and protein expression. Administration of DM resulted in significant gastrointestinal dysfunction, characterized by delayed intestinal propulsion and increased gastric retention. Dose-dependent histopathological damage, disruption of the intestinal barrier (reduced occludin and claudin-1 expression), and elevated levels of pro-inflammatory cytokines (IL-6, TNF-α, and IL-1β), oxidative stress markers (MDA, SOD, and GSH-Px), and immune mediators (IFN-γ) were observed. Gut microbiota analysis revealed dysbiosis, marked by a decline in beneficial genera (e.g., Mucispirillum, Butyricicoccus, Roseburia) and an increase in potentially pathogenic bacteria (e.g., Citrobacter, Helicobacter). Mechanistically, DM suppressed α-defensin secretion and downregulated the expression of TAS2R108, TAS2R138, and Gα-gustducin both in vitro and in vivo. DM and strictosamide disrupt gut microbiota composition and compromise intestinal barrier function, likely through inhibition of the T2R/α-defensin pathway. These findings provide important mechanistic insights into drug-induced gastrointestinal toxicity and underscore the potential risks associated with prolonged use of DM-containing preparations. Full article

Background/Objectives: Skin photoaging represents a predominant form of extrinsic aging, characterized by structural and functional impairment of the skin barrier. In severe cases, it may precipitate dermatological diseases and even tumors. Given the prevalence and detrimental effects of skin photoaging, strategies for its effective prevention and mitigation have garnered significant research interest. Chrysanthemum morifolium Ramat cv. ‘Hangju’ contains diverse bioactive compounds, including flavonoids, phenylpropanoids, phenolic acids, and polysaccharides, which have been proven to exhibit antioxidant and anti-inflammatory effects. Methods: This study employed a UVB-induced mouse model of skin photoaging to evaluate the potential of dietary supplementation with Chrysanthemum morifolium Ramat cv. ‘Hangju’ flower extract (CME) in vivo. Results: In the photoaged skin of female SKH-1 hairless mice, dietary supplementation with CME significantly increased skin moisture content, reduced wrinkle formation, suppressed epidermal hyperplasia, enhanced collagen density, and suppressed the senescence marker expression and DNA damage marker expression. Analysis of the skin transcriptome suggested that CME could alter gene expression patterns and potentially modulate critical signaling pathways involved in skin homeostasis. Moreover, 16S rRNA sequencing indicated that CME mitigated UVB-induced gut microbiota dysbiosis. Conclusions: These preclinical findings reveal the anti-photoaging property of dietary CME supplementation and point to its potential application as a functional dietary supplement for promoting skin health. Full article

Between 2015 and 2022, we evaluated a novel broad-range (BR) 16S PCR rDNA PCR/Sanger sequencing assay to improve diagnosis of invasive infections in culture-negative specimens. Using dual-priming oligonucleotides (DPO), this assay analyzed ribosomal DNA from sterile fluids or tissues. A total of 762 specimens were analyzed from 661 patients: 61% had negative cultures and BR 16S PCR tests; 35% had negative cultures but positive BR 16S PCR tests; and only 4% had negative cultures with indeterminate BR 16S PCR results. After resolution of indeterminate BR 16S PCR results (i.e., 29 negative, 1 false-positive, and 1 positive) the assay showed a sensitivity of 98.26% (95% CI = 96.00–99.43%), specificity of 99.79% (95% CI: 99.82–99.99%), positive predictive value of 99.65% (95% CI: 97.56–99.95%), negative predictive value of 98.94% (95% CI: 97.51–99.55%), and accuracy of 99.21% (95% CI: 98.28–99.71%) for a disease prevalence of 38.10% (95% CI: 34.62–41.66%). Gram stain purulence predicted the BR 16S PCR result better (69.4%) than organisms (24.6%), but the latter had a higher PPV (78.5%). Increased peripheral WBC (86.1%) or CRP (71.8%) predicted positive BR 16S PCR results. Our DPO BR 16S PCR assay improved pathogen detection over culture and minimized contamination. Broad range 16S rDNA PCR/sequencing (BR 16S PCR) is an important diagnostic technique in cases with invasive infection due to fastidious or uncultivatable pathogens. However, appropriate case selection, the quality of clinical specimen, and the specific assay primers affect its performance. Our novel BR 16S PCR assay uses unique dual-priming oligonucleotides (DPO) primers and fast protocols for rapid, optimal detection of bacterial pathogens, while minimizing contamination. Fast BR 16S PCR assay reports occurred within 24–48 h. BR 16S PCR and culture analyzed a diverse range of clinical specimens from patients with invasive infections. BR 16S PCR demonstrated a high performance for accurately detecting pathogens, ruling out infections, and minimizing contamination. BR 16S PCR detection of a pathogen allowed the appropriate clinical management of one-third of patients in this cohort. BR 16S PCR is an essential tool for the clinical management of patients with invasive infection when primary cultures are negative or contaminated. Full article

Background: Vietnam faces a hyperendemic burden of hepatitis B virus (HBV) infection, but the prevalence of occult HBV infection (OBI) and its underlying molecular mechanisms in healthy populations remain poorly understood. This study aimed to characterize the serological and molecular HBV profile of a healthy Vietnamese adult cohort in Southern Vietnam. We assessed the prevalence of occult HBV infection (OBI) and HBsAg-positivity (serving as a proxy for probable chronic infection). Methods: In this cross-sectional study, 397 healthy adults from Southern Vietnam underwent serological screening for HBsAg, anti-HBs, and anti-HBc. All participants were screened for HBV DNA using a high-sensitivity PCR assay (LOD ≥ 5 IU/mL). For all viremic cases, the full Pre-S/S region was sequenced to determine genotype and characterize escape mutations. Results: We uncovered a high prevalence of both HBsAg-positivity (17.6%) and OBI (9.3% HBsAg-negative, HBV DNA-positive). Serological analysis revealed a massive, age-dependent reservoir of past exposure (63.7% anti-HBc) characterized by a high and increasing prevalence of the anti-HBc only profile (31.5%), a key serological marker for OBI. This trend contrasted sharply with a steep age-related decline in protective anti-HBs. The viral landscape was dominated by genotypes B (73.8%) and C (26.2%), with sub-genotypes B4 and C1 being the most prevalent. Critically, individuals with OBI carried a significantly higher burden of S gene escape mutations compared to those with HBsAg-positivity (p < 0.001). Canonical escape variants, including sG145R (21.6%), sK141R/T/E/Q (24.3%), and sT116N/A/I/S (18.9%), were exclusively or highly enriched in the OBI group. A LASSO-logistic model based on this mutational profile successfully predicted occult infection with high accuracy (AUC = 0.83). Conclusions: A substantial hidden reservoir of occult HBV infection exists within the healthy adult population of Vietnam, driven by a high burden of S gene escape mutations. These findings highlight the significant limitations of conventional HBsAg-only screening. They also underscore the need for comprehensive molecular surveillance to address the true scope of HBV viremia, hopefully enabling a reduction in hidden transmission of clinically significant viral variants. Full article

A novel bacterial strain, designated as 4-30^T, was isolated from a soil sample collected from the Kubuqi Desert in Inner Mongolia, northern China. The isolate was a Gram-stain-positive, aerobic, motile, and coccus-shaped bacterium, and its colonies were circular, opaque, convex, smooth, and orange-pigmented on Luria–Bertani agar. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 4-30^T belonged to the genus Planococcus. Growth occurred at 4–38 °C (optimum, 25–28 °C), pH 6.0–11.0 (optimum, pH 9.0), and in 0–10% (w/v) NaCl (optimum, 1%). Strain 4-30^T contained iso-C_14:0, anteiso-C_15:0, C_16:1 ω7c alcohol, and iso-C_16:0 as major cellular fatty acids (>10%) and MK-7 and MK-8 as predominant menaquinones. Its polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and two unidentified polar lipids. The genomic DNA G+C content was 45.9%. The average nucleotide identity (ANI) values between strain 4-30^T and the closely related species were relatively low (ANIm < 85.6%, ANIb < 82.9% and OrthoANIu < 83.3%), and the digital DNA–DNA hybridization (dDDH) between strain 4-30^T and type strains of the genus Planococcus were 20.0–26.7%. Based on phylogenetic, genotypic, chemotaxonomic, and phenotypic analyses, strain 4-30^T is considered to represent a novel species of the genus Planococcus, for which the name Planococcus circulans sp. nov. is proposed. The type strain is 4-30^T (=CDMCC 1.2409^T = KCTC 43405^T). Full article

Microbial biological control agents are a sustainable alternative to synthetic pesticides, yet their widespread application is limited by a lack of environmental resilience of commercial products. To address this, we exploited honey—a stringent ecological niche—as a reservoir for stress-tolerant bacteria. In this study, the bioprospection utilizing five types of commercially available honeys yielded a collection of 53 bacteria and 10 fungi. All bacterial isolates were evaluated for antimicrobial activity against a laboratory-standard bacterium and yeast, and six economically relevant phytopathogenic microorganisms. Initial screening with standard laboratory organisms proved to be an efficient method to detect strains with antimicrobial potential, correlating significantly with further phytopathogen inhibition (Spearman’s r = 0.4512, p = 0.0005). Two promising strains, M2.7 and M3.18, were selected for quantitative dual-culture assays along with molecular identification using 16S rDNA and gyrA gene sequencing, classifying them as Bacillus velezensis. These strains exhibited high inhibitory effects against the pathogens (p > 0.001), often with equivalent efficacy to the commercial biocontrol strain, and also induced significant phytopathogen hyphal deformities, such as increased septation and swelling. These findings support honey as a viable source of robust biocontrol agents, offering a sustainable strategy to substitute or complement current agrochemicals. Full article

Agrobacterium tumefaciens, a destructive pathogen causing crown gall disease, results in substantial agricultural losses. Traditional chemical and existing biocontrol methods are limited by environmental pollution, pesticide resistance, and low efficacy, while bacteriophages emerge as a promising alternative due to their high host specificity, environmental compatibility, and low resistance risk. In this study, we isolated and characterized a lytic phage (PAT-A) targeting A. tumefaciens, evaluating its biological traits, genomic features, and biocontrol potential. The host strain A. tumefaciens CL-1 was isolated from cherry crown gall tissue and identified by 16S rDNA sequencing. Phage PAT-A was recovered from orchard soil via the double-layer agar method, showing a tadpole-shaped morphology (60 nm head diameter, 30 nm tail length) under transmission electron microscopy (TEM). Nucleic acid analysis confirmed a double-stranded DNA genome, susceptible to DNase I but resistant to RNase A and Mung Bean Nuclease. PAT-A exhibited an optimal MOI of 0.01, tolerated wide pH and temperature ranges, but was sensitive to UV (titer declined after 15 min of irradiation) and chloroform (8% survival at a 5% concentration). Whole-genome sequencing revealed a 44,828 bp genome with a compact structure, and phylogenetic/collinearity analyses placed it in the Atuphduvirus genus (Autographiviridae). Biocontrol experiments on tobacco plants demonstrated that PAT-A significantly reduced crown gall incidence. Specifically, simultaneous inoculation of PAT-A and A. tumefaciens CL-1 resulted in the lowest tumor incidence (12.0%), while pre-inoculation of PAT-A 2 days before pathogen exposure achieved an incidence rate of 33.3%. In conclusion, PAT-A is a novel strictly lytic phage with favorable biological properties and potent biocontrol efficacy against A. tumefaciens, enriching phage resources for crown gall management and supporting phage-based agricultural biocontrol strategies. Full article

Vagococcus species have been isolated from diverse environments, including aquatic, terrestrial, food-associated, and clinical sources; however, plant- and flower-associated representatives remain poorly characterized at the genomic level. In this study, we report the complete genomic sequence and analysis of Vagococcus sp. JNUCC 83, isolated from flowers of Camellia japonica collected on Jeju Island, Republic of Korea. The genome comprises a single circular chromosome of 2,472,896 bp with a GC content of 33.5 mol% and was assembled at high depth (555.43×), resulting in a high-quality complete genome. Genome-based phylogenomic analysis using the Type (Strain) Genome Server (TYGS) showed that strain JNUCC 83 forms a distinct lineage within the genus Vagococcus. Digital DNA–DNA hybridization (dDDH) values were far below the 70% species threshold, and 16S rRNA gene-based phylogeny consistently supported its independent placement, suggesting that JNUCC 83 represents a previously undescribed genomic species. Functional annotation based on EggNOG/COG analysis indicated the enrichment of genes involved in core metabolism and genome maintenance, while antiSMASH analysis identified a terpene-precursor-type biosynthetic locus encoding a polyprenyl synthase. Overall, this study expands the genomic understanding of flower-associated Vagococcus lineages and provides a foundation for future investigations into their ecological roles and potential applications as plant-derived microbial resources. Full article

Microbiologically influenced corrosion induced by sulfate-reducing bacteria (SRB) poses a significant threat to shale gas pipeline integrity. This study investigates an integrated control strategy combining the biocide glutaraldehyde with denitrifying bacteria (DNB) to synergistically inhibit SRB activity and corrosion. The efficacy and mechanisms were systematically evaluated using electrochemical measurements (EIS, LPR), weight-loss analysis, surface characterization (SEM, maximum pit depth), and microbial community profiling (16S rDNA sequencing). Compared to the SRB-inoculated system, the combined treatment reduced the average corrosion rate of L245 steel by 44.2% (to 0.01608 mm/a) and the maximum pit depth by 84.3% (to 1.53 μm). EIS results further confirmed the superior inhibition effect, showing the largest capacitive arc diameter and the highest polarization resistance in the combined system. Microbial community analysis indicated a substantial decline in SRB abundance from 62.7% (day 1) to 11.9% (day 14). This synergistic strategy presents an effective and more sustainable approach by reducing chemical dosage and leveraging the bio-competitive exclusion by DNB. Full article

Background/Objectives: Vedolizumab (VDZ), a monoclonal antibody targeting α4β7 integrin, is used in Crohn’s disease (CD) management, yet patients’ responses vary, underscoring the need for pharmacogenomic (PGx) markers. This study aimed to identify PGx pathways associated with suboptimal VDZ response using a rare-variant analytical framework. Methods: DNA from 63 CD patients treated with VDZ as first-line advanced therapy underwent whole-exome sequencing. Clinical response at week 14 classified patients as optimal responders (ORs) or suboptimal responders (SRs). Sequencing data were processed using GATK Best Practices, annotated with variant effect predictors, and filtered for rare damaging variants (damaging missense and high-confidence loss-of-function; minor allele frequency < 0.05). Variants were mapped to genes specific for SRs and ORs, and analyzed for pathway enrichment using the Reactome database. Rare-variant burden and composition differences were assessed with Fisher’s exact test and SKAT-O gene-set association analysis. Results: Suboptimal VDZ response was associated with pathways related to membrane transport (ABC-family proteins, ion channels), L1–ankyrin interactions, and bile acid recycling, while optimal response was associated with pathways involving MET signaling. SKAT-O identified lipid metabolism-related pathways as significantly different—SRs harbored variants in pro-inflammatory lipid signaling and immune cell trafficking genes (e.g., PIK3CG, CYP4F2, PLA2R1), whereas ORs carried variants in fatty acid oxidation and detoxification genes (e.g., ACADM, CYP1A1, ALDH3A2, DECR1, MMUT). Conclusions: This study underscores the potential of exome-based rare-variant analysis to stratify CD patients and guide precision medicine approaches. The identified genes and pathways are potential PGx markers for CD patients treated with VDZ. Full article

Gastric cancer (GC) is the fifth most common cancer worldwide, with the highest incidence in East Asia. Although H. pylori is a well-known risk factor, carcinogenesis can occur independently of H. pylori infection, and approximately 43% of adults carry H. pylori as part of their native microbiota. This study aimed to identify potential oral and gastric microbial markers across different histological stages of GC in both H. pylori-positive and -negative patients. Buccal swabs and gastric mucosa samples were collected from patients with intestinal metaplasia, low-grade dysplasia, high-grade dysplasia, early GC, or advanced GC. Total DNA was extracted, and 16S rRNA gene amplicon sequencing was performed. Microbiome diversity generally remained stable across histological stages, with no directional shifts in community structure. Differential abundance analysis revealed higher relative abundances of Anaerostipes, Phocaeicola, and Collinsella in the gastric antrum of cancerous samples. Anaerostipes and Phocaeicola are typically enriched in the intestinal microbiota but are rarely observed in the stomach, suggesting their potential ecological and pathological relevance in gastric carcinogenesis. In H. pylori-negative patients, however, a different stage-associated abundance pattern was observed, in which Faecalibacterium, a genus predominantly associated with the intestinal environment, was less abundant in advanced gastric cancer samples than in earlier histological stages within the gastric body. These findings suggest that microbial changes during gastric cancer progression may follow different trajectories depending on H. pylori infection status. In oral samples, Haemophilus and Prevotella were more abundant in intestinal metaplasia than in low-grade dysplasia, and network analysis indicated links between Neisseria and Filifactor at oral and gastric sites. However, as the study population was limited to a single country and ethnicity, the applicability of these microbial markers should be carefully considered. Full article

The forest fly (Hippobosca equina) is an obligate haematophagous dipteran insect (order Diptera) that primarily infests horses and may contribute to the circulation of vector-borne pathogens. This study aimed to investigate the presence of Anaplasma phagocytophilum, Borrelia burgdorferi s.l., Babesia caballi, and Theileria equi, important vector-borne pathogens of equids, in forest flies collected from horses in endemic areas of Spain. A total of 170 forest flies were collected from 39 equids across four geographical regions in Spain (Segovia, Madrid, Toledo, and Menorca) and blood samples were collected from 27 of these horses. All flies were morphologically and molecularly identified as H. equina, and DNA extracted from flies and equine blood was screened using multiplex real-time and nested PCR, followed by sequencing and phylogenetic analysis. Neither flies nor horses tested positive for A. phagocytophilum, whereas one fly was positive for B. burgdorferi s.l. (0.6%). In contrast, T. equi and B. caballi DNA were detected in 11.2% and 1.2% of flies, respectively, and all positive flies were collected from horses positive for equine piroplasmosis (T. equi/B. caballi infection), with identical 18S rRNA sequences between hosts and flies. Nested PCR showed a higher detection rate than real-time PCR for the detection of these piroplasms in flies and blood samples. These findings provide the first molecular evidence of EP pathogens in H. equina and support further investigation into the epidemiological importance of forest flies in equine pathogen surveillance. Full article

Sharp declines in temperature pose a significant risk for mass mortality events in the Chinese soft-shelled turtle (Pelodiscus sinensis). To assess the effects of acute cold stress on intestinal health, turtles were exposed to temperatures of 28 °C (control), 14 °C, and 7 °C for 1, 2, 4, 8, and 16 days. The results showed that acute cold stress at 14 °C and 7 °C induced time-dependent alterations in intestinal morphology and histopathology. The damage was more severe at 7 °C, characterized by inflammatory cell infiltration, lymphoid hyperplasia, and extensive detachment and necrosis across the villi, muscle layer, and submucosa. 16S rDNA sequencing revealed significant shifts in intestinal microbiota composition in the 7 °C group, dominated by Helicobacter and Citrobacter. Transcriptomic analysis identified differentially expressed genes (DEGs) that respond to acute cold stress and are involved in the Toll-like receptor signaling pathway (Tlr2, Tlr4, Tlr5, Tlr7, and Tlr8), the NOD-like receptor signaling pathway (Traf6, Traf2, Casr, Rnasel, Pstpip1, Plcb2, Atg5, and Mfn2), apoptosis (Tuba1c, Ctsz, Ctsb, Kras, Hras, Pik3ca, Bcl2l11, Gadd45a, Pmaip1, Ddit3, and Fos), and the p53 signaling pathway (Serpine1, Sesn2, Ccng2, Igf1, Mdm2, Gadd45a, Pmaip1, and Cdkn1a). Metabolomic profiling highlighted differentially expressed metabolites (DEMs) that cope with acute cold stress, such as organic acids (oxoglutaric acid, L-aspartic acid, fumaric acid, DL-malic acid, and citric acid) and amino acids (including L-lysine, L-homoserine, and allysine). The integrated analysis of DEGs and DEMs underscored three key pathways modulated by acute cold stress: linoleic acid metabolism, neuroactive ligand–receptor interaction, and the FoxO signaling pathway. This study provides a comprehensive evaluation of intestinal health in Chinese soft-shelled turtles under acute cold stress and elucidates the underlying mechanisms. Full article

Three common agricultural beneficial microbes, Trichoderma harzianum, Bacillus cereus, and Pseudomonas fluorescens, are widely used in the growth cycle of crops, and increase the yield of agricultural products through disease prevention and sterilization. As a biodegradable biological macromolecular material, polylactic acid (PLA) is also widely used in agricultural production as a biodegradable film. The addition of agricultural microbes will affect the degradation rate of polylactic acid and thus its agricultural use. Under specific conditions (Tri15), the degradation rate of PLA film exceeds 30%. Scanning electron microscopy (SEM) images show that the degradation of the PLA happened after 360 days of exposure to these three specific microbe environments, which makes the surface of PLA films crack. Gel permeation chromatography (GPC) analysis reveals that in the presence of these microbes, the molecular weight of PLA is reduced. The analysis of 16S rDNA sequences demonstrates that the introduction of these microbes alters the soil microbial community, resulting in an enhanced abundance of Betaproteomicrobes, promoting the degradation of PLA. These results indicate that the three microbes species significantly promote the degradation of PLA, and the effects of microbes vary for the different concentrations. This study establishes practical guidelines for the deployment of PLA in real-world farmland environments. Full article

Ultraviolet (UV) radiation is a primary environmental factor responsible for skin photodamage, and exposure to UV rays is strongly linked to a variety of skin diseases. This study examined the prophylactic and therapeutic effects of Seed Oil of Lycium barbarum L. from the Qaidam basin (QLBSO) in a UV-induced skin photodamage model in BALB/c mice, exploring potential mechanisms by analyzing the skin microbiota and metabolites using 16S rDNA sequencing and metabolomics. The results showed that QLBSO effectively alleviated UV-induced histopathological changes in mouse skin. It also significantly increased the activity of superoxide dismutase (SOD) and catalase (CAT) in UV-damaged skin tissue, while reducing levels of inflammatory cytokines, including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β), as well as matrix metalloproteinases-1 (MMP-1) and MMP-3. Omics analysis revealed that QLBSO successfully restored the balance of the skin microbiota and corrected disruptions in amino acid metabolism caused by UV exposure. Notably, Firmicutes_A and Kineothrix, along with cysteine, cystine, glycine, arginine, proline, and choline, were identified as key microbial species and metabolites responsive to QLBSO’s prophylactic and therapeutic effects. In conclusion, QLBSO likely protects against UV-induced skin photodamage by modulating the skin microbiota and amino acid metabolism, providing a scientific foundation for its potential use in skin health protection. Full article