Search Results (527)

Phage-encoded Shiga toxin (Stx) released by Shiga toxin-producing E. coli (STEC) can kill multiple eukaryotic bacterial predators, including Acanthamoeba castellanii, Tetrahymena thermophila and Caenorhabditis elegans. However, the impact of Stx type, Stx amount, and the serogroup of the E. coli on the effectiveness of this exotoxin are poorly understood. These factors impact the severity of Stx-mediated disease in humans and therefore, by studying their role in modulating predator–prey interactions, we may gain insight into how these virulence factors evolved to contribute to human pathogenicity. Herein, we investigated the effects of these factors on predator killing by measuring the efficiency with which five different hemolytic uremic syndrome (HUS)-causing STEC strains consume and/or kill A. castellanii and C. elegans. These strains express various combinations of Stx types and amounts and O-antigens. We found that variations in Stx types and amounts significantly affect the ability of a given bacterial strain to kill predator A. castellanii and C. elegans, with higher Stx1 titers (HUSEC 31 vs. 19) and the presence of Stx2 alone (HUSEC 20) correlating with significantly greater predator killing. These attributes also affect STEC pathogenicity in humans, suggesting that ecological selective pressures for anti-predator defense inadvertently drive the evolution of strains with higher virulence potential in humans. Full article

Malaria, caused by Plasmodium parasites, remains a global health crisis, necessitating novel therapeutic strategies targeting host–parasite interactions. During liver-stage infection, parasites exploit host vesicular trafficking machinery, particularly SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins that mediate membrane fusion. Using a CRISPR/Cas9 knockout system in HeLa cells combined with advanced microscopy of Plasmodium berghei-infected HeLa cells, we identified specific endolysosomal SNAREs including Vesicle-Associated Membrane Protein 7 (VAMP7), Vesicle-Associated Membrane Protein 8 (VAMP8), Vesicle Transport Through Interaction With T-SNAREs 1B (Vti1B), and Syntaxin 7 (Stx7) to be recruited to the parasitophorous vacuole membrane (PVM) with distinct temporal profiles. This demonstrates the parasite’s precise manipulation of host endolysosomal trafficking pathways. VAMP7 and Vti1B were localized to the PVM within 30 min post-infection, suggesting potential roles during invasion, while VAMP8 and Stx7 appeared later around 24 h post infection (hpi), coinciding with increased nutrient acquisition. Single gene deletions showed minimal impact, but combinatorial knockouts (KO) revealed critical redundancy. VAMP7-VAMP8 as well as VAMP7–Vti1B double KO significantly reduced parasite infection and growth, with Vti1B playing a dominant role. Triple KO phenotypes mirrored VAMP7-Vti1B disruption, underscoring Vti1B’s dominant role. SNARE depletion also impaired the lysosome–PVM association and LAMP1 positive vesicle recruitment. Our findings indicate Plasmodium hijacks a coordinated host SNARE network to fuse lysosomes with the PVM for nutrient uptake. Targeting Vti1B-containing complexes disrupts this pathway without host cell toxicity, offering a promising host-directed antimalarial approach. Full article

Bacterial toxins, such as Staphylococcal Enterotoxin B (SEB) and Shiga Toxins (STX1, STX2), pose severe public health risks and significant biological threats, demanding rapid and precise qPCR detection. This study reports the initial stages of standardization for uniplex qPCR components, serving as a foundational step toward a future multiplex detection system. The annealing temperature was successfully optimized for the stx1, seb, and 16S rRNA targets, showing high consistency in Cq values and fluorescence intensities at 58.4 °C. The optimized primer ratios ensure maximum amplification efficiency while minimizing potential molecular competition. These optimized assays provide a robust foundation for the multiplex qPCR platform. Once fully validated, this protocol will enhance timely and effective responses, as well as improve preparedness and readiness within the Brazilian biodefense system. Full article

Multidrug-resistant Escherichia coli (MDR-E. coli) poses a serious threat in foodborne infections, highlighting an urgent need for novel antimicrobial strategies. Natural plant-derived compounds, particularly flavonoids, have gained attention for their potential as alternative antimicrobial agents. This study aimed to evaluate the antibacterial efficacy and underlying mechanisms of luteolin (LUT), a dietary flavonoid, against MDR-E. coli, and to assess its immunomodulatory and microbiota-regulatory effects in vivo. (1) Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays were performed. (2) Biofilm formation, ATP synthesis, and alkaline phosphatase (AKP) leakage were measured. (3) Gene expression of resistance (tolC, ant(3″)-Ia) and virulence (fliC, K99, stx1) factors was analyzed via RT-PCR. (4) Network pharmacology and molecular docking identified key targets and pathways. (5) In vivo effects on intestinal pathology, inflammatory cytokines (IL-1β, IL-6, TNF-α), and gut microbiota composition were examined. The results show that (1) LUT exhibited potent antibacterial activity against MDR-E. coli (MIC = 1 mg/mL, MBC = 2 mg/mL). (2) It significantly inhibited biofilm formation, disrupted bacterial cell integrity, and suppressed ATP synthesis. (3) Expression of key resistance and virulence genes was downregulated. (4) In vivo, LUT alleviated intestinal inflammation, reduced pro-inflammatory cytokine levels, and restored gut microbial diversity, notably enriching beneficial bacteria (E. faecalis). (5) Network analysis revealed involvement of interleukin signaling pathways. LUT demonstrates dual antibacterial and immunomodulatory effects against MDR-E. coli through direct microbial inhibition and host immune regulation. It represents a promising food-compatible alternative to conventional antibiotics, with potential applications in controlling multidrug-resistant infections in the food chain. Further clinical studies are warranted to validate its efficacy and safety in humans. Full article

Laser scanners based on the Simultaneous Localization and Mapping (SLAM) principle generate extremely dense point clouds burdened with a high level of surface noise arising from random measurement errors and repeated scanning of identical regions. This increases data volume and complicates subsequent processing. The present study introduces four novel noise filtering and subsampling algorithms that selectively preserve the points closest to the true surface. Each algorithm assigns a filtering characteristic to individual points based either on their distance from a locally estimated (planar or quadratic) surface or on the degree of local eccentricity in the spherical neighborhood of the point. The proposed methods were tested on point clouds acquired using three SLAM scanners (Emesent Hovermap ST-X, FARO Orbis, and ZEB Horizon) in three different scenes with reference data acquired by a static terrestrial scanner Leica P40. All four proposed methods effectively reduced surface noise and data volume (improving the RMSDs by 45.4–75.8% compared to the original cloud after thinning to 10% of cloud size). This clearly outperformed the standard subsampling tools, namely random subsampling (RMSD remained constant after subsampling), octree, or spatial subsampling (worsening of RMSDs with increasing subsampling). The most reliable surface noise removal in point clouds dominated by planar surfaces (building interior with planar walls) was achieved using the method based on local plane fitting. In contrast, the use of a quadratic surface proved more effective for uneven or rugged surfaces. Full article

Background/Objectives: In food-producing animal (FPA) environments, healthy animals can act as reservoirs of potentially pathogenic Escherichia coli, which can be transmitted through the food chain to humans. This study aimed to evaluate cloacal E. coli in healthy Sicilian lambs subjected to an experimental feeding regimen by assessing bacterial levels, antimicrobial resistance, virulence traits, and the clonal relationships, as well as the impact of a pistachio skin as an agro-industrial by-product supplement during a 58-day feeding trial. Methods: A total of 295 E. coli isolates from the control (CTRL) and treatment (Treated) groups at initial time (T0) and final time (T1) were phenotypically and genotypically characterized using Kirby–Bauer antimicrobial testing, multiplex PCR for virulence genes, and PFGE for clonal analysis. Results: The feeding regimen did not significantly influence the prevalence, abundance, or virulence of the E. coli isolates. Shiga toxin-producing E. coli (STEC) were the most common pathotype, mainly carrying the stx1 gene, while the Enteroinvasive (EIEC) type was detected only sporadically. Enteropathogenic E. coli (EPEC) predominated at T0, while enteroaggregative E. coli (EAEC) at T1, and enterotoxigenic E. coli (ETEC), initially prevalent in Treated samples, disappeared by T1. Antimicrobial resistance profiles varied among isolates, with the highest resistance observed in the CTRL group. However, both groups exhibited high resistance to streptomycin, and 9% of CTRL isolates were multidrug resistant. A notable reduction in overall resistance rates, especially in the Treated group, was observed, indicating a dietary effect on the E. coli resistome. PFGE genotyping showed high genetic diversity, with resistance traits more frequently detected than virulence factors. Conclusions: This study highlights that healthy lambs serve as reservoirs for potentially human-pathogenic E. coli and suggests that dietary regimes could effectively reduce antibiotic resistance. Full article

Background: Shiga toxin (Stx), produced by enterohemorrhagic Escherichia coli (EHEC), is a highly potent exotoxin responsible for severe complications such as hemolytic uremic syndrome (HUS). Among its isoforms, Stx2 exhibits stronger cytotoxicity and poses greater clinical risk, yet no effective therapy currently exists. Methods: In this study, two human monoclonal antibodies, YG12-1 and YG12-2, were identified from a phage display library and systematically characterized using an integrated modeling–validation workflow. Results: Structural modeling with ImmuneBuilder and Rosetta revealed that YG12-2 possessed a longer CDRH3 topology, more short-range hydrogen bonds, and stronger electrostatic complementarity, corresponding to lower binding energy and higher apparent affinity in ELISA and SPR. Although YG12-2 had a better affinity, YG12-1 shows better protective activity in a murine model of acute peritoneal infection. This paradox highlights a non-linear relationship between structural affinity and biological efficacy, emphasizing the importance of functional epitope accessibility and pharmacokinetic behavior in determining neutralization outcomes. Conclusions: Overall, these results indicated that targeting Stx2 with YG12-1 and YG12-2 could serve as a promising protective strategy against E. coli O157:H7 infection. Full article

RNA dysregulation mediated by aberrant RNA-binding proteins (RBPs) is closely associated with tumorigenesis. However, the tumorigenic mechanisms of each RBP remained unclear. In this study, we demonstrate that downregulation of Splicing factor 3A1 (SF3A1) markedly suppressed the proliferation of colorectal cancer (CRC) cells, with minimal cytotoxicity observed in non-cancerous epithelial cells. The tumor-promoting function of SF3A1 was further validated in an HCT116 xenograft mouse model. Multiple apoptosis assays—including TdT-mediated dUTP nick end labeling (TUNEL) staining, poly-ADP-ribose polymerase (PARP) immunoblotting, and caspase-3/7 activity measurements—showed that SF3A1 inhibited apoptotic signaling in CRC cells. Transcriptome analysis, combined with RNA-immunoprecipitation (RIP), identified Syntaxin 12 (STX12) as a downstream effector of SF3A1. Knockdown of STX12 induced apoptosis in CRC cells but had no effect on the viability of non-cancerous HCEC-1CT epithelial cells. Furthermore, STX12 mRNA levels were significantly reduced following SF3A1 knockdown, indicating that SF3A1-mediated stabilization of STX12 contributes to apoptosis resistance in CRC cells. Collectively, our findings establish that SF3A1 promotes CRC progression by stabilizing STX12 mRNA and selectively inhibiting apoptosis in malignant cells, thereby identifying the SF3A1–STX12 regulatory axis as a novel and selective therapeutic target for CRC. Full article

An increasing number of stroke survivors are burdened by persistent disabilities, requiring long-term rehabilitation. However, the extent of functional gain is highly variable, severely impairing patients’ quality of life. This variability highlights a critical gap in current prognostic tools, which rely primarily on clinical and neuroimaging data. The aim of this review is to synthesize the current literature on serum biomarkers in stroke survivors and to evaluate their prognostic value for rehabilitation outcomes. Our synthesis indicates that biomarkers reflecting distinct pathophysiological processes are emerging as key prognostic indicators. Markers of inflammation such as Tumor Necrosis Factor-alpha (TNF-α), Interleukin-6 (IL-6), and Interleukin-1 beta (IL-1β), and neuro-glial injury, including S100 Calcium-Binding Protein B (S100B), Neuron-Specific Enolase (NSE), Glial Fibrillary Acidic Protein (GFAP), and Neurofilament Light Chain (NfL), are consistently associated with poorer functional outcomes. Conversely, markers of neuroplasticity, such as Brain-Derived Neurotrophic Factor (BDNF) and Insulin-like Growth Factor-1 (IGF-1), serve as potential indicators of recovery potential, although their predictive accuracy remains inconsistent across studies. Furthermore, emerging biomarkers of synaptic activity, such as Syntaxin-1a (STX1A) and Synaptosomal-Associated Protein, 25kDa (SNAP-25), and neuromuscular junction integrity, such as C-terminal Agrin Fragment (CAF), offer novel insights into brain–periphery communication, though their clinical utility is still under investigation. While promising, the translation of these biomarkers into clinical practice is hindered by methodological limitations, including assay heterogeneity and lack of large-scale validation. Future standardization of these molecular signatures is a critical step toward implementing precision medicine in stroke rehabilitation. Full article

Shiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen of public health concern, requiring a One Health approach to clarify its transmission and distribution. However, its prevalence and genomic characteristics in livestock and companion animals remain underexplored in low-income countries. We investigated prevalence and genomic features of STEC in animals in western Ghana, representing the first genomic report of STEC in Ghana. Fecal samples (97) were collected from goats (n = 33), sheep (n = 33), dogs (n = 30), and a cat (n = 1), with STEC detected in 12.1% of goats and sheep samples. Whole-genome sequencing identified serotypes O38:H26, O43:H2, and O157:H7. stx1c and stx2b genes were detected in O38:H26 and O43:H2, whereas stx2c and key virulence genes (chuA, eae, esp, nle, tir, and toxB) were exclusively found in O157:H7. Phylogenetic analysis revealed that O38:H26 isolates form a cluster closely related to clinical strains from the UK. O43:H2 isolates exhibited diverse stx profiles, linking animal, environmental, and clinical strains from North America and the UK. O157:H7 isolates were genetically similar to European clinical and food-derived strains, suggesting that goats and sheep are important STEC reservoirs in Ghana, offering data for public health risk assessment and effective One Health-based control strategies. Full article

Saxitoxin (STX) is one of the most potent marine neurotoxins, produced by several species of freshwater cyanobacteria and marine dinoflagellates. Although omics-based approaches have advanced our understanding of STX biosynthesis in recent decades, the origin, regulation, and ecological drivers of STX in dinoflagellates remain poorly resolved. Specifically, dinoflagellate STX biosynthetic genes (sxt) are extremely fragmented, inconsistently expressed, and unevenly distributed between toxic and non-toxic taxa. Environmental studies further report inconsistent relationships between abiotic factors and STX production, suggesting regulation across multiple genomic, transcriptional, post-transcriptional, and epigenetic levels. These gaps prevent a comprehensive understanding of STX biosynthesis in dinoflagellates and limit the development of accurate predictive models for harmful algal blooms (HABs) and paralytic shellfish poisoning (PSP). Artificial intelligence (AI), including machine learning and deep learning, offers new opportunities in ecological pattern recognition, molecular annotation, and data-driven prediction. This review explores the current state of knowledge and persistent knowledge gaps in dinoflagellate STX research and proposes an AI-integrated multi-omics framework highlighting recommended models for sxt gene identification (e.g., DeepFRI, ProtTrans, ESM-2), evolutionary reconstruction (e.g., PhyloGAN, GNN, PhyloVAE, NeuralNJ), molecular regulation (e.g., MOFA+, LSTM, GRU, DeepMF), and toxin prediction (e.g., XGBoost, LightGBM, LSTM, ConvLSTM). By integrating AI with diverse biological datasets, this novel framework outlines how AI can advance fundamental understanding of STX biosynthesis and inform future applications in HAB monitoring, seafood safety, and PSP risk management in aquaculture and fisheries. Full article

Objective: This study aims to investigate the functional role of lncRNA STX17-DT, which was previously found to be upregulated in peripheral blood mononuclear cells (PBMCs) of PBC patients, by examining its impact on gene expression and cellular behavior in a human monocyte model. Methods: STX17-DT was overexpressed in THP-1 cells, which was assessed via plasmid transfection. Transcriptomic changes were analyzed by RNA sequencing, followed by comprehensive bioinformatics analyses including differential expression, functional enrichment, transcription factor network, and protein–protein interaction (PPI) analysis. Functional validation was performed using CCK-8 and TUNEL assays to assess proliferation and apoptosis, respectively. Results: Overexpression of STX17-DT led to 1973 differentially expressed genes (DEGs), with 1201 upregulated and 772 downregulated. Key upregulated genes included interferon-stimulated genes (e.g., interferon induced protein 44 like (IFI44L), interferon induced protein 44 (IFI44), guanylate binding protein 1(GBP1)) and chemokines (CCL4, CCL8). Upregulated DEGs were significantly enriched in immune-related pathways such as NF-κB signaling, Toll-like receptor signaling, TNF signaling, and cytokine–cytokine receptor interaction. Downregulated genes were involved in metabolic and signaling pathways such as PI3K–Akt, cAMP, and butanoate metabolism. Transcription factor analysis revealed significant alterations in regulators like Yes1 associated transcriptional regulator(YAP1), nuclear receptor subfamily 4 group A member 1(NR4A1), and MAF bZIP transcription factor B(MAFB). PPI network analysis suggested TNF, TLR4, TLR6, and STAT2 as central hubs. Functionally, STX17-DT overexpression enhanced THP-1 cell proliferation and significantly reduced apoptosis. Conclusions: STX17-DT promoted a pro-inflammatory transcriptomic profile and enhanced monocyte survival in our study, suggesting a potential role in PBC immunopathology. It may represent a potential biomarker and therapeutic target, particularly for patients with advanced disease or suboptimal response to ursodeoxycholic acid. Further studies in primary cells, animal models, and histological samples are warranted to validate its role in PBC pathogenesis. Full article

The Isles of Scilly are an archipelago of islands in the far southwest of the UK which contain numerous beds of wild bivalve molluscs which are recreationally harvested for local consumption. However, the islands have never previously been assessed for the presence of harmful algae and their shellfish toxin metabolites which can cause serious human health impacts. This study sought to address these knowledge gaps through the analysis of seawater and shellfish tissues for microalgae and toxins utilizing portable and lab-based microscopy, nanopore sequencing, chemical analysis and immunoassay kits. The study design was affected by the national COVID-19 lockdown which enforced implementation of citizen-led sampling and in-field microscopy. Microscopy and sequencing approaches led to the confirmation of multiple HAB species of concern, including those potentially responsible for production of neurotoxic and diarrhetic shellfish toxins. A portable microscope was successfully utilized in the field for recognition of microalgae and for early warning of potential shellfish toxicity events. Chemical analysis of cockle, clam and mussel samples confirmed the detection of paralytic, diarrhetic and amnesic shellfish toxins, with an unusual okadaic acid group toxin profile reaching a maximum toxicity of approximately half the regulatory limit as defined by EU law. The Sensoreal Alert Lateral Flow Assay was used to screen and highlight samples containing higher concentrations of DSP toxins. Furthermore, Tetrodotoxin was detected for the first time in the UK in cockle and grooved carpet shells. Multiple saxitoxin analogues were also detected in two echinoderm species, with this providing the first ever report of paralytic shellfish toxins in the spiny starfish, Marthasterias glacialis. The toxin profiles in the two species varied significantly with a dominance of GTX4 in Luidia ciliaris as opposed to a dominance of STX in Marthasterias glacialis. Overall, the study showed that a multi-method assessment of a previously unexplored region within the UK territory contained microalgae and toxins of concern to human health, and that a citizen-led programme could be instigated using portable microscopy and rapid toxin testing to assess the early warning for potentially harmful microalgae and toxins in the region, with confirmatory analysis being conducted to establish actual levels of risk for local consumers of seafood. Full article

Shiga toxin-producing Escherichia coli (STEC) is a major foodborne pathogen, responsible for severe gastrointestinal disease and hemolytic uremic syndrome (HUS). Here, we report Click Detect, a novel diagnostic platform that leverages click display to efficiently produce sensing probes for sandwich-style antigen detection. Click display is an in vitro protein display technology that generates uniform and covalently linked protein–cDNA conjugates in a simple one-pot reaction format within 2 h. The captured sensing probe can be quantified by standard nucleic acid amplification assays. Using click displayed DARPin (D_#20) as the sensing probe and a high-affinity nanobody (N_G1) as the capture reagent, Click Detect reliably detected Shiga toxin 2 (Stx2) at 600 fM by quantitative PCR (qPCR) and 6 pM by loop-mediated isothermal amplification (LAMP). The assay maintained comparable sensitivity in matrices containing up to 40% public swimming pool water or lettuce extract, highlighting robustness for real-world surveillance applications. Key advantages of Click Detect include simple, rapid, and cost-effective (~USD 0.04 per assay) sensing probe preparation, as well as a versatile plug-and-play probe format for detecting other targets. We believe that Click Detect has great potential as a novel sensing platform for food/environmental monitoring and point-of-care diagnostics, with potentially broad applicability to other toxins and protein targets. Full article

The pond slider (Trachemys scripta) is native to the southeastern United States but has been introduced all around the world, including to the Canary Islands (Spain), along with other less-common exotic freshwater turtles such as Graptemys pseudogeographica, Mauremys spp., and Pseudemys peninsularis. The aim of this study was to determine the presence of pathogenic bacteria in these animals and to evaluate the associated health risks for humans and local fauna. For this purpose, cloacal samples from 42 specimens collected on the islands of Tenerife and Gran Canaria (Canary Islands) were analyzed for potentially zoonotic bacteria using selective culture media and PCR. Non-tuberculous mycobacteria were the most isolated pathogen (57.9%), followed by Yersinia enterocolitica (42.1%) and Escherichia coli carrying stx and/or eae genes (33.3%). Salmonella spp. was detected in 31.0% of the chelonians, identifying Salmonella Typhi and Salmonella Typhimurium serotypes. Staphylococcus spp. showed a prevalence of 21%, mainly Staphylococcus aureus along with one antibiotic-resistant Staphylococcus hominis isolate. Pseudomonas spp. were found in 10.1% of samples, although only one isolate corresponded to Pseudomonas aeruginosa. Campylobacter spp. and Vibrio spp. were detected at low frequencies (<10%), and Listeria monocytogenes was not identified. Overall, the results indicate that aquatic turtle populations in the Canary Islands pose notable health risks, especially for animal handlers and people with compromised immune systems. Full article