Search Results (872)

Radiographic imaging remains a cornerstone of diagnostic practice. However, accurate interpretation faces challenges from subtle visual signatures, anatomical variability, and inter-observer inconsistency. Conventional deep learning approaches, such as convolutional neural networks and vision transformers, deliver strong predictive performance but often lack anatomical grounding and interpretability, limiting their trustworthiness in imaging applications. To address these challenges, we present SpineNeuroSym, a neuro-geometric imaging framework that unifies geometry-aware learning and symbolic reasoning for explainable medical image analysis. The framework integrates weakly supervised keypoint and region-of-interest discovery, a dual-stream graph–transformer backbone, and a Differentiable Radiographic Geometry Module (dRGM) that computes clinically relevant indices (e.g., slip ratio, disc asymmetry, sacroiliac spacing, and curvature measures). A Neuro-Symbolic Constraint Layer (NSCL) enforces monotonic logic in image-derived predictions, while a Counterfactual Geometry Diffusion (CGD) module generates rare imaging phenotypes and provides diagnostic auditing through counterfactual validation. Evaluated on a comprehensive dataset of 1613 spinal radiographs from Sunpasitthiprasong Hospital encompassing six diagnostic categories—spondylolisthesis (n = 496), infection (n = 322), spondyloarthropathy (n = 275), normal cervical (n = 192), normal thoracic (n = 70), and normal lumbar spine (n = 258)—SpineNeuroSym achieved 89.4% classification accuracy, a macro-F1 of 0.872, and an AUROC of 0.941, outperforming eight state-of-the-art imaging baselines. These results highlight how integrating neuro-geometric modeling, symbolic constraints, and counterfactual validation advances explainable, trustworthy, and reproducible medical imaging AI, establishing a pathway toward transparent image analysis systems. Full article

Understanding antimicrobial resistance (AMR) within a One Health framework requires examining how human–animal–environment interactions shape bacterial populations, and captive wildlife offers a unique context to explore these dynamics. This study aimed to characterise the phenotypic resistance and virulence profiles of Escherichia coli isolated from faecal samples of captive non-domestic felids housed in a wildlife sanctuary in the United Kingdom and evaluate the influence of captive conditions in E. coli traits. A total of 41 faecal samples were collected from 36 animals representing 11 non-domestic felid species, from which it was possible to obtain 108 E. coli isolates identified using IMViC testing. The isolates were characterised regarding their susceptibility to 12 antibiotics by disc diffusion and screened for the phenotypic expression of six virulence factors, including protease, DNase, gelatinase, lecithinase, haemolysins, and biofilm formation. The highest resistance rates were observed for tetracycline (19.4%) and ampicillin (10.2%), while isolates presented complete susceptibility regarding half of the tested antibiotics. Also, 9.3% of the isolates presented a multidrug-resistant profile. Biofilm formation was the only virulence factor expressed by the isolates under study (8.3%). Significant associations were detected between resistance outcomes and levels of human proximity and enclosure type. These findings suggest that captivity-related factors may influence AMR profiles in wild felids and highlight the importance of continued AMR surveillance and appropriate management practices to reduce selective pressures in captive wildlife. Full article

Underground hydrogen storage (UHS) in depleted oil and gas reservoirs is regarded as a highly promising subsurface option due to its large storage capacity. In such reservoirs, the pore structure provides the primary space for hydrogen storage and governs matrix flow and diffusion. Tree-shaped fracture networks generated by hydraulic fracturing or cycling injection–production typically exhibit much higher transmissivity and serve as the dominant pathways. In this study, the geometry of multilevel branching fractures was parameterized, and two classes of tree-shaped fracture configurations were constructed, including point–line-type (PLTSF) and disc-shaped (DSTSF) networks. Analytical models were developed to evaluate the equivalent permeability of tree-shaped fracture networks with either elliptical or rectangular cross-sections. The Klinkenberg slip correction and a gas-type factor associated with molecular kinetic diameter were incorporated. The apparent equivalent permeability of hydrogen (k_app,H2) was quantified and compared with those of nitrogen and methane under identical conditions. The main findings were as follows: (1) the fracture width ratio (β) was identified as the primary factor controlling network conductivity, while the height ratio (α) amplified or attenuated this effect at a given β; (2) as the main-fracture aspect ratio, the branching order (n) or branching angle (θ) increased, the rectangular cross-sections were more favorable for maintaining higher permeability compared to the elliptical cross-section; (3) under typical operating pressures of 5–30 MPa, the apparent permeability of hydrogen was approximately 2–9% higher than that of methane and nitrogen; and (4) by introducing the fracture volume fraction, the REV-scale equivalent-permeability expression was derived for fractured rock masses containing tree-shaped fracture networks. The proposed framework provides a theoretical basis and parametric support for quantifying fracture flow capacity for UHS in depleted reservoirs. Full article

Streptococcus agalactiae is a major cause of bovine mastitis, which affects the quality and yield of milk. The main strategy for controlling this pathogen on dairy farms is the use of antibiotics. This study investigated the clonality, serotype distribution, antimicrobial susceptibility, and presence of resistance and virulence genes in 46 S. agalactiae isolates obtained from raw bovine milk in northeastern Brazil. Capsular types were determined using multiplex PCR and antibiotic susceptibility profiles were determined using disc diffusion or the gradient strip method. Clonal diversity was evaluated via pulsed-field gel electrophoresis. Eight isolates were sequenced using short- and long-read methods. There was high overall genetic diversity, whereas the resistance and virulence profiles were largely homogeneous within herds. Tetracycline and macrolide resistance was frequent and mediated by tetO and ermB and less frequently by tetM. Genome analysis demonstrated that resistance genes are present in mobile genetic elements that are also present in human isolates, and phylogenomic analyses identified ST-103 as the predominant and multi-host-adapted lineage, whereas ST-91 clustered with the bovine-adapted lineage. These findings expand the molecular epidemiology of S. agalactiae in dairy farms of a region in northeast Brazil and highlight the importance of surveillance strategies for guiding mastitis control and mitigating the spread of antimicrobial resistance. Full article

Thorium carbide (${\mathrm{ThC}}_{2\pm x}$) nano-structured thin disc-like pellets were produced from thoria nanoparticles (${\mathrm{ThO}}_2$-NP) and multi-walled carbon nanotubes (MWCNT). These composites are to be studied as a target material candidate for radioactive ion beam (RIB) production via nuclear reactions upon impact with high-energy proton beams on a stack of solid pellets. The ${\mathrm{ThO}}_2$-NP precursor was produced via precipitation of thorium oxalate from a thorium nitrate solution with oxalic acid and subsequent hydrothermal oxidation of the oxalate, creating the thoria nanoparticles. The ${\mathrm{ThO}}_2$-NP were then mixed with MWCNT in isopropyl alcohol and sonicated by two different methods to create a nanoparticle dispersion. This dispersion was then heated under medium vacuum to evaporate the solvent; the resulting powder was pressed into pellets and taken to an inert-atmosphere oven, where it was heated to 1650 °C and carbothermally reduced to ${\mathrm{ThC}}_{2\pm x}$. The resulting pellets were characterized via XRD, SEM-EDS, and Raman spectroscopy. The resulting thorium pellets exhibited, at most, trace levels of the oxide precursor. Furthermore, the nanotube structures were still present in the final product and are expected to contribute positively towards faster radioisotope release times by lowering isotope diffusion times, which is required for the efficient extraction of the shortest-lived (<1 s half-life) radioisotopes. Full article

Antimicrobial resistance (AMR) is a major global health concern, which complicates treatment of microbial infections and wounds. Conventional therapies are no longer effective against drug resistant microbes; hence, novel antimicrobial approaches are urgently required. Silver nanoparticles (AgNPs) offer stronger antimicrobial activity, and in situ synthesis improves stability, uniformity, cost efficiency, and bioactivity while minimising contamination. These features make AgNPs well-suited for incorporation into textiles and wound dressings. Red wine extract (RW-E), rich in antioxidant and anti-inflammatory compounds was used to hydrothermally synthesise RW-AgNPs and RW-AgNPs-loaded on cotton (RWALC) by optimising pH and RW-E concentration. Characterisation was performed using UV–Vis spectroscopy, dynamic light scattering (DLS), and High Resolution and Scanning electron microscopy (HR-TEM and SEM). Antibacterial activities were evaluated against human pathogens through agar disc diffusion assay for RWALC and microdilution assay for RW-AgNPs. RWALC showed higher potency against both Gram-negative and Gram-positive bacteria, with inhibition zones of 12.33 ± 1.15 to 23.5 ± 5.15 mm, that surpassed those of ciprofloxacin (10 ± 3 to 19.17 ± 1.39 mm at 10 μg/mL). RW-AgNPs exhibited low minimum inhibitory concentrations (MIC: 0.195–3.125 μg/mL) and minimum bactericidal concentrations (MBC: 0.78–6.25 μg/mL). Preincubation with β-mercaptoethanol (β-ME) inhibited the antibacterial activity of RWALC, suggesting that thiolated molecules are involved in AgNPs-mediated effects. This study demonstrated that green-synthesised RW-AgNPs, incorporated in situ into cotton, conferred strong antibacterial properties, warranting further investigation into their mechanisms of action. Full article

Vancomycin-resistant Enterococci (VRE) are established nosocomial pathogens; however, vancomycin-dependent Enterococci (VDE) represent a rare and underrecognized phenomenon. These organisms paradoxically require vancomycin for growth due to mutations in cell wall precursor synthesis. Limited awareness and significant diagnostic challenges associated with VDE can lead to delayed recognition and treatment failure. We report a case of vancomycin-dependent Enterococcus faecium isolated from a liver transplant recipient receiving oral vancomycin prophylaxis for recurrent Clostridioides difficile infection. The isolate failed to grow on standard media but exhibited robust growth on vancomycin-supplemented agar, confirmed by vancomycin disc diffusion testing and PCR detection of the vanB gene. Additionally, we reviewed four further VDE cases identified over a two-year period in our tertiary care microbiology laboratory. All patients originated from complex care settings, had significant comorbidities, and had received prolonged glycopeptide therapy. We summarize the clinical features, diagnostic findings, and microbiological challenges encountered across this case series. This series documents the first reported Canadian case of VDE and highlights the critical need for clinical vigilance and diagnostic suspicion in high-risk patients with prior enterococcal colonization and ongoing glycopeptide exposure. Laboratory findings such as failure to grow on blood agar coupled with growth around vancomycin discs should prompt specific evaluation for VDE. Our findings reinforce the necessity for targeted antimicrobial stewardship and infection prevention strategies and underscore the remarkable evolutionary adaptability of Enterococci under sustained antimicrobial pressure. Full article

Introduction: Haemolytic Escherichia coli (E. coli) is commonly associated with enteric disease in pigs and is frequently used as a phenotypic marker for enterotoxigenic E. coli (ETEC). This study aimed to characterise the resistance and virulence profiles of haemolytic E. coli isolated from Colombian pig farms. Methods: A total of 367 faecal samples from sows and pigs across all production stages were collected and analysed for the presence of haemolytic E. coli. Resistance and virulence genes associated with ETEC was detected by multiplex PCR, and antimicrobial susceptibility profiles were determined using broth microdilution and disc diffusion. Results: Haemolytic E. coli were identified in 40.3% of samples (n = 148 non-duplicate isolates), with the highest prevalence observed in growing piglets (47.1%). ETEC occurred in 5.4% of isolates. All isolates exhibited resistance to at least three antimicrobial classes (MDR), with high levels of resistance to tetracycline (98.0%), neomycin (97.3%), chloramphenicol (95.9%), sulfamethoxazole (93.9%), trimethoprim (91.9%), ampicillin (91.9%), nalidixic acid (82.4%), and ciprofloxacin (79.7%). Colistin resistance was observed in 5.4% of isolates, mediated by mcr1 or mcr3, while cefotaxime resistance (8.8%) was extensively associated with blaCTX-M. Conclusions: These findings reveal a concerning burden of MDR E. coli in Colombia’s pig-producing regions and indicate that haemolysis alone is a poor indicator of ETEC. Integrating farm-level antimicrobial use data with genomic analyses will be essential to identify drivers of AMR and guide effective stewardship in the Colombian pig industry. Full article

Background/Objectives: Although children’s playgrounds foster physical, cognitive and emotional health, sandpits can harbour antibiotic-resistant bacteria, representing a health concern for kids. Therefore, this point prevalence study investigated the presence and antimicrobial resistance of Escherichia coli in sandpits at four schools in Durban to ascertain the potential risk to schoolchildren and inform school authorities of the need to prevent such occurrences. Methods: Twenty samples were collected from schools on a single day. E. coli was isolated using colilert-18^® and confirmed using PCR. Antibiotic susceptibility testing was performed against 19 antibiotics using the disc diffusion method and Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: E. coli was detected in 2/4 schools (50%), yielding 100 pure isolates. Of these, 71% (31 Site B and 40 Site C isolates) were resistant to at least one of the antibiotics tested, displaying 36 antibiograms. The highest resistance was to CFX (n = 40), and the lowest was to AMK and MEM (n = 1). All isolates were susceptible to CIP, CHL, GEN and TZP. At Site B, the highest resistance was against CFX (n = 16) and the lowest against AMK, CTX and NAL (n = 1). The highest resistance at Site C was against TET (n = 26), and the lowest against ATH and AUG (n = 1). Twenty isolates (20%) were multidrug-resistant, displaying resistance to at least one antibiotic from 3 classes. Conclusions: These results show that children with poor hygiene practices could get sick from playing in sandpits. Schools must change their sand regularly and ensure that sandpits are constantly exposed to the sun. Full article

Peri-implant infections pose a significant challenge in dental implantology. This study aimed to develop and characterize a chitosan–vancomycin coating for titanium surfaces, focusing on drug loading, release kinetics, antimicrobial performance, and cytocompatibility. Grade 4 titanium discs were coated with a chitosan film using the dip-coating technique and subsequently loaded with vancomycin through immersion in an aqueous solution. Coating morphology was examined by scanning electron microscopy (SEM). Vancomycin loading was quantified by spectrophotometry, and release kinetics were monitored over 144 h (6-day). Antimicrobial activity was assessed through agar diffusion assays against Staphylococcus aureus. Cytocompatibility was evaluated using human mesenchymal stem cells (hMSCs), whose metabolic activity, adhesion, and morphology were assessed over a 19-day culture period by resazurin assay and SEM. SEM analysis revealed a uniformly distributed, smooth, and crack-free chitosan film, which remained stable after drug loading. The coating exhibited a biphasic release profile, characterized by an initial burst followed by sustained release over six days, which maintained antimicrobial activity, as confirmed by inhibition zones. hMSCs adhered and proliferated on the coated surfaces, displaying normal morphology despite a transient reduction in metabolic activity on vancomycin-containing films. These findings support the potential of chitosan–vancomycin coatings as localized antimicrobial strategies for implant applications, warranting further in vivo and mechanical evaluations. Full article

In the present study, Dipteryx odorata seeds (tonka beans) were extracted via the Soxhlet method to acquire ethanolic (TBSE) and hexane (TBSH) extracts. Both extracts were characterized using Gas Chromatography–Mass Spectrometry (GC-MS). The antimicrobial activity was evaluated against two Gram-positive (Bacillus licheniformis, Staphylococcus epidermidis) and two Gram-negative (Escherichia coli, Pseudomonas aeruginosa) human pathogens using the disc diffusion test (DDT), followed by the determination of Minimum Inhibitory Concentrations (MIC). The Cytokinesis-Block Micronucleus (CBMN) assay was applied in human lymphocytes (0.1, 0.2, 0.5 µL/mL), to investigate the cyto-genotoxic activity of both extracts, while their antigenotoxic potential was evaluated against mitomycin C (MMC) (0.5 μg/mL). Coumarin was the major constituent in both extracts. TBSE exhibited remarkable antimicrobial activity, whereas TBSH was not equally potent. Cytotoxicity was reported for higher doses, while no genotoxicity was observed, except for 0.2 µL/mL for TBSE. A considerable antigenotoxic activity was shown by the lowest dose of TBSE, which was not present at the two highest concentrations. However, TBSH did not diminish the MMC mediated genotoxicity, while at the same time led to an increase in genotoxic potency. To our knowledge, this is the first comprehensive evaluation of the cyto-genotoxic and antigenotoxic profiles of tonka bean extracts. Full article

The skin of turtles, particularly aquatic species, can harbor a diverse range of bacteria, including Citrobacter species, which are recognized as causative agents of Septicemic Cutaneous Ulcerative Disease. Consequently, turtles may act as reservoirs of pathogenic and multidrug-resistant bacteria, posing a potential public health concern. This case-based study investigated the presence of Citrobacter spp. in a loggerhead sea turtle (Caretta caretta) housed at the Livorno Aquarium, Italy. Nine swabs were collected from skin lesions (plastron, carapace, nuchal mass), the oral cavity, and the cloaca. The isolated strains were identified by MALDI-TOF MS and tested for their susceptibility to 12 antimicrobials, belonging to eight antimicrobial classes, by the disc diffusion method. Isolates were investigated genotypically for extended-spectrum-β-lactamase (ESBL) bla_CTX−M, bla_TEM, bla_SHV, bla_PER, and metallo-β-lactamase (MBL) bla_IMP, bla_OXA−48, bla_VIM, bla_NDM, bla_GES genes. Biofilm production ability was also evaluated. Fifteen Citrobacter spp. strains were recovered from the analyzed samples. Complete resistance was recorded for ampicillin, followed by high levels of resistance to imipenem, tetracycline and piperacillin-tazobactam. Worryingly, 86.7% were classified as multidrug-resistant. The most common ESBL-genotype combination was bla_SHV and bla_PER genes (60%), while the most frequently detected MBL gene was bla_NDM (46.7%), followed by bla_GES (40%). Most isolates were classified as weak biofilm producers (80%). The findings of this study demonstrate the presence of Citrobacter spp., an opportunistic pathogen, with a notable prevalence of multidrug-resistant strains carrying beta-lactamase-encoding genes, in a loggerhead sea turtle in Italy, across both lesioned and healthy anatomical sites. Full article

Cedrus atlantica wood tar (CAWT) is traditionally used as a medicinal product, especially in low- and middle-income countries. Despite its traditional use, scientific support for its efficacy remains limited. This study evaluated the biological properties of CAWT using an integrated approach that combined qualitative and quantitative phytochemical analysis, disc diffusion and microdilution tests for antimicrobial assays (disc diffusion and microdilution), antioxidant activity (DPPH and ferric-reducing power assays), in silico ADMET/toxicity, docking, and MD/MMGBSA and provided a balanced comparison with reference antioxidants. This study demonstrated that CAWT is rich in secondary metabolites linked to biological activity, including polyphenols (307.39 ± 58.45 mg GAE/g), tannins (124.42 ± 6.14 mg TAE/g), and flavonoids (15.62 ± 2.53 mg QE/g). For free radical scavenging, CAWT inhibited DPPH with an IC50 of 19.781 ± 2.51 µg/mL and showed ferric-reducing activity with an IC50 of 83.7 ± 2.88 µg/mL for its antimicrobial activity against Pseudomonas aeruginosa; inhibition zones reached 35.66 ± 0.58 mm. In silico analysis, Swiss ADMET and pkCSM predicted ≥94% intestinal absorption, no cytochrome P450 liabilities, and low acute toxicity for six dominant terpenoids. Docking pinpointed trans-cadina-1(6),4-diene and α/β-himachalene as high-affinity ligands of LasR and gyrase B (ΔG ≈ −8 kcal mol⁻¹). A 100 ns GROMACS run confirmed stable hydrophobic locking of the lead LasR complex (RMSD 0.22 nm), while MM/GBSA calculated a dispersion-dominated binding free energy of −37 kcal mol⁻¹. Overall, CAWT showed in vitro antioxidant activity (DPPH and ferric-reducing assays) and inhibitory effects in disc diffusion assays, while in silico predictions for major terpenoids suggested favorable oral absorption and low acute toxicity. However, chemical composition analysis and bio-guided fractionation are necessary to confirm the antimicrobial activity and to validate the compounds responsible for the observed effects. Full article

Background: This study investigated the phenotypic and genotypic antibiotic resistance profiles of 50 Lactic Acid Bacteria (LAB) strains—25 Lactiplantibacillus plantarum and 25 Lacticaseibacillus paracasei—isolated from traditional Sardinian fermented foods of animal origin. Methods: The sensitivity of the isolates to antibiotics such as β-lactams, tetracyclines, aminoglycosides, macrolides, phenicols, and glycopeptides was initially assessed using disc diffusion and minimum inhibitory concentration (MIC) tests. Subsequently, PCR analyses were performed on both genomic DNA and plasmid DNA to detect blaZ, tet(W), strA, aac(6′)-Ie–aph(2″)-Ia, and vanX genes associated with resistance to ampicillin, tetracycline, streptomycin, gentamicin, and vancomycin. Results: The analysis revealed that L. plantarum strains frequently carried the tet(W) gene on the chromosome and strA on plasmids, while vanX was detected in most strains as a chromosomal determinant. By contrast, L. paracasei strains exhibited a predominantly plasmid-mediated distribution of resistance genes. For example, strA, aac(6′)-Ie–aph(2″)-Ia and blaZ were often found on plasmids, whereas vanX remained chromosomally encoded. Phenotypic assays confirmed high intrinsic resistance to vancomycin in both species, with L. plantarum showing a higher overall frequency and diversity of resistant phenotypes compared to L. paracasei. Conclusions: The co-occurrence of multiple resistance determinants, including plasmid-encoded ones, in most strains suggests that even autochthonous isolates from artisanal products may represent potential reservoirs for transmissible resistance genes. Full article

Bacterial contaminants in ambulances could have a major impact on morbidities, mortalities, and healthcare resources, especially if these bacteria are antimicrobial-resistant. As far as we know, this is the first study in Al-Qassim region to evaluate the prevalence of bacterial contaminants in swab samples obtained from ambulances from Alqwarah General Hospital, Al-Qassim region, Saudi Arabia as an indicator for evaluation of the implemented infection control measures, and screen the antibiotics profiles of the isolates against the most regularly used antimicrobials. In total, 204 samples were collected from the ambulances following patient transport. To evaluate the effect of vehicle decontamination, 204 swabs were collected from the same sites of the ambulances immediately after cleaning and disinfection. The isolates were identified using standard bacteriological and biochemical methods, as recommended by the Clinical Laboratory Standard Institute (CLSI). The antibiotic susceptibility patterns were assessed using the Kirby–Bauer disc diffusion method. The prevalence of bacterial contamination in the samples collected following patient transport was 46.08%. In total, 83.33%, 75.00%, and 66.66% of the samples collected from DC shock apparatuses, ceilings, and emergency personnel seats, respectively, were contaminated. Furthermore, ceilings, DC shock apparatuses, emergency personnel seats, cervical collars, and monitors were found to harbor 10.8%, 9.8%, 7.8%, 6.8%, and 6.8% of the 102 bacterial isolates, respectively. Gram-positive organisms represented 96.1% of all bacterial isolates. Bacillus spp. was the most common isolate, accounting for 60.8% of all bacterial isolates. Although Pseudomonas aeruginosa and Proteus spp. isolates were sensitive to all the tested antimicrobials, many Gram-positive bacterial isolates were resistant to some antibiotics in variable frequencies. After 48 h of aerobic incubation (with or without 5–10% CO₂) on nutrient, blood, chocolate, and MacConkey agar plates at 37 °C, no bacterial growth was detected in the samples collected immediately following cleaning and disinfection. This is the second Saudi study to evaluate the prevalence of bacterial contaminants in Saudi Arabian ambulances, and it could help health policy makers in improving the implemented infection prevention and control measures in Saudi Arabian ambulances. The samples taken after patient transport revealed bacterial contaminants with varying rates of antimicrobial resistance. Policies ensuring the optimal cleaning and disinfection of ambulances can minimize the potential of bacterial infection for high-risk patients, their relatives, and healthcare providers. Full article