Search Results (14,564)

Brown spot on the leaf sheath is an emerging disease of sweet corn (Zea mays L.) in Sinaloa, Mexico, with an unknown etiology. This study aimed to identify the causal agent of the disease and assess its pathogenicity on commercial sweet corn hybrids. Bacterial strains were isolated from symptomatic leaf sheaths collected from commercial fields. Identification was performed through biochemical profiling (API 50CHB/E), pathogenicity tests on alternative hosts (potato, onion, celery), and molecular analysis (16S rRNA and recA genes sequencing and phylogenetic reconstruction). Pathogenicity and virulence were confirmed by inoculating four sweet corn hybrids in a greenhouse. The strains were Gram-negative rods, identified as Burkholderia gladioli based on biochemical profiles and molecular data (99% 16S rRNA+ recA similarity; phylogenetic clustering within the B. gladioli clade). In greenhouse trials, the strains induced brown spot lesions on the leaf sheaths of all tested hybrids, replicating field symptoms fulfilling Koch’s postulates. This is the first report of B. gladioli as the causal agent of brown spot on the leaf sheath of sweet corn in Mexico. The pathogen’s broad host range highlights its potential as an emerging threat to horticultural crops in the region. Full article

Background/Objectives: Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli are priority antimicrobial-resistant pathogens with significant implications for food safety and public health. Food-producing animals and their derived products represent a key interface for zoonotic transmission, yet prevalence data across Nigeria remain fragmented and unsynthesized. This systematic review and meta-analysis assessed the prevalence, species distribution, geographical patterns, and detection methods of ESBL-producing E. coli in food-producing animals and animal-derived food products across Nigeria. Methods: A comprehensive search of PubMed, Web of Science, Scopus, and African journals online was conducted for studies published between January 2000 and January 2026, following PRISMA 2020 guidelines. Twenty eligible studies collectively analyzed 5104 samples, and 984 ESBL-positive isolates were included in the meta-analysis. Results: The overall pooled prevalence of ESBL-producing E. coli was 17.0% (95% CI: 13.0–21.0%; I² = 89.4%). Subgroup analysis by animal species revealed the highest pooled prevalence among caprine (32.0%, 95% CI: 17.0–52.0%), bovine (24.0%, 95% CI: 17.0–33.0%), porcine (17.0%, 95% CI: 7.0–36.0%) and avian species (13.0%, 95% CI: 9.0–19.0%). Animal-derived food products showed a pooled prevalence of 19.0% (95% CI: 17.0–21.0%). Regional analysis showed the highest pooled prevalence in South-West (19.0%, 95% CI: 13.0–27.0%) and South-South (19.0%, 95% CI: 9.0–34.0%). Studies using combined culture and molecular methods reported higher pooled prevalence (19.0%, 95% CI: 14.0–25.0%) than culture alone (12.0%, 95% CI: 8.0–18.0%). However, the difference between subgroups was not statistically significant (test for subgroup differences: p = 0.0563). Conclusions: These findings confirm extensive ESBL-producing E. coli circulation in Nigerian food-producing animals and highlight critical gaps in antimicrobial stewardship, veterinary surveillance, and food safety infrastructure, underscoring the urgent need for coordinated One Health strategies to contain the spread of resistant strains through the food chain. Full article

Peripheral nerve injuries involving critical-sized gaps remain a major clinical challenge. Although autologous nerve grafting is considered the gold standard for peripheral nerve repair, its clinical application is limited by the availability of donor nerve tissue and the risk of donor-site morbidity, including sensory deficits and functional impairment. Therefore, nerve guidance conduits (NGCs) have emerged as a promising alternative when combined with bioactive modulation strategies. In this study, we evaluated bisvinyl sulfonemethyl (BVSM)-crosslinked gelatin conduits integrated with electrical stimulation (ES) at different frequencies (0, 2, 20, and 200 Hz) in a rat sciatic nerve defect model over a 4-week recovery period (n = 10 per group). Structural regeneration was assessed by morphometric analysis, electrophysiology, macrophage infiltration, CGRP immunoreactivity, retrograde Fluorogold tracing, quantitative PCR of growth factors and inflammatory cytokines, and behavioral testing. Among all stimulation paradigms, low-frequency ES at 2 Hz produced the most pronounced regenerative effects. The 2 Hz group demonstrated significantly greater axon number, axonal density, and regenerated nerve area compared with control and high-frequency groups (p < 0.05). Electrophysiological assessments revealed improved nerve conduction velocity, higher MAP amplitudes, and shorter latencies. Enhanced macrophage recruitment and elevated CGRP expression were observed, suggesting coordinated neuroimmune and neurochemical activation. Gene expression analysis indicated upregulation of neurotrophic factors and balanced inflammatory cytokine responses under low-frequency stimulation. In contrast, high-frequency stimulation (200 Hz) failed to enhance overall regeneration and showed reduced axonal metrics, suggesting possible overstimulation-associated suppression. Collectively, these findings demonstrate that BVSM-crosslinked conduits provide a stable and biocompatible regenerative scaffold, and that appropriately tuned low-frequency electrical stimulation (2 Hz) optimally enhances structural, molecular, and functional recovery. The integration of material engineering with bioelectrical modulation represents a promising strategy for next-generation bioelectronic interfaces in peripheral nerve repair. Full article

Background/Objectives: Staphylococcus aureus, particularly methicillin-resistant strains, is a leading cause of severe pneumonia. Understanding local molecular epidemiology, including virulence gene profiles and antimicrobial resistance (AMR) mechanisms, is crucial for effective infection control. This pilot study aimed to characterize S. aureus isolates from pneumonia patients in Karaganda, Kazakhstan. Methods: We collected 48 respiratory samples from patients with pneumonia across three medical institutions. Bacterial identification was performed using MALDI-TOF MS. Antimicrobial susceptibility testing (AST) was carried out using European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Whole-genome sequencing of S. aureus isolates was conducted on an Ion Torrent S5 platform. Genomic analysis included multilocus sequence typing (MLST), identification of virulence and AMR genes, and phylogenetic reconstruction. Results: S. aureus was identified in 14.6% (n = 7) of pneumonia cases included in this study. All isolates (100%, n = 7) were phenotypically resistant to benzylpenicillin. The mecA gene was detected in 57.1% of isolates (n = 4), while phenotypic resistance to methicillin was observed in 28.6% (n = 2) of the isolates. Resistance to azithromycin (57.1%, n = 4) and levofloxacin (42.9%, n = 3) was observed among the isolates. Two isolates (28.6%) were multidrug-resistant (MDR). Genomic analysis revealed the prevalence of the ST22 clone (57.1%, n = 4) in the studied cohort. Other sequence types were ST97, ST8, and ST45 (14.3% each). Phylogenetic analysis showed clustering consistent with MLST profiles. All isolates carried a conserved core virulence arsenal, including hemolysin (hla, hlg), biofilm-forming genes (icaADBC), immune evasion genes (sak, scn), and iron acquisition genes (isd). The Panton–Valentine leukocidin (PVL) genes were detected in three isolates. AMR gene analysis revealed the ubiquitous presence of mepA and tetracycline efflux pump genes, along with regulatory genes (arlRS, mepR, mgrA). The blaZ and ermA genes were not detected despite high phenotypic resistance to penicillin and macrolides. Conclusions: This study reports the identification of the virulent and resistant ST22 S. aureus clone in pneumonia cases in Karaganda, Kazakhstan. The discordance between phenotypic and genotypic AMR profiles underscores the necessity for integrated diagnostic approaches. Full article

This study aimed to investigate the molecular mechanisms underlying dopaminergic injury induced by gestational and lactational atrazine (ATR) exposure in rat offspring, with a particular focus on non-coding RNA-mediated regulation. Pregnant rats were exposed to ATR during gestation and lactation. Offspring underwent behavioral testing at postnatal day 21 (PND21) and were sacrificed for midbrain tissue collection at PND28. Behavioral alterations, histopathological changes in the substantia nigra, and dopaminergic marker expression were assessed to evaluate ATR-induced neurotoxicity. Whole-transcriptome sequencing was then performed to identify differentially expressed mRNAs, miRNAs, and lncRNAs, followed by co-expression, protein–protein interaction, and competing endogenous RNA (ceRNA) network analyses. Key targets were validated by qRT-PCR. Candidate molecules identified from transcriptomic and ceRNA analyses were further examined in an ATR-induced neurotoxicity model established in RA-differentiated SK-N-SH cells. Dual-luciferase reporter, Ago2-RNA immunoprecipitation, and biotin-labeled RNA pull-down assays were used to examine putative binding relationships and molecular interactions. In addition, lentivirus-mediated Elavl4 overexpression was performed to further evaluate the role of this candidate regulator in ATR-induced Nurr1 downregulation. Gestational and lactational ATR exposure induced significant behavioral abnormalities in rat offspring. These changes were accompanied by histopathological alterations in the substantia nigra, including reduced TH immunoreactivity, as well as abnormal expression of dopaminergic markers, characterized by decreased TH and Nurr1 levels and increased α-syn expression. Together, these findings indicate the presence of dopaminergic injury. Whole-transcriptome analysis further revealed widespread dysregulation of mRNAs, miRNAs, and lncRNAs in ATR-exposed offspring. Subsequent integrative analysis suggested a potential ceRNA regulatory relationship among Elavl4, miR-301a-5p, and Nurr1, which was further supported by qRT-PCR. Dual-luciferase reporter, RIP, and RNA pull-down assays supported direct interactions between miR-301a-5p and both Elavl4 and Nurr1, as well as their association with the Ago2-containing silencing complex. Moreover, Elavl4 overexpression partially reversed ATR-induced Nurr1 downregulation in vitro. Gestational and lactational ATR exposure induced behavioral abnormalities and dopaminergic injury in rat offspring. Whole-transcriptome analysis combined with experimental validation suggests a potential association between the Elavl4/miR-301a-5p/Nurr1 ceRNA axis and ATR-induced dopaminergic injury, providing insight into the post-transcriptional mechanisms underlying developmental neurotoxicity. Full article

Infectious bronchitis virus (IBV) is an avian coronavirus associated with respiratory, renal, and reproductive disease in chickens, with important economic consequences in intensive poultry production. This study aimed to estimate the seroprevalence of anti-IBV antibodies in vaccinated broiler flocks reared in south-western Romania and to characterize its distribution across counties and study years. Between 2018 and 2021, a total of 2466 blood samples were collected from Ross 308 broilers aged 35–45 days originating from five commercial farms (one per county) located in Caraș-Severin, Dolj, Gorj, Hunedoara, and Vâlcea. Samples were obtained from 137 production halls/series. Sera were tested using a commercial indirect ELISA kit and classified according to the manufacturer’s criteria based on the sample-to-positive (S/P) ratio and the corresponding antibody titer threshold. Overall, 2115/2466 sera were positive (85.77%) and 351/2466 were negative (14.23%). Anti-IBV antibodies were detected in all halls (137/137, 100%), although negative sera were recorded in 87/137 halls (63%). Seroprevalence by county ranged from 78.67% (Vâlcea) to 89.24% (Hunedoara). Significant differences in the proportions of positive and negative sera were identified between several county pairs by Fisher’s exact test. These findings indicate widespread serological evidence of anti-IBV antibodies in vaccinated broiler flocks from south-western Romania, which may reflect vaccine-induced immunity and/or field exposure. The results support the need for continued serological monitoring, alongside targeted molecular investigations to differentiate vaccine strains from circulating field variants. Full article

Background: Chronic stress is a major contributing factor to mood disorders, including depression and anxiety; however, the molecular mechanisms underlying individual differences in susceptibility to such disorders remain poorly understood. DNA methyltransferase 3a (Dnmt3a), a key epigenetic regulator, has been increasingly implicated in stress-related neurobiological adaptations. In this study, we employed a well-established mouse model of chronic social defeat stress (CSDS) to investigate the functional role of Dnmt3a in modulating individual susceptibility to social stress. Methods: Male C57BL/6J mice were exposed to chronic/submaximal social defeat stress (CSDS/SSDS). AAV vectors were used to achieve Dnmt3a overexpression or global and oligodendrocyte-specific knockdown in the nucleus accumbens (NAc). Behavioral tests, including social interaction, open field, and elevated zero maze, were conducted alongside Western blotting and immunofluorescence assays. Results: CSDS selectively increased Dnmt3a expression in NAc oligodendrocytes of stress-susceptible mice. Overexpression of Dnmt3a in the NAc enhanced susceptibility to stress, whereas its knockdown conferred resilience, without affecting baseline behaviors. Dnmt3a negatively regulated myelin basic protein (MBP) and dopamine D1 receptor expression. Stress-susceptible mice exhibited shortened myelinated segments and reduced D1 receptor levels, while D2 receptor expression remained unchanged. Conclusions: Dnmt3a in NAc oligodendrocytes modulates susceptibility to social stress through a Dnmt3a-MBP/D1 receptor-NAc pathway, highlighting a critical glia-neuron interaction. This mechanism extends our understanding of the neurobiological basis of stress-related disorders and positions Dnmt3a as a promising therapeutic target for developing precision interventions or biomarkers. Full article

Curcumin, a plant-derived polyphenolic compound, exhibits diverse pharmacological activities such as antioxidant, anti-inflammatory, anticancer, neuroprotective, and cardiovascular protective effects, and is widely used in food, medicine, and other fields. However, its poor water solubility and easy oxidative degradation limit its extensive application in biomedicine. To solve these problems, a series of biomedical polyurethanes (Cur-PU) with similar molecular weights but different PEG contents were successfully synthesized using HO-PCL-OH and HO-PEG-OH as soft segments and curcumin as a chain extender. The results indicated that increasing the PEG content reduced the T¹_m, T¹_c, and H¹_c of Cur-PU, along with a slower crystallization rate and lower crystallinity. More importantly, a higher PEG content decreased the water contact angle but increased water solubility and water uptake, which, combined with reduced crystallinity, enhanced hydrophilicity, swelling ratio, curcumin release rate, and degradation rate in an enzymatic solution and pH 8.0 buffer. Thus, precise regulation of Cur-PU’s degradation and curcumin release was achieved by controlling the PEG content. Biocompatibility tests confirmed that Cur-PU exhibited excellent antioxidant and antibacterial activities, making it a highly promising biomedical material. Full article

Background/Objectives: Sosnowsky’s hogweed Heracleum sosnowskyi, which originated in the Greater Caucasus region and spread rapidly across Central and Eastern Europe after being introduced as cattle fodder in the 1950s, is an example of an extremely dangerous invasive species listed by the European Union. This study aimed to estimate the genetic diversity of 6 native populations of Sosnowsky’s hogweed from the Caucasus region of Russia and Georgia, as well as 15 invasive populations from Lithuania and Poland, and to assess the adaptability of hogweed in new environments. Methods: Genetic analyses of plant material were conducted, including DNA extraction, ISSR genotyping, PCR product separation, and subsequent molecular data mining and analysis. Results: A pairwise Mantel test revealed a positive correlation between geographical distance and the genetic diversity of the hogweed populations. The presence of three distinct allele pools was confirmed in the populations under study, with genotypes from Poland dominated by the first allele pool, which had the largest number of polymorphic and private loci. Analysis of molecular variance by origin showed that 99% of the variation was within the analysed hogweed populations, with only 1% being between them. Native populations from Russia were genetically distinct from those in Poland and Lithuania. Some of the Georgian population shows genetic similarities to Russians, while the rest shows similarities to the secondary invasive Lithuanians. Conclusions: Introduced populations of H. sosnowskyi are characterised by considerable genetic variation, likely resulting from multiple introductions and subsequent evolutionary processes, which may facilitate local adaptation and invasiveness, although overall large-scale genetic differentiation remains low. Full article

The seedlings of the young Atlas cedar (Cedrus atlantica Manetti) are very important for the regeneration and restoration of forest populations of this endemic species, which inhabits a very fragmented area in the highest mountains of North Africa (Algeria and Morocco). There is very minimal information on the diseases that are afflicting these young plants. In this work, Alternaria strains CHP2, S4.2, and SP1.1 were isolated from different plants and subjected to identification and pathogenicity testing. The infected plants developed clear symptoms of light brown disease spots on the leaves with a yellowish or chlorotic halo around them, which gradually developed to a yellowing of the plantlets and their complete drying. Some spots merged to form large areas of necrosis which covered an average of 80% of the plantlets. The impact of the infection on plant physiology was determined using measurements of photosynthetic pigments, which showed reductions of 46.28% in chlorophyll and 59.90% in carotenoids in strains SP1.1 and CHP2, respectively. Molecular characterization of the ITS region of the isolates revealed that strains CHP2 and S4.2 showed high sequence similarity to reference sequences of Alternaria spp., including taxa related to A. destruens and A. murispora, although species-level identification remains tentative. These findings highlight the growing relevance of fungal pathogens in forest regeneration under global climate change. By revealing the pathogenic role of Alternaria species, this study contributes to sustainable forest management and conservation strategies in changing environments. Full article

Background: Standardized and ethically compliant animal models remain essential for improving translational research in Alzheimer’s disease. Although Aβ_1–42-induced rodent models are widely used, methodological variability continues to limit reproducibility. Methods: We explored the feasibility of a stereotactic intrahippocampal Aβ_1–42 rat model established by bilaterally injecting pre-aggregated peptide into the hippocampus of adult Sprague Dawley rats. Model feasibility and targeting accuracy were assessed intraoperatively. Cognitive performance was evaluated using the Y-maze for spatial recognition memory and the novel object recognition (NOR) test. Histological examination was performed using hematoxylin–eosin (H&E) and Congo red staining to assess cytoarchitecture and to provide supportive evidence of amyloid-like deposits. Results: The surgical procedure was well-tolerated, and the injected animals showed reduced performance in behavioural testing, including reduced spatial recognition memory in the Y-maze and decreased discrimination indices in the NOR test. The animals also showed histological changes, including Congo red-positive birefringent structures consistent with amyloid-like congophilic material. Conclusions: This study presents a feasible experimental framework for intrahippocampal Aβ_1–42 administration, showing behavioural and histological changes under the present experimental conditions. However, further validation, including sham-operated controls and molecular characterization, will be required before these findings can be interpreted as specific to Aβ-driven pathology. Full article

Chitosan bioactivity has been widely evaluated in seed germination; however, its effects remain inconsistent. Some studies report biostimulant effects, while others manifest inhibitory effects, and some show no effect on germination. A major factor contributing to this poor reproducibility appears to be the variation in the degree of polymerization (X), the molar fraction of acetylation (f_A), and the chitosan concentration. However, it remains unclear whether controlling these parameters alone is sufficient to ensure consistent bioactivity in conventional polymeric chitosan samples. To elucidate this, maize seeds (Zea mays L. var. Jubilee) were soaked in chitosan solutions (pH 5) at concentrations ranging from 0.25 to 1.00% w/w for 4 h, as per the literature, to evaluate their effect on germination compared to a control (water). Nine chitosan samples were tested, differing in X (5558 to 17,161) and f_A (0.07 to 0.33). After germination, several response factors were measured, including fresh and dry biomass, root number, and root and epicotyl length. The results showed that chitosans with higher X values (9134 to 17,161) inhibit germination, decreasing it by up to a value of 3% ± 6 at 1.00% w/w. Chitosans with a lower X (5694 ± 131) exhibited a reduced inhibitory effect (63% ± 6 to 100%) across all evaluated concentrations. None of the treatments showed biostimulation; instead, chitosan consistently delayed the germination rate compared to the control, confirming an inhibitory effect regardless of the final percentage. Nevertheless, while X and concentration establish the general inhibitory trends, considerable residual variability suggests that these factors alone are insufficient to ensure consistent bioactivity. A Gauge Repeatability and Reproducibility (R&R) analysis provides preliminary evidence suggesting that molecular heterogeneity, specifically dispersity (Ð_X), is a key factor driving the observed inconsistencies and significantly affecting the reproducibility of the results within the scope of this study. Full article

Mesophase pitch (MP) is a high-performance precursor for carbon materials. However, its conventional preparation process is limited by stringent conditions and high costs. In this study, heavy coal tar (HCT) was used as a low-cost carbon source, and polyethylene (PE) was introduced as a modifier to induce MP formation under relatively mild conditions, thereby promoting the thermal polycondensation of HCT. Characterization results show that the addition of different types of PE facilitates the condensation of aromatic molecules and significantly enhances the conversion efficiency of HCT to MP. Among the tested PE types, HDPE exhibits the best performance, with an optimal addition of 6 wt.% at 400 °C, yielding the highest number of uniform mesophase carbon microspheres and the most ordered structure. Based on comprehensive characterization data, an average molecular structure model of the product was constructed, addressing a research gap regarding the role of PE in the thermal polycondensation of HCT. This work provides a new pathway for the energy-efficient preparation and property regulation of MP. Full article

Exposure to airborne pollen allergens is a major trigger of respiratory allergy, whose prevalence continues to rise throughout Europe. In southern Portugal, the Mediterranean climate and extensive vegetation diversity promote high pollen loads, particularly from the Amaranthaceae family. This retrospective observational study aimed to characterise the sensitisation profiles of patients with positive skin prick tests (SPTs) to Chenopodium album and/or Salsola kali, the dominant Amaranthaceae species in the region. Data from 346 patients were analysed, including demographic and clinical characteristics, SPT results, and specific IgE sensitisation to molecular allergens. Of these, 35% were positive for C. album only, 13% for S. kali only, and 51% for both. In molecular testing, 54% of S. kali-sensitised patients were positive to Sal k 1, whereas only 4% of C. album-sensitised patients were positive to Che a 1. Sensitisation to panallergens such as profilins and Ole e 1-like proteins was frequent, suggesting extensive IgE cross-reactivity between these taxa. A significant correlation in wheal size (r = 0.53, p < 0.0001) further supports shared allergenic determinants. Despite higher SPT positivity to C. album, S. kali is likely the predominant sensitising source in this population. These findings highlight the importance of molecular-based diagnostics to distinguish genuine sensitisation from cross-reactivity in Mediterranean settings. Full article

Food safety, nutrition, and public health are actual economic and medical problems. Sweetness is an important feature of food technology. Models for the sweetness of special organic compounds used in the food industry are suggested. The models are built using the CORAL software. New statistical coefficients of predictive potential are studied. These are the index of ideality of correlation (IIC) and correlation intensity index (CII). The effectiveness of using the IIC and CII has been tested in simulated sweetness via Monte Carlo optimization of correlation weights for molecular features extracted from Simplified Molecular Input Line Entry System (SMILES) strings. Both factors have been shown to improve the model’s statistical quality on the calibration and validation sets. However, this is accompanied by a decrease in the statistical quality of the training sets. Full article