Search Results (13,653)

Interest is growing in the antimicrobial potential of the non-psychoactive cannabinoids, such as cannabidiolic acid (CBDA) and cannabigerolic acid (CBGA), and their metal systems. The present study follows on from previous potentiometric and ESI-MS studies confirming the formation of stable zinc(II) species with cannabinoid acids in an alcohol–water environment under physiological conditions. The antibacterial action of the compounds was assessed against reference Gram-negative strains (Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis) and Gram-positive strains (Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis) using minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) assays. Their cytotoxicity was also evaluated in vitro using mouse fibroblasts. The tested compounds were found to demonstrate pronounced selectivity against Gram-positive bacterial strains compared to Gram-negative bacteria. The antibacterial efficacy of the free ligands was enhanced by the presence of Zn(II) in the solution: the equilibrium mixtures exhibited greater inhibitory activity against E. faecalis and S. epidermidis, with MIC and MBC values being non-cytotoxic toward L929 fibroblasts under the tested in vitro conditions. However, Gram-negative bacteria were only found to be susceptible at elevated concentrations, which also induced cytotoxic effects. Among the free ligands, CBGA exhibited slightly stronger antibacterial activity than CBDA. Full article

Background/Objective: Antimicrobial resistance poses a critical public health crisis, highlighting the urgent requirement to investigate bacterial evolutionary adaptations and pioneer alternative therapeutics. Consequently, bacteriophages and metal-based compounds are emerging as viable options to combat drug-resistant infections. Building on our finding that T4 phage resistance in E. coli B also confers adaptation to high iron(III), we used RNA-sequencing (RNA-seq) to explore bacterial gene expression in resistant and control populations. We analyzed samples from our five experimental groups—Ancestor (ANC), control (CON), phage-selected (Phage), iron(III)-selected (FE), and phage/iron(III)-selected (PF), to understand how these regimes drive transcriptional changes. Method: Total RNA was extracted using the TRIzol protocol, and sequencing libraries were prepared with the Illumina RNA Total Library Prep Kit. Sequencing was performed on the Illumina NextSeq 1000/2000 platform. Reads were aligned to the E. coli B ATCC 11303 reference genome, and pairwise comparisons between the five experimental groups were conducted to determine differential gene expression profiles. Results: Principal component analysis (PCA) showed that iron-adapted populations (FE and PF) separated distinctly from the Ancestor and control populations along PC1 (capturing 40% of the variance), while the phage-selected replicates were split, with one (Phage5) clustering with CON3 and two (Phage2, Phage4) falling closer to, but clearly separated from, the Ancestor. Differential expression analysis (P_adj < 0.05 and |log₂FC| ≥ 1) revealed extensive transcriptional rewiring, with 482 and 381 differentially expressed genes (DEGs) in the FE and PF populations, respectively, compared to the Ancestor, and 177 DEGs in the phage-selected population compared to the Ancestor. The direct pairwise comparison between the iron-selected and phage/iron-selected populations yielded zero DEGs, demonstrating that both iron-adapted populations converged on a near-identical gene expression profile regardless of their distinct genetic and evolutionary backgrounds. Conclusions: This study suggests that pmrB and arn pathway genes may serve as primary markers for resistance to iron stress. These results are significant because they demonstrate a coordinated, multi-gene defense mechanism in E. coli B against high iron(III) stress, in which the arn operon and eptA remodel lipid A and the outer membrane, while glycerol-3-phosphate metabolism and phage-shock/chaperone pathways are repressed. Full article

Antimicrobial resistance in various microorganisms and opportunistic pathogens associated with HIV/AIDS poses a serious threat to human life and healthcare systems worldwide. Different forms of cancer are likely to arise in immunocompromised patients. The antimicrobial and anticancer effects of methanol extract and fractions from Raphionacme hirsuta have been investigated. The carbon tetrachloride fraction showed a remarkably low minimum inhibitory concentration (MIC) of 0.02 mg/mL against Escherichia coli, Mycoplasma hominis, and Cryptococcus neoformans, while the n-hexane fraction showed a similar MIC against C. neoformans. Furthermore, the carbon tetrachloride fraction exhibited promising IC₅₀ values of 18.21 and 25.22 µg/mL against HeLa and MCF-7 cancerous cell lines, respectively. The fraction was subjected to GC-TOF-MS and yielded four major compounds, including 7,9-Di-tert-butyl-1-oxaspiro (4,5) deca-6,9-diene-2,8-dione (5.322%), Hexanedial (3.691%), 4-(4-tert-Butylphenyl)-1,3-thiazol-2-ylamine (3.329%), and Di-n-decylsulfone (3.201%). These substances could potentially account for the plant species’ initial biological activity, which is why it is necessary to investigate their in vivo actions. The gummy extract had less biological activity than the fractions. To the best of our knowledge, this is the first study to report the antimicrobial and anticancer activities, as well as the phytochemistry, of the plant species. Full article

Runoff from manure-fertilized farmlands is an important pathway for microbial contamination of receiving waters within a One Health framework. Although organic fertilizers improve soil quality, their influence on pathogen release under mixed fertilization remains insufficiently resolved. This study aims to establish a quantitative framework linking fertilization intensity to pathogen export, which is essential for developing risk-informed nutrient management strategies. Therefore, controlled simulated rainfall experiments (60 mm·h⁻¹) were conducted on soil plots receiving three nitrogen-equivalent fertilizer regimes: T1 (100% inorganic fertilizer), T2 (37.5% organic nitrogen replacement), and T3 (50% organic nitrogen replacement). Metagenomic sequencing and qPCR (targeting 16S rRNA, E. coli, Cryptosporidium, etc.) were used to characterize pathogen-marker sources, initial soil pathogen-marker burdens, and runoff dynamics during a 50 min rainfall event. A total of 29 pathogen-marker taxa were detected among the 41 targeted taxa. Higher proportions of organic fertilizer were associated with greater initial pathogen-marker loads in the soil and greater cumulative export in runoff, with T3 consistently exhibiting the highest levels across indicators. Based on the two-pool model developed in this study, the fitted total release potential (Total M) of Escherichia in T3 reached ~2.6 × 10⁹ copies·m⁻², compared with ~1.3 × 10⁹ in T1 and ~6.8 × 10⁸ in T2. Interestingly, the relative ranking between T1 and T2 varied among specific pathogen markers, suggesting a potential environmental buffering capacity at moderate organic substitution levels. Across all treatments, pathogen-marker concentrations peaked during the early stages of rainfall, indicating a pronounced first-flush effect. Furthermore, bacterial indicators were mobilized more readily than fungal and protozoan targets, the latter of which were more strongly retained by the soil matrix. Overall, the results suggest that optimized organic–inorganic fertilization ratios, combined with improved manure stabilization, are essential for mitigating downstream microbial contamination potential within a One Health framework. Full article

Lactobacillus amylovorus has been reported to inhibit Escherichia coli growth in vitro and to modulate intestinal function and microbial composition. However, whether L. amylovorus can protect weaning piglets from E. coli-induced growth retardation and intestinal dysfunction remains unclear. In the present study, we challenged weaning piglets with E. coli K88 and supplemented their diet with L. amylovorus. Our results demonstrated that L. amylovorus supplementation improved growth performance and reduced diarrhea incidence in E. coli-challenged piglets. Furthermore, it enhanced plasma antioxidant capacity and reduced levels of pro-inflammatory cytokines. L. amylovorus alleviated E. coli-induced villus atrophy and disruption of villus architecture, as evidenced by improved histological morphology. Microbiota profiling showed that L. amylovorus improved gut microbial composition, characterized by increased abundance of Muribaculaceae and Lactobacillaceae. Ileal transcriptome analysis indicated that L. amylovorus restored the expression of genes primarily involved in nutrient metabolism. Notably, L. amylovorus-derived extracellular vesicles (EVs), but not EV-free supernatant, inhibited E. coli growth in vitro. Collectively, these findings suggest that L. amylovorus supplementation enhances growth performance, attenuates inflammation, and improves intestinal morphology, function, and microbial homeostasis in E. coli-challenged weaning piglets, potentially mediated by its EVs. Full article

Objectives: Diabetic foot infections are a major cause of morbidity and amputation, and increasing antibiotic resistance complicates their management. This study aimed to evaluate longitudinal changes in antibiotic resistance among bacterial pathogens isolated from patients undergoing toe amputation due to diabetic foot infections. Methods: This retrospective, single-center study included patients who underwent toe amputation for diabetic foot infections between 2013 and 2024. Microbiological culture results and antimicrobial susceptibility data were analyzed across three consecutive time periods: 2013–2016, 2017–2020, and 2021–2024. Results: A total of 351 patients were included (mean age, 64.1 years; 64% male). A history of dialysis was present in 30% of patients, and 54% had a history of prior hospitalization. A total of 351 patients were included in the study. A total of 378 bacterial isolates recovered from positive microbiological cultures were included in the antimicrobial susceptibility analysis. The most frequently isolated microorganisms were Escherichia coli, Enterococcus spp., coagulase-negative Staphylococcus, and Staphylococcus aureus. Among Enterobacterales isolates, statistically significant increases in resistance across the three consecutive time periods were observed for amoxicillin–clavulanate (p = 0.009), piperacillin–tazobactam (p = 0.002), trimethoprim–sulfamethoxazole (p = 0.012), and meropenem (p = 0.027), whereas the increase in imipenem resistance did not reach statistical significance (p = 0.054). Within Staphylococcus spp., a statistically significant increase in resistance across the three consecutive time periods was observed only for ciprofloxacin (p = 0.047). Conclusions: Changes in antimicrobial resistance rates were observed among bacterial isolates recovered from diabetic foot infections across the three consecutive time periods, highlighting the importance of regional surveillance and up-to-date local resistance data for guiding empirical antibiotic therapy. Full article

Dissolved organic matter (DOM) plays a key role in shaping lake microbiomes and water quality, yet its spatial variability and regional links to microbial activity remain unclear. Using three-dimensional excitation–emission matrix and self-organizing map analysis on 38 samples from a human-impacted lake network in Hubei (affected by tourism, agriculture, and urban areas), this study clarifies DOM heterogeneity and its environmental connections. Microbial metabolic activity represented by total bacterial content (BC) and Escherichia coli (E. coli) activity was rapidly and automatically measured with a ColiMinder device. Random forest (RF) modeling and principal component analysis (PCA) were applied to identify key drivers of microbial activity and to clarify correlations between DOM characteristics and microbial activitiy. Results indicated that although DOM in all three sectors primarily originated from microbial activities during the flat-water period, Tuanhu (TH) exhibited a higher degree of DOM humification and a larger average relative molecular mass, reflecting stronger terrestrial source characteristics. RF analysis identified NH₄⁺ as the main predictor of both BC and E. coli levels, while total organic carbon (TOC) and total nitrogen (TN) were also important predictors. PCA further revealed clear differences in DOM composition across the lakes. DOM in TH was predominantly autochthonous, whereas DOM in Miaohu (MH) and Guozheng (GZ) was mainly of humic origin. This study adopts an integrated method combining rapid microbial detection, EEM and DOM–microbe correlation analysis to analyze human disturbances across segmented connected lakes in Hubei. It provides scientific support for targeted water quality management of human-influenced freshwater. Full article

Shiga toxins (Stx), produced by Stx-producing Escherichia coli (STEC), are known to target Gb3-expressing cells, contributing to organ pathology such as in the kidney and brain. However, the sensitivity of human B-lymphoblastoid cell lines to Stx2 and their Gb3 expression profiles remain poorly understood. In this preliminary study, we assessed the susceptibility of human B-lymphoblastoid cell lines to Stx2 and identified distinct resistance and sensitivity patterns. Eight representative lines were further analyzed for Gb3 expression by mass spectrometry and flow cytometry. Susceptible cell lines (e.g., GM02473 and GM07019) displayed significantly higher total and membrane-associated Gb3 levels, while resistant lines had lower or undetectable Gb3. Exosomal Gb3 quantification revealed similar expression trends, contradicting the hypothesis that Gb3-positive exosomes neutralize Stx2. Interestingly, resistant cell line GM17658 showed discordant total and exosomal Gb3 levels. Immunofluorescence microscopy and flow cytometry revealed heterogeneous Gb3 expression within cell lines, with susceptible lines having a higher proportion of Gb3-positive cells. These findings suggest that Stx2 susceptibility is associated with Gb3 expression frequency rather than intensity and raise the possibility that Gb3-positive exosomes might contribute to toxicity. Future studies need to validate the role of exosomal Stx2 transfer and the functional impact of variable levels of Gb3-positive versus Gb3-negative subpopulations in toxin response. Full article

Background and objectives: Extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Enterobacteriaceae represent an increasing One Health concern because food-producing animals may act as reservoirs of antimicrobial-resistant bacteria with potential transmission to humans. Therefore, this study aimed to assess the prevalence and genomic characteristics of ESBL- and carbapenemase-producing Enterobacteriaceae in livestock and farmers, and to evaluate genomic overlap between animal and human ESBL-producing Escherichia coli to explore potential shared origins and interspecies transmission. Methods: We conducted a cross-sectional study in Osona (Catalonia, Spain), sampling livestock (swine, cattle, poultry, and horses) and farmers. ESBL-, AmpC-, and carbapenemase-producing Enterobacteriaceae were identified and characterized using whole genome sequencing (WGS). Genomic analyses included sequence typing (ST), serotyping, virulence-associated genes, antimicrobial resistance determinants, and plasmid replicon profiling. Results: A total of 945 animals were analysed. ESBL-producing Enterobacteriaceae were predominantly detected in swine, with 63.5% (127/200) of animals testing positive, including four ESBL + AmpC-producing isolates and two carbapenem-resistant Enterobacteriaceae. No ESBL-, AmpC- or carbapenemase-producing isolates were identified in cattle (0/360) or poultry (0/171), and a low prevalence was observed in horses (7.0%, 15/214). A total of 64 farm workers were analysed. ESBL-producing E. coli were detected in 46.7% (7/15) of swine farmers and 8.3% (2/24) of cattle farmers, while no ESBL-producing isolates were found among poultry farmers (0/8) or equine caretakers (0/17). A total of 162 isolates were analyzed by WGS, showing high genetic diversity. Among the 127 Escherichia coli isolates, the most prevalent were ST10 (18/127, 14.2%), followed by ST453 (7/127, 5.5%), ST515 (7/127, 5.5%), and ST10562 (7/127, 5.5%). Virulence-associated gene profiles were heterogeneous, although genes related to stress tolerance and intestinal colonization predominated among ESBL-producing E. coli isolates from swine, including terC (54/127, 42.5%), csgA (41/127, 32.3%), nlpI (41/127, 32.3%), and fimH (39/127, 30.7%). ESBL production among E. coli isolates from swine was primarily mediated by blaCTX-M genes (89/127, 70.1%), with additional contributions from blaSHV (34/127, 26.8%) and blaTEM (40/127, 31.5%). Among swine isolates, IncX1 (100/127, 78.7%), IncFIB(AP001918) (82/127, 64.6%), IncI1-I(Alpha) (69/127, 54.3%), and IncFII (54/127, 42.5%) were the most frequently detected plasmid replicons. Two carbapenem-resistant isolates carrying blaOXA-48 were identified in swine, including E. coli ST58 and K. oxytoca ST145, both associated with IncL plasmids. Conclusions: Swine appear to constitute the primary reservoir of ESBL-producing E. coli. The genomic relatedness observed between animal and human isolates supports shared exposure to a common ecological pool of multidrug-resistant bacteria. The identification of blaOXA-48-producing Enterobacterales associated with IncL plasmids further highlights the public health relevance of livestock-associated antimicrobial resistance. However, the cross-sectional design precludes inference of transmission pathways or transmission directionality. Longitudinal studies are needed to elucidate the dynamics of interspecies transmission. Full article

In recent decades, kombucha, a beverage produced through the fermentation of tea leaves by a symbiotic culture of bacteria and yeasts (SCOBY), has gained considerable popularity and attracted increasing scientific interest. However, the influence of SCOBY composition on kombucha characteristics remains insufficiently explored. In the present study, green tea kombuchas fermented with four different SCOBYs (SCs) were monitored over 21 days through physicochemical (pH), biochemical (total soluble solids (TSS), ethanol, proteins, and phenolic compounds), and microbiological (yeasts, acetic acid bacteria, and lactic acid bacteria) analyses. Based on these parameters, the most suitable bottling time was established for each kombucha (7 days for SC3 and SC4; 10 days for SC1 and SC2), considering acceptable and safe pH values, reduced TSS levels (4.3–4.6 °Brix), ethanol concentrations below 1.2%, and increased protein and phenolic compound contents, all of them differently affected by the SC used. At the selected bottling stages, the kombuchas exhibited DPPH^● and ABTS^●+ radical scavenging capacities (TEAC values up to 7.7 and 36.7 µmol/mL, respectively) and inhibitory activity against an Escherichia coli strain. These preliminary findings suggest the impact of SC composition and support further studies involving advanced phenolic, microbiological, and functional characterization approaches. Full article

This paper presents the synthesis and characterization of Schiff base ligands (L) derived from NH-pyrazole-indole and their ruthenium(II) complexes of the general formula [Ru(p-cymene)(L)Cl₂]. The structural characterization of the ligands and ruthenium complexes was performed using a range of analytical methods, including infrared spectroscopy (IR), Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, elemental analysis, mass spectrometry(ESI-MS), density functional theory (DFT) calculations, and single-crystal X-ray diffraction crystallography for two of the four synthesized compounds. Schiff base ligands (L) derived from NH-pyrazole-indole and their ruthenium(II) complexes were evaluated against antibiotic-resistant bacteria. The effect of substituting the ligand with methoxy groups on biological activity was assessed. The antibacterial activity, Minimal Inhibitory Concentration (MIC), and Minimal Bactericidal Concentration (MBC) of the free ligands and the ruthenium compounds were measured against six bacterial isolates (Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, Shigella dysenteriae) and two control strains (Enterococcus faecalis ATCC 29212 and Enterobacter cloacae ATCC 13047) from the ESKAPE group of highly antibiotic-resistant pathogens. The free ligands were inactive, whereas all four ruthenium complexes displayed notable antibacterial activity. In particular, compounds Ru3 and Ru4 exhibited higher activity against Staphylococcus aureus than the Trimethoprim control, with MIC values of 15.60 µg/mL, compared with an MIC > 64 µg/mL for Trimethoprim. The activity of those two complexes was similar to that of Gentamicin against this strain. Molecular docking calculations suggested a possible mechanism of action through binding of the complexes to the active site of S. aureus PBP2a. Full article

Commercial-scale dairy farms produce large volumes of manure, posing environmental, animal health, and public health risks due to persistent pathogens and the accumulation of organic pollutants. This field-scale study evaluated the effects of covered anaerobic lagoons (CLs) and open facultative lagoons (OLs) on microbial reduction, solids stabilization, and manure biogeochemical characteristics on commercial dairy farms in California’s Central Valley during the summer months. Manure samples collected from lagoon inlets, outlets, and secondary lagoons were analyzed for Escherichia coli, total solids (TS), volatile solids (VS), and genomic DNA degradation. CL systems achieved substantially greater E. coli reductions (98.38%; 1.82 log) than OL systems (54.88%; 0.35 log), indicating enhanced pathogen suppression under anaerobic conditions. Progressive declines in genomic DNA concentrations and electropherogram signal intensities across treatment stages further demonstrated microbial biomass degradation during storage. In the CL system, TS concentrations decreased from approximately 0.985% at the inlet to 0.485% at the outlet, representing a 50.7% reduction, with an additional 56% reduction observed in the secondary lagoon. For moisture content, both CL and OL systems exhibited increases of approximately 0.37–0.5% from their respective inlets to outlets, with only marginal increases observed in the secondary lagoon. Comparable trends were observed in the OL system. Significant differences in TS, VS, moisture content, pH, electrical conductivity, and major cations (Na⁺, K⁺, Ca²⁺) occurred between CL and OL systems and among treatment stages. The secondary lagoon further enhanced microbial and solids reductions in both systems. Overall, the findings show that CL systems provide superior pathogen reduction and support biogas recovery, whereas OL systems demonstrate stronger VS stabilization. These results offer practical, field-based insights to inform improved manure management and pathogen mitigation strategies for commercial dairy operations. Full article

Infectious wounds are plagued by persistent infection, uncontrolled inflammation, and delayed repair, while traditional therapies suffer from the poor solubility of natural drugs, low bioavailability, and bacterial drug resistance. To address these issues, this study developed a photo-responsive chitosan composite hydrogel (BBR-AS@Ce6@Matrix) cross-linked by chitosan (CS) and oxidized sodium alginate (OSA), co-loaded with Berberine–Asiaticoside cocrystal (BBR-AS) and chlorin e6-loaded chitosan nanoparticles (Ce6@CS NPs). The BBR-AS co-crystal was prepared by solvent method and verified to significantly improve the solubility and dissolution of asiaticoside. The Ce6@CS NPs were fabricated via non-solvent-assisted counterion complexation, showing high encapsulation efficiency, uniform particle size, and efficient singlet oxygen generation under irradiation. The hydrogel exhibited a three-dimensional porous network, favorable rheology, high water content, pH-dependent swelling and erosion behaviors, and significantly promoted BBR/AS release in vitro. In vitro experiments demonstrated strong antibacterial activity against Escherichia coli and Staphylococcus aureus, good cytocompatibility, and enhanced migration of L929 and Hacat cells. In a rat infectious wound model, the hydrogel combined with light irradiation markedly accelerated wound closure, promoted collagen deposition and angiogenesis, upregulated VEGF/CD31, and downregulated TNF-α/IL-6. In conclusion, BBR-AS@Ce6@Matrix integrates co-crystal solubilization, nanoparticle-facilitated release, and photodynamic synergy to achieve antibacterial, anti-inflammatory, pro-angiogenic and tissue remodeling effects, providing a promising multifunctional platform for infectious wound repair. Full article

In this study, composite nanofibrous membranes composed of poly(vinyl alcohol) (PVA), gelatin, and zein loaded with different contents of dihydromyricetin (DMY) were fabricated via electroblowing spinning (EBS). The effects of DMY content on the microstructure, physicochemical properties, mechanical strength, and functional performance of the membranes were evaluated. Scanning electron microscopy (SEM) analysis showed that the average fiber diameter increased from 174 ± 29 nm to 221 ± 35 nm with increasing DMY content, followed by a slight decrease at higher loading levels, indicating that DMY incorporation influences fiber morphology. Fourier transform infrared spectroscopy (FTIR) results suggested the presence of hydrogen bonding interactions between DMY and the polymer matrix. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) results indicated changes in the physical state of DMY within the nanofibrous system as the loading content increased. All samples exhibited a typical two-stage release behavior, and the highest cumulative release (nearly 55%) was observed at a DMY loading of 22.5%, while further increasing the loading reduced the release efficiency to approximately 45%. The release profiles were well described by a first-order kinetic model. The composite membranes exhibited improved surface hydrophilicity, appropriate water vapor permeability, antioxidant activity, and antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This study demonstrates the successful fabrication of DMY-loaded PVA/gelatin/zein nanofibrous membranes and provides preliminary insights into their structure–property–function relationships, release behavior, antioxidant activity, and antibacterial activity against representative bacteria, although further application-oriented validation is still required. Full article

Selenite bioreduction by food-grade lactic acid bacteria enables mild production of selenium nanoparticles (SeNPs) together with selenium-enriched biomass. Here, a highly Se(IV)-tolerant isolate from Enshi soil was identified as Pediococcus acidilactici JD-21, which efficiently reduced 5 mmol/L Se(IV) and accumulated SeNPs with an average diameter of 46.4 ± 7.7 nm, potentially associated with protein- and polysaccharide-related biomolecules. Selenium enrichment markedly enhanced the antibacterial activity of JD-21 against Escherichia coli, Staphylococcus aureus and Salmonella enteritidis and improved survival in simulated gastric juice, indicating probiotic potential. In a mouse Streptococcus suis infection model, oral-gavage SeNPs alleviated infection-associated weight loss, restored antioxidant enzyme activities and reduced liver and spleen lesions. RNA-seq revealed 537 Se(IV)-responsive genes, with up-regulated redox, lipid/exopolysaccharide and transport pathways and down-regulated growth-related functions. These findings demonstrate that JD-21 is a promising food-grade chassis for producing biogenic SeNPs and selenium-enriched probiotics for selenium fortification and foodborne pathogen control. Full article