Search Results (1,462)

The growing demand for biodegradable and functional packaging has driven research toward polysaccharide-based materials with improved performance. In this study, sodium alginate films were modified using natural deep eutectic solvents (NADES) and acorn polyphenolic extract to enhance their antimicrobial, mechanical, and thermal properties. The films were acquired by solvent casting and characterized through mechanical, spectroscopic, thermal, and microbiological analyses. Both NADES and the polyphenolic extract enhanced tensile strength and flexibility through additional hydrogen bonding within the alginate network, while the extract also introduced antioxidant functionality. Among all tested formulations, the A4E2 film exhibited the most balanced performance. FTIR spectra revealed hydrogen bonding between the film components, and thermogravimetric analysis showed an approximately 15 °C (F-EXT) and 20 °C (F-DES) shift in the main DTG degradation peak, indicating enhanced thermal stability. Controlled-release experiments demonstrated the gradual diffusion of phenolic compounds in aqueous, acidic, and fatty simulants, with an initial release phase within the first 6 h followed by sustained release up to 48 h, confirming the films’ suitability for various food environments. The combined modification reduced the growth of Escherichia coli and Staphylococcus aureus by 30–35%, with inhibition zone diameters reaching 27.52 ± 2.87 mm and 25.68 ± 1.52 mm, respectively, evidencing synergistic antimicrobial activity. These results highlight the potential of NADES- and extract-modified alginate films as sustainable materials for active food packaging applications. Full article

Background: Domestic refrigeration and egg handling are key factors in ensuring household food safety. Inadequate temperature control and poor hygiene in refrigerators can promote the survival and growth of foodborne pathogens. This study aimed to (i) characterize refrigerator temperature profiles and surface microbial contamination and (ii) screen eggs and egg-storage areas for the presence of Salmonella spp. and Campylobacter spp. Methods: Fifty domestic refrigerators were monitored twice in 2024 and 2025 in Porto, Portugal. The temperatures were continuously logged on the lowest shelf, which was swabbed for microbiological analysis. Surface hygiene was evaluated using total viable counts (TVC), Enterobacteriaceae, and Escherichia coli enumerated following ISO methods. Detection of pathogens Listeria monocytogenes, Salmonella spp., and Campylobacter spp. was performed using real-time PCR. Eggs (n = 92 in 2024; n = 88 in 2025), and domestic egg storage areas (total n = 76) were screened for Salmonella and Campylobacter. Results: The mean refrigerator temperatures were 6.0 ± 0.5 °C in 2024 and 6.1 ± 0.5 °C in 2025; 44% and 50% of the units, respectively, exceeded the recommended 6 °C threshold. In 2025, 31 (62%) and 33 (66%) refrigerators showed higher TVC and Enterobacteriaceae counts compared to 2024, whereas E. coli was only detected sporadically. L. monocytogenes, Salmonella spp., or Campylobacter spp. were not recovered from the refrigerator surfaces. Likewise, Salmonella and Campylobacter were not detected in any of the eggs or egg-storage sites. Indicator microorganism’s counts were not associated with the mean temperature. Conclusions: The absence of correlation between ΔT and Δ microbial counts suggests that behaviour-driven hygiene factors, rather than the relatively small year-to-year temperature differences observed, are more influential in determining household bioburden. Maintaining refrigerator temperatures ≤ 6 °C together with simple hygiene practices remains essential for reducing household food safety risks. Full article

Climate variability plays a crucial role in shaping drinking water quality, yet the quantitative links between meteorological factors and microbiological contamination remain underexplored in temperate continental climates. A secondary data analysis was conducted on 15,394 microbiological water quality test results collected between 2015 and 2024, including heterotrophic plate counts (22 °C and 37 °C), coliform bacteria, and Escherichia coli, and their associations with local meteorological conditions across groundwater wells and piped distribution networks were examined. A clear distinction emerged: groundwater wells showed higher vulnerability to primary microbial contamination (coliforms and E. coli), whereas distribution networks exhibited higher odds of heterotrophic plate count exceedances, indicating greater susceptibility to post-treatment microbial regrowth. In groundwater wells, temperature showed strong positive associations with all microbial indicators (p < 0.001), with pronounced summer peaks in coliforms and E. coli, while precipitation triggered short-term contamination spikes characterized by a 2-day lag. In contrast, piped networks exhibited weaker and more delayed meteorological responses. These results highlight the need for a shift from climate-responsive to climate-pre-emptive water quality monitoring by incorporating meteorological forecasts, especially for non-chlorinated groundwater sources. Full article

In precision agriculture, the delineation of Management Zones (MZs) is essential for optimizing input use efficiency and site-specific nutrient management. MZs are established based on spatial variability derived from remote sensing data—such as Normalized Difference Vegetation Index (NDVI) from satellite or UAV-based imagery—and yield maps collected during harvest. However, the microbial community composition of the soil is often overlooked in MZ delineation. To address this gap, we investigated the soil bacterial community structure across different MZs in an arable field. The zones were delineated using NDVI data, soil profiles were described, and bulk soil samples were collected. Soil physicochemical parameters were analyzed in parallel with 16S rRNA gene amplicon sequencing to characterize bacterial community composition and diversity. The results demonstrated that soil texture and soil organic matter content were the primary drivers influencing bacterial community structure across the field. Moreover, patterns in microbial composition aligned closely with MZ delineations, indicating that microbial profiles could aid in better understanding and supporting the nutrient management practices. Our findings suggest that soil microbiological data can enhance the stability and biological relevance of MZ definitions, thereby improving resource allocation, soil health management, and overall sustainability in precision farming systems. Full article

Background: Cognitive aging is a physiological process that involves gradual and mild changes in mental functions. When these changes significantly affect cognitive performance, it is considered cognitive decline. Objective: This analytical cross-sectional pilot study examined the association between periodontal status, systemic conditions, and cognitive performance in middle-aged and older adults. Methods: Forty adults aged 35–59 years (n = 20) and ≥60 years (n = 20) from northeastern Mexico were evaluated. Oral assessments included the Modified Gingival Index and detection of Porphyromonas gingivalis and Fusobacterium nucleatum using qPCR. Cognitive function was evaluated with the Mini-Mental State Examination (MMSE), and frailty with the Clinical Frailty Scale (CFS) and Oral Frailty Checklist (OF-5). Systemic medical history and oral hygiene habits were determined using a questionnaire. Results: MMSE scores were lower in older adults compared with middle-aged adults, and the magnitude of the difference was small. The presence of P. gingivalis or F. nucleatum was similar between groups. Frailty indicators were more prevalent in older adults. Logistic regression identified age and frailty-related variables as the strongest predictors of lower cognitive performance, whereas microbiological findings were not significant predictors. Conclusions: Age and frailty indicators, rather than bacterial presence alone, were associated with reduced cognitive performance in this pilot sample. Although no microbiological differences were observed, the findings highlight the need for larger analytical studies incorporating quantitative bacterial load and additional confounders to better understand the oral–systemic–cognitive interactions. Full article

This article presents the results of the first stage of a four-phase research program aimed at the comprehensive evaluation and enhancement in the functional properties of polymeric packaging films intended for active food packaging systems through their modification with detonative nanodiamonds (DND). Stage I involved the characterization of ten commercial single- and multi-layer films without the addition of DND, differing in structure, base material, thickness, and intended application. The scope of analyses included the assessment of biological and physicochemical properties relevant to food contact, such as surface wettability (contact angle), thermal stability (TGA, DSC), antimicrobial and antiviral activity (using E. coli and M. luteus models), as well as the quality of thermal seals examined by SEM. Biological activity was assessed in accordance with ISO 22196:2011. The results revealed significant differences among the tested samples in terms of microbiological resistance, surface properties, and thermal stability. Films with printed layers exhibited the highest antimicrobial activity, whereas some polypropylene samples showed no activity at all or even supported microbial survival. Cross-sectional analysis of welds indicated that the quality of thermal seals is strongly dependent on the surface properties of the base material. The obtained results provide a reference point for subsequent research stages, in which DND-modified films will be analyzed regarding their effects on mechanical, barrier, and biological properties. Preliminary trials with nanodiamonds confirmed their high application potential and the possibility of producing films with increased hydrophilicity or hydrophobicity and durability, which are crucial for the development of modern active food packaging systems. Full article

This study investigates a mechanically aerated, yeast-free bread technology incorporating apple-derived plant ingredients (juice, purée, and powder) in response to the growing demand for clean-label bakery products. The global bakery sector represents one of the largest food markets worldwide, with the baking yeast segment alone accounting for several billion USD annually, while interest in yeast-free and yeastless-dough products continues to expand. To address technological limitations associated with yeast exclusion, dough aeration was achieved using a two-stage whipping protocol (1000 rpm for 4 min, followed by 500 rpm for 1 min and stabilization at 500 rpm for 1 min under 4.0 ± 0.1 MPa gauge pressure), forming a stable protein–carbohydrate foam system. Rheological evaluation using Mixolab 2 showed that formulations containing 3–5% apple purée exhibited the most favorable dough development characteristics, with stability increasing from 3.30 ± 0.15 min in the control to 8.90 ± 0.20 min. Texture profiling using a CT-2 analyzer equipped with a cylindrical probe (50% compression, 60 mm/min, slices 25 mm thick, n = 5) revealed a significant reduction in crumb firmness, from 3.01 ± 0.15 N in the control to 2.12 ± 0.10 N in the purée- and powder-enriched samples (p < 0.05). Nutritional assessment indicated improvements in vitamin C content (up to 2.23 mg/100 g) and protein quality: the amino acid score, calculated according to FAO/WHO reference patterns on a mg/g-protein basis, increased from 76.5 ± 1.8% to 89.2 ± 2.3%. Microbiological analysis showed reduced total aerobic mesophilic counts after 72 h of storage—4.7 × 10³ CFU/g in the control versus 1.8–3.4 × 10³ CFU/g in apple-enriched breads. Overall, the results demonstrate that mechanical aeration combined with apple-derived ingredients enhances the structural, nutritional, and microbiological quality of yeast-free bread, offering a promising clean-label approach for functional bakery products. Full article

Background and Objectives: Healthcare-associated infections (HAIs) significantly increase morbidity and mortality in critically ill patients, and their burden became more pronounced during the COVID-19 pandemic. However, data describing the temporal evolution of HAIs, pathogen distribution, and associated risk factors across consecutive pandemic waves remain limited. This study aimed to characterize the epidemiology, microbiology, and outcomes of HAIs in COVID-19 intensive care units (ICU) patients and to identify clinical and laboratory predictors of mortality. Materials and Methods: This retrospective observational study included adult patients with RT-PCR–confirmed COVID-19 who developed at least one HAI ≥ 48 h after ICU admission between March 2020 and December 2020, encompassing the first three pandemic waves in Türkiye, in a tertiary-care ICU. Demographic, clinical, laboratory, and microbiological data were collected. Inflammatory markers and severity scores (SAPS-II, MCCI, and NLR) were analyzed. Receiver operating characteristic (ROC) curve analysis was used to determine optimal cut-off values for mortality prediction. Results: Among the 1656 ICU admissions, 145 patients (8.7%) developed HAIs; after exclusions, 136 patients were included in the final analysis. Bloodstream infections were the most frequent HAI (57%), followed by urinary tract infections (31%), ventilator-associated pneumonia (9%), and surgical site infections (1%). Klebsiella pneumoniae was the predominant pathogen, followed by Candida albicans and Acinetobacter baumannii. Multidrug-resistant organisms, including MRSA and VRE, showed variable distribution across pandemic periods. Overall in-hospital mortality was 74.3%. Non-survivors had significantly higher SAPS-II, MCCI, and NLR values. ROC analysis identified NLR > 38.8 and SAPS-II > 35.5 as mortality-predictive thresholds. Dynamic inflammatory marker patterns correlated with infection timing, and early peaks of CRP, WBC, and IL-6 were associated with worse outcomes. Conclusions: HAIs imposed a substantial clinical burden on critically ill COVID-19 patients, with high mortality driven predominantly by multidrug-resistant bloodstream infections. Severity indices and inflammation-based biomarkers demonstrated strong prognostic value. Temporal shifts in pathogen ecology across pandemic waves underscore the need for adaptive infection-prevention strategies, continuous microbiological surveillance, and strengthened antimicrobial stewardship in critical care settings. Full article

Cyanobacterial blooms are an escalating ecological concern driven by eutrophication and climate warming. Bloom-forming cyanobacteria can produce a broad spectrum of bioactive secondary metabolites. Among these, microcystins (MCs) are the most recognised hepatotoxins; however, natural populations of Planktothrix agardhii also synthesise numerous non-ribosomal peptides (NRPs) with poorly understood ecological roles and combined toxic effects. This review demonstrated the role of mixtures of P. agardhii cyanometabolites (oligopeptides and biogenic compounds) in cyanobacterial proliferation, emphasising the rapid evolution of chemotypes. The role of P. agardhii oligopeptides other than MCs in the cyanobacterial toxicity to duckweeds is also discussed. Laboratory experiments indicated that crude extracts containing complex peptide mixtures may inhibit Spirodela polyrhiza growth more strongly than pure MC-LR, suggesting synergistic effects within natural metabolite assemblages. Particular attention is given to variant-specific degradation pathways of MCs within duckweed-associated microbiota. By integrating biochemical, ecological, and microbiological perspectives, this synthesis outlines emerging directions in the study of mixtures of cyanobacterial peptides and other compounds, microbial degraders, and macrophyte-associated bioremediation strategies aimed at mitigating cyanotoxin risks in aquatic environments. Full article

Droplet microfluidics enables high-throughput, compartmentalized reactions using minimal reagent volumes, but most implementations rely on precision-fabricated chips and external pumping systems that limit portability and accessibility. Here, we present a handheld vibrational droplet generator that repurposes a consumer electric toothbrush and a modified disposable pipette tip to produce nearly monodisperse water-in-oil droplets without microfluidic channels or syringe pumps. The device is powered by the toothbrush’s built-in motor and controlled by a simple 3D-printed adapter and adjustable counterweight that tune the vibration amplitude transmitted to the pipette tip. By varying the aperture of the pipette tip, droplets with diameters from ~100–300 µm were generated at rates of ~100 droplets s⁻¹. Image analysis revealed narrow size distributions with coefficients of variation below 5% in typical operating conditions. We further demonstrate proof-of-concept applications in digital loop-mediated isothermal amplification (LAMP) and microbiological colony-forming unit (CFU) assays. A commercial feline parvovirus (FPV) kit manufactured by Beyotime Biotechnology Co., Ltd. (Shanghai, China), three template concentrations yielded emulsified reaction droplets that remained stable at 65 °C for 45 min and produced distinct fractions of fluorescent-positive droplets, allowing estimation of template concentration via a Poisson model. In a second set of experiments, the device was used as a droplet-based spreader to dispense diluted Escherichia coli suspensions onto LB agar plates, achieving uniform colony distributions across the plate at different dilution factors. The proposed handheld vibrational generator is inexpensive, easy to assemble from off-the-shelf components, and minimizes dead volume and cross-contamination because only the pipette tip contacts the sample. Although the current prototype still exhibits device-to-device variability and moving droplets in open containers complicate real-time imaging, these results indicate that toothbrush-based vibrational actuation can provide a practical and scalable route toward “lab-in-hand” droplet assays in resource-limited or educational settings. Full article

The aim of this work was to identify the microbial agent(s) responsible for a structural defect in Provolone Valpadana, Protected Designation of Origin (PDO) cheese, and to establish their spread along the production line. Repeated sampling of defective cheeses and analyses of processing intermediates following two inspections at the cheese factory identified yeasts as the main causative agents. Microbiological analysis highlighted an almost constant presence of yeasts, which dominate over the other microbial groups. Forty yeast isolates from defective cheeses were identified by sequencing the D1/D2 region of the 26S rRNA gene. Saccharomyces cerevisiae, Kluyveromyces marxianus, and Debaryomyces hansenii dominated in all sampled cheeses, followed by D. tyrocola, Pichia kudriavzevii, and Torulaspora delbrueckii. Yeast and bacterial metabarcoding on three cheeses with a yeast count > log 4.0 CFU/mL indicated D. hansenii as the dominant yeast taxon and confirmed the absence of gas-producing bacterial taxa. RAPD-PCR analysis suggested the presence of yeast biofilms in the dairy environment or along the production line, as confirmed by the repeated isolation of specific genotypes of S. cerevisiae, K. marxianus, and D. hansenii in different defective cheeses sampled between April and August 2023, as well as in samples taken following two inspections at the production site, during cheese processing and ripening. Full article

Chronic wounds remain locked in persistent inflammation with high microbial burden, demanding dressings that suppress infection without sacrificing biocompatibility. Bacterial nanocellulose (BNC) is an attractive matrix due to its biocompatibility, nanofibrillar architecture, and moisture retention, but it lacks antimicrobial activity. Here, we engineer BNC membranes post-functionalized with functionalized graphite (f-Gr; predominantly graphitic with residual surface groups) and/or niobium pentoxide (Nb₂O₅), and evaluate four groups: BNC (matrix control), BNC/Nb₂O₅, BNC/f-Gr, and BNC/f-Gr/Nb₂O₅. Physicochemical analyses (Raman and Voigt fitting, FTIR-ATR, XRD, and SEM) confirm a graphitic carbon phase and physical incorporation of the modifiers into the BNC network, with a noticeable shift in the hydration/polarity profile—more evident in the presence of f-Gr. In standardized microbiological assays, BNC/f-Gr promoted a moderate, contact-dependent reduction in bacterial proliferation, particularly against Staphylococcus aureus, whereas BNC/Nb₂O₅ behaved similarly to pristine BNC under the tested conditions. The combined f-Gr/Nb₂O₅ formulation showed an intermediate antimicrobial response, with no clear synergy beyond f-Gr alone. Cytotoxicity assays indicated cytocompatibility for BNC, BNC/f-Gr, and BNC/Nb₂O₅; the combined group displayed a slight reduction that remained within acceptable limits. Overall, BNC/f-Gr emerges as the most promising antimicrobial dressing, while Nb₂O₅ did not significantly enhance antimicrobial performance under the tested conditions and warrants further optimization regarding loading and distribution. Full article

This study evaluated the effect of incorporating chia seed gel powder (CSGP) as a natural, clean-label stabilizer on the physicochemical, functional, microbiological, microstructural, antioxidant, and sensory properties of probiotic low-fat yogurt (PLFY) during 21 days of refrigerated storage. Six formulations were prepared using 0–2.5% CSGP, including Control (0% CSGP), YOG1 (0.5% CSGP), YOG2 (1.0% CSGP), YOG3 (1.5% CSGP), YOG4 (2.0% CSGP), and YOG5 (2.5% CSGP). Results showed that increasing CSGP levels noticeably enhanced the total solids, protein content, viscosity, hardness, and water-holding capacity of the PLFY (p < 0.05), while consistently reducing syneresis. Antioxidant activity also rose with higher CSGP concentrations, with YOG5 exhibiting the greatest DPPH scavenging activity (35.12%). Confocal laser scanning microscopy revealed a denser and more uniform protein network in PLFY fortified with CSGP, consistent with rheological measurements showing increased storage (G′) and loss (G″) moduli. Probiotic viability significantly increased (p < 0.05) in CSGP-added samples, indicating a potential prebiotic effect of CSGP. Sensory results demonstrated that although higher CSGP levels slightly darkened the yogurt color, body, texture, flavor, and total sensory scores improved markedly, with YOG5 gaining the highest total score (81.77). The results demonstrate that CSGP acts as a highly effective, multifunctional ingredient that enhances texture, stability, probiotic viability, and antioxidant capacity, making it a strong clean-label candidate for developing high-quality, functional probiotic low-fat yogurt. Full article

Microbial toxicity tests in the rhizosphere play an important role in the risk assessment and phytoremediation of chemical compounds in the environment. Tests for the inhibition of nodule number (NN), Rhizobia in the rhizosphere (RhR), Rhizobium in nodules (RhN) and arbuscular mycorrhizal fungi (AMFs) are important to evaluate the toxicity as well as the removal of total petroleum hydrocarbons (TPHs), 15 linear alkanes (LAs), and total linear alkanes (TLAs). The inhibition and removal was evaluated at 60 (vegetative stage, VS) and 154 days (reproductive stage, RS) of the life cycle of Crotalaria incana and Crotalaria pallida in soil with four doses of CRO (3, 15, 30, and 45 g/kg) plus a control (16 treatments). Results indicated that RhN and five structures of the AMFs present an index of toxicity (IT < 1), and the microbiological variable is inhibited by the CRO. RhR exhibits a hormesis index (IT > 1) that is stimulated by the CRO in the VS and RS for C. incana and C. pallida. The highest removal of TPHs (77%) was in the rhizosphere of C. incana in the RS with 45 g/kg of CRO. C. pallida removed the greatest amount of TLA (91%). There was a positive correlation between the RhR and the removal of TPHs, TLA, and LAs (higher molecular weight). It could be argued that symbiotic microorganisms are significant for use in toxicity testing, and the rhizosphere of C. incana and C. pallida can be used for the phytoremediation of HTPs and ALs in loamy-clay soil contaminated with CRO. Full article

In this study, dextran-based hydrogels were synthesized in dimethyl sulfoxide via free-radical polymerization with three structurally different crosslinking agents: divinyl benzene (DVB), diethylene glycol diacrylate (DEGDA), and 4,4′-di(methacryloylamino)azobenzene (DMAAazoB). Their morphology, swelling ability, mechanical properties, and potential for controlled release of the model substance (uracil) were examined, with the results showing that the chemical structure and chain length of the crosslinking agents significantly influence the structural and functional properties of hydrogels. Hydrogels crosslinked with DMAAazoB showed the highest swelling ability at pH 3 and pH 6 (2552 and 1696%, respectively), associated with protonation effects and sponge-like morphology, while simultaneously showing the lowest mechanical strength (20 and 47 MPa). In vitro simulations of gastrointestinal digestion showed that uracil was not released in the gastric phase, while in the intestinal environment, the release was significant, especially in Dex-DMAAzoB hydrogels (88.52%). The absence of azoreductases in the simulated system indicates that the release of the drug in real conditions would likely be even more pronounced. The Dex-DAAazoB hydrogel exhibited a slight antibacterial effect, producing inhibition zones of 8 and 7 mm against Escherichia coli ATCC 8739 and Staphylococcus epidermidis ATCC 12228, respectively. In contrast, the remaining hydrogel formulations showed no detectable antibacterial activity toward either bacterial strain, indicating their microbiological inertness and supporting their suitability as carrier matrices for antitumor drug delivery in colorectal cancer therapy. The obtained results confirm that azo-crosslinked dextran hydrogels, with an optimized amount of crosslinking agent, are promising carriers for the targeted and controlled delivery of antitumor drugs to the colorectal region. Full article