Search Results (4,263)

In recent years, the rise in food allergies and intolerances, combined with the increasing consumer preference for healthier, plant-based alternatives to traditional dairy products, has driven the development of a diverse range of plant-based beverages. Among these, tree nut-based beverages, “ready-to-drink” products made from nuts such as almonds, hazelnuts, pistachios, walnuts, brazil nut, macadamia, cashew nut, coconut, pine nut, have gained significant popularity. This review offers a comprehensive analysis of the microbiological, nutritional, and sensory properties of tree nut-based beverages, highlighting their ability to deliver essential nutrients such as healthy fats, proteins, fiber, vitamins, and minerals. Additionally, these beverages provide a rich source of bioactive compounds (e.g., antioxidants, polyphenols) that can contribute to health benefits such as reducing oxidative stress, supporting cardiovascular health, and promoting overall well-being. The review also highlights the ability of different species of lactic acid bacteria to enhance flavour profiles and increase the bioavailability of certain bioactive compounds. Nevertheless, further research is essential to optimize the production methods, improve sensory characteristics, and address challenges related to cost, scalability, and consumer acceptance. Continued innovation in this area may position tree nut beverages as a key component of plant-based food models, contributing to the promotion of healthier eating patterns. Full article

Alphaviruses are transmitted by Aedes mosquitoes and cause large-scale epidemics worldwide. Chikungunya virus (CHIKV) infection can cause febrile seizures known as chikungunya fever (CHIKF), which ultimately leads to severe joint pain and myalgia. While a vaccine has recently been introduced against CHIKV, at present, no anti-viral drug is available. CHIKV, like other alphaviruses, has a short 6K protein capable of forming an ion channel. Blocking this ion channel with drugs can therefore serve as a potential way to curtail CHIKV infection. To that end, we screened a repurposed drug library using three bacteria-based channel assays to detect blockers against 6K viroporin, yielding several hits. Interestingly, several of the blockers were able to inhibit the 6K protein from the similar Eastern equine encephalitis virus (EEEV), while others were not, pointing to structural specificity which may be explained by modeling studies. In conclusion, our study provides a starting point for developing a new route to potentially inhibit CHIKV. Full article

Antimicrobial resistance (AMR) is traditionally discussed in the context of horizontally acquired resistance genes and point mutations at target loci. However, this gene-centred model fails to account for a large number of clinically important modalities of resistance. There is now substantial evidence implicating bacteria in the ability to escape the effects of antibiotics in a variety of non-canonical ways, which are not considered in traditional diagnostic and surveillance pipelines. Among these factors, we can list those arising from global regulatory networks, phase variability, epigenetic tuning, small RNAs, genome structural variability, and phenotypic states like tolerance and persistence. This review will blend the current knowledge on these alternative pathways of resistance and underscore how they intersect with canonical genetic determinants. We will highlight cases where resistance emerges in the absence of known resistance genes, analyse the role of regulatory plasticity in efflux pump expression and membrane remodelling, and examine the contributions of bacterial stress responses and post-transcriptional control. Additionally, we will address methodological gaps in the detection of these mechanisms and their implications for clinical treatment failure, resistance surveillance, and drug development. By integrating insights from molecular microbiology, systems biology, and genomics, this review aims to offer a framework for understanding AMR as a multifaceted, context-dependent phenotype, not merely a genotype. We conclude by identifying knowledge gaps and suggesting priorities for research and diagnostic innovation in this evolving field. Full article

Background: Urinary tract infections (UTIs) are among the most common hospital- and community-acquired infections, creating a substantial healthcare burden due to recurrence, complications, and rising antimicrobial resistance. Accurate diagnosis and timely antimicrobial therapy are essential. This study aimed to identify trends in the etiology, treatment, and resistance patterns of UTIs through a retrospective analysis of urine isolates processed at the Laboratory of Microbiology at University Hospital St. George in Plovdiv, the largest tertiary care and reference microbiology center in Bulgaria, between 2017 and 2022. Materials and Methods: A retrospective single-center study was performed at the hospital’s Microbiology Laboratory. During the study period, 74,417 urine samples from 25,087 hospitalized patients were screened with the HB&L UROQUATTRO system. Positive specimens were cultured on blood agar, Eosin-Methylene Blue, and chromogenic media. Identification was performed using biochemical assays, MALDI-TOF MS, and the Vitek 2 Compact system. Antimicrobial susceptibility testing included disk diffusion, MIC determination, broth microdilution (for colistin), and Vitek 2 Compact, interpreted according to EUCAST standards. Descriptive analysis and temporal resistance trends were evaluated with regression models, and interrupted time-series analysis was applied to assess COVID-19-related effects. Results: Out of 10,177 isolates, Gram-negative bacteria predominated (73%), with Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis as the leading pathogens. Among Gram-positives, Enterococcus faecalis was the most frequent. In the post-COVID-19 period, ESBL production increased in E. coli (34–38%), K. pneumoniae (66–77%), and P. mirabilis (13.5–24%). Carbapenem resistance rose in K. pneumoniae (to 40.6%) and P. aeruginosa (to 24%), while none was detected in E. coli. Colistin resistance increased in K. pneumoniae but remained absent in E. coli and P. aeruginosa. High-level aminoglycoside resistance in E. faecalis was stable (~70%), and vancomycin resistance in E. faecium rose from 4.6% to 8.9%. Conclusions: Both community- and hospital-acquired UTIs in Southeastern Bulgaria are increasingly linked to multidrug-resistant pathogens, particularly ESBL-producing and carbapenem-resistant Enterobacterales. Findings from the region’s largest referral center highlight the urgent need for continuous surveillance, rational antibiotic use, and novel therapeutic approaches. Full article

Gut microbiota has increasingly been shown to exert effects beyond the gastrointestinal tract, some of which are mediated through its metabolites, such as trimethylamine N-oxide (TMAO)—a compound converted by gut bacteria from dietary choline found predominantly in animal products that is associated with cardiovascular disease (CVD). However, a significant gap persists in human clinical trials assessing its potential causal role. This narrative review aims to present the current understanding of the gut microbiome, TMAO, and their relationship with CVD, while proposing future directions that may support the use of TMAO as a biomarker and guide potential interventions to reduce its harmful impact. Both animal and human studies have demonstrated a link between TMAO and CVD, with animal studies also indicating a causal effect—showing increased cardiovascular risk following TMAO administration and reduced risk when TMAO is eliminated. While direct extrapolation from animal models to humans is limited due to biological differences, these findings offer a foundation for the development of well-designed clinical trials in human populations. Although direct approaches to target TMAO—such as trimethylamine (TMA) lyase inhibitors and antisense oligonucleotide (ASO) therapy—have shown promising results in animal studies, they have yet to be investigated in human trials, leaving indirect strategies such as dietary changes and probiotics as the only currently available options. Full article

This study evaluated the effectiveness of photodynamic treatment (PDT) using riboflavin (Rbf) and blue light-emitting diode (BL) irradiation for microbial inactivation and quality preservation in fresh betel leaves (Piper betle L.). Non-pathogenic surrogates Escherichia coli K-12 and Listeria innocua were used to model Gram-negative and Gram-positive bacteria. The combined Rbf-BL treatment significantly reduced microbial populations by up to 5.3 log CFU/g for E. coli and 6.2 log CFU/g for L. innocua on leaf surfaces (p < 0.05) and 1.3–1.5 log CFU/mL in broth cultures. Treated samples showed significantly higher total soluble solids (12.0 ± 0.0 °Brix), total phenolic content (0.17 ± 0.02 mmol GAE/g, p < 0.05), and antioxidant activity (62.0 ± 3.1% DPPH inhibition, p < 0.05), with minimal color alteration after treatment (ΔE = 4.68). The total fluence measured at the leaf surface was approximately 11.72 J/cm². As a mild thermal treatment utilizing a GRAS photosensitizer, riboflavin-assisted PDT presents a promising strategy for enhancing microbial safety and promoting phytochemical quality in betel leaves. Full article

Background/Objectives: Infant diarrhea is a major global cause of morbidity and mortality. While Bifidobacterium is linked to diarrhea, its preventive effects, underlying mechanisms, and potential synergistic benefits with prebiotics remain unclear. The objective of this study was to explore the efficacy of a synbiotic composed of Bifidobacterium animalis subsp. lactis BB-12 (BB-12) and 2′-fucosyllactose (2′-FL) in alleviating infant diarrhea. Methods: One-week-old C57BL/6J mice were used to construct a model of infant diarrhea via infection with enteropathogenic Escherichia coli (EPEC) O127. Mice were administered BB-12 (10⁸ CFU per mouse), 2′-FL (1 g/kg), or their combination (synbiotic) for three consecutive weeks. Results: Administration of the synbiotic not only markedly improved diarrhea, anxiety-like behavior, colon inflammation, and gut barrier function but also positively reshaped the microbial community. This was achieved through a significant rise in short-chain fatty acid (SCFA)-producing bacteria (e.g., Akkermansia and Paraprevotella), a rise in fecal SCFAs, and a reduction in harmful bacteria such as Escherichia. Conclusions: The synbiotic effectively relieves EPEC-induced infant diarrhea by regulating gut microbiota composition and metabolic functions. These findings highlight its potential as a dietary intervention in infant diarrhea and provide new insights into infant health applications. Full article

In this work, redox-responsive chitosan derivatives were prepared by crosslinking with disulfide-bridged dicarboxylic acids. Taking into account that structural variations in diacids can lead to significant differences in properties, especially swelling capacity, this study aimed to evaluate the impact of increasing alkyl chain length and hydrophobicity. Two dicarboxylic acids of different hydrophobic character and chain length were used: dithiodiglycolic acid (DTGA) and dithiopropionic acid (DTPA). The resulting materials were fully characterized. Despite their structural similarity, the derivatives exhibited distinct behaviors: DTGA derivatives formed stable hydrogels, whereas DTPA ones remained compact upon contact with water. These results were confirmed by swelling measurements and oscillatory rheology. The EDC:COOH molar ratio was also evaluated, revealing a strong effect on the degree of crosslinking. Moreover, DTGA systems prepared at a 1:1 ratio showed significantly higher swelling than those synthesized at 3:1. Regarding redox responsiveness, it was assessed by quantifying thiol content before and after reduction with sodium borohydride, and reversibility was assessed through reduction–oxidation cycles. Finally, preliminary experiments evaluated the materials’ ability to incorporate benzalkonium chloride as a model biocide, and their release was tested in the presence of thiosulfate-reducing bacteria, providing initial insight into their behavior in redox-responsive delivery systems. Full article

Background: The human gut microbiome—a diverse ecosystem of trillions of microorganisms—plays an essential role in metabolic, immune, and neurological regulation. However, modern lifestyle factors such as antibiotic overuse, cesarean delivery, reduced breastfeeding, processed and high-sodium diets, alcohol intake, smoking, and exposure to environmental toxins (e.g., glyphosate) significantly reduce microbial diversity. Loss of keystone species like Bifidobacterium infantis (B. infantis) and Lactobacillus reuteri (L. reuteri) contributes to gut dysbiosis, which has been implicated in chronic metabolic, autoimmune, cardiovascular, and neurodegenerative conditions. Materials and Methods: This Qualitative Systematic Review (QualSR) synthesized data from over 547 studies involving human participants and standardized microbiome analysis techniques, including 16S rRNA sequencing and metagenomics. Studies were reviewed for microbial composition, immune and metabolic biomarkers, and clinical outcomes related to microbiome restoration strategies. Results: Multiple cohort studies have consistently reported a 40–60% reduction in microbial diversity among Western populations compared to traditional societies, particularly affecting short-chain fatty acid (SCFA)-producing bacteria. Supplementation with B. infantis is associated with a significant reduction in systemic inflammation—including a 50% decrease in C-reactive protein (CRP) and reduced tumor necrosis factor-alpha (TNF-α) levels—alongside increases in regulatory T cells and anti-inflammatory cytokines interleukin-10 (IL-10) and transforming growth factor-beta 1 (TGF-β1). L. reuteri demonstrates immunomodulatory and neurobehavioral benefits in preclinical models, while both probiotics enhance epithelial barrier integrity in a strain- and context-specific manner. In murine colitis, B. infantis increases ZO-1 expression by ~35%, and L. reuteri improves occludin and claudin-1 localization, suggesting that keystone restoration strengthens barrier function through tight-junction modulation. Conclusions: Together, these findings support keystone species restoration with B. infantis and L. reuteri as a promising adjunctive strategy to reduce systemic inflammation, reinforce gut barrier integrity, and modulate gut–brain axis (GBA) signaling, indicating translational potential in metabolic and neuroimmune disorders. Future research should emphasize personalized microbiome profiling, long-term outcomes, and transgenerational effects of early-life microbial disruption. Full article

This study investigated the isolation and formulation of a bacterial conditioner as a biostimulant for Triticum durum (durum wheat) under salinity stress. An Algerian alkaline–saline soil was sampled, characterized for its physical and chemical characteristics and its culturable and total microbial community (16S rRNA gene metabarcoding). Three bacterial strains showing high 16S rRNA gene similarity to Pseudomonas putida, Bacillus proteolyticus, and Niallia nealsonii were selected for their plant growth-promoting (PGP) traits under different salinity levels, including phosphate solubilisation (194 µg mL⁻¹), hormone production (e.g., gibberellin up to 56 µg mL⁻¹), and good levels of hydrocyanic acid, ammonia, and siderophores. N. nealsonii maintained high indole production under saline conditions, while B. proteolyticus displayed enhanced indole synthesis at higher salt concentrations. Siderophore production remained stable for P. putida and N. nealsonii, whereas for B. proteolyticus a complete inhibition was registered in the presence of salt stress. The consortium density and application were tested under controlled conditions using Medicago sativa as a model plant. The effective biostimulant formulation was tested on Triticum durum under greenhouse experiments. Bacterial inoculation significantly improved plant growth in the presence of salt stress. Root length increased by 91% at 250 mM NaCl. Shoot length was enhanced by 112% at 500 mM NaCl. Total chlorophyll content increased by 208% at 250 mM NaCl. The chlorophyll a/b ratio increased by 117% at 500 mM. Also, reduced amounts of plant extracts were necessary to scavenge 50% of radicals (−22% at 250 mM compared to the 0 mM control). Proline content increased by 20% at both 250 mM and 500 mM NaCl. These results demonstrate the potential of beneficial bacteria as biostimulants to mitigate salt stress and enhance plant yield in saline soils. Full article

The logistic modeling of diauxic growth and biphasic antibacterial activity (AA) production was enhanced for four lactic acid bacteria (Lactococcus lactis CECT 539, Pediococcus acidilactici NRRL B-5627, Lactobacillus casei CECT 4043, and Enterococcus faecium CECT 410) during realkalized fed-batch fermentations. The improved growth model, also validated for describing the diauxic growth of Mos breed roosters and foals, overcomes a key limitation of the bi-logistic model, which assumes the existence of two distinct populations growing from the start of the culture, each following a different growth profile. In contrast, the improved logistic growth model developed in this study accounts for a single population growing at two rates, offering a fit to the experimental data comparable to that of the commonly used bi-logistic model. The enhanced model for product synthesis accurately describes biphasic AA production, assuming that antibacterial products are synthesized as growth-associated metabolites, depending on the final pH reached in the cultures at each sampling time. Additionally, it is easier to apply than the unmodified or modified differential forms of the Luedeking–Piret model. This study demonstrated, for the first time, the applicability of these two models in describing the diauxic growth and biphasic AA synthesis of LAB. Full article

Age-related impaired wounds often become infected with bacteria, leading to substantial mortality and morbidity in the elderly. The decline in androgen levels with increasing age is believed to exacerbate inflammation during wound infections. Despite its well-documented anti-inflammatory activities in wound repair, little is known about the effect of age-related androgen deprivation on bacterial phagocytosis in impaired chronic wounds. The aim of this study was to investigate the effect of age-related testosterone deprivation on the phagocytic functions of THP-1 monocyte-derived macrophages to eliminate Gram-positive and Gram-negative bacteria in vitro. Host–pathogen interaction experiments were conducted to quantify the macrophage-mediated clearance of two common wound-associated bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, under in vitro environments that model testosterone levels representative of those found in elderly males, healthy young adults and testosterone replacement therapy (TRT). Testosterone and its metabolite 5α-dihydrotestosterone (DHT) significantly dampened the macrophage-mediated phagocytosis of both MRSA and P. aeruginosa in a dose-dependent manner (p < 0.05). Blockade of the androgen receptor (AR) using enzalutamide confirmed that testosterone mediates bacterial clearance through binding to the AR. Blocking the conversion of testosterone to DHT through stimulation of macrophages with the 5-α-reductase inhibitor finasteride reversed the testosterone-mediated effects on bacterial clearance, which confirmed that testosterone could potentially dampen the innate phagocytic responses in macrophages through conversion to DHT. Novel findings in this study suggest that the selective manipulation of the AR and/or blockade of testosterone–DHT conversion may provide effective therapeutic treatments to combat wound infections in the elderly. Full article

The continued acidification of red soil reduces phosphorus availability and microbial activity, which restricts corn growth. Phosphorus tailings, a waste product from phosphate mining, can neutralize soil acidity and supply controlled-release phosphorus, but their effects on the red soil-corn system remain unclear. A field experiment in Qujing, Yunnan (2023–2024), tested four treatments: CK (standard fertilization), T1 (CK plus phosphorus tailings), T2 (80% of standard fertilizer plus phosphorus tailings), and T3 (80% of standard fertilizer plus phosphorus tailings and organic fertilizer, both applied at 6.0 t·ha⁻¹). Using high-throughput sequencing, redundancy analysis (RDA), and structural equation modeling (SEM), the study evaluated impacts on soil properties, microbial communities, and corn yield and quality. Results showed: (1) Phosphorus tailings reduced soil acidification; T3 raised soil pH in the top 0–10 cm by 0.54–0.9 units compared to CK and increased total, available, and soluble phosphorus in the 0–20 cm layer to 952.82, 28.46, and 2.04 mg/kg, respectively. (2) T3 exhibited the highest microbial diversity (Chao1 and Shannon indices increased by 177.57% and 37.80% versus CK) and a more complex bacterial co-occurrence network (114 edges versus 107 in CK), indicating enhanced breakdown of aromatic compounds. (3) Corn yield under T3 improved by 13.72% over CK, with increases in hundred-grain weight (+6.02%), protein content (+18.04%), and crude fiber (+9.00%). (4) Effective nitrogen, ammonium nitrogen, available phosphorus, and soil conductivity were key factors affecting gcd/phoD phosphorus-reducing bacteria. (5) Phosphorus tailings indirectly increased yield by modifying soil properties and pH, both positively linked to yield, while gcd-carrying bacteria had a modest positive influence. In summary, combining phosphorus tailings with a 20% reduction in chemical fertilizer reduces fertilizer use, recycles mining waste, and boosts corn production in acidic red soil, though further studies are needed to evaluate long-term environmental effects. Full article

Nucleic acid aptamers are single-stranded DNA or RNA molecules that can bind to a target with high specificity and affinity, as screened by the Systematic Evolution of Ligands by Exponential Enrichment (SELEX). In recent years, SELEX technologies have been significantly advanced for the screening of aptamers for a variety of target molecules, cells, and even bacteria and viruses. By integrating recent advances of emerging technologies with SELEX, novel screening technologies for nucleic acid aptamers have emerged with improved screening efficiency, reduced production costs and enhanced aptamer performance for a wide range of applications in medical diagnostics, drug delivery, and environmental monitoring. Aptasensors utilize aptamers to detect a wide range of analytes, allowing for the accurate identification and determination of small molecules, proteins, and even whole cells with remarkable specificity and sensitivity. Further optimization of the aptasensor can be achieved by aptamer truncation, which not only maintains the high specificity and affinity of the aptamer binding with the target analytes, but also reduces the manufacturing cost. Predictive models also demonstrate the powerful capability of determination of the minimal functional sequences by simulation of aptamer–target interaction processes, thus effectively shortening the aptamer screening procedure and reducing the production costs. This paper summarizes the research progress of protein-targeted aptamer screening in recent years, introduces several typical aptasensors at present, discusses the optimization methods of aptasensors by combining efficient SELEX with advanced predictive algorithms or post-SELEX processes, as well as the challenges and opportunities faced by aptasensors. Full article

(1) Background: This study aimed to determine the optimum parameters for the treatment of Streptococcus mutans biofilm on clear dental aligners. (2) Methods: A 24-h-old S. mutans biofilm was grown on polyurethane (PU) and poly(ethylene terephthalate glycol) (PETG) aligners. These samples were treated with three chlorhexidine digluconate (CHX)-based antiseptic solutions, manual brushing, and a combination of both, with varying exposure times. The number of adhered bacteria was determined in both untreated and treated samples after sonication. Materials were analyzed with atomic force and scanning electron microscopy, and surface free energy (SFE) values were determined using three different models. (3) Results: Our findings indicated that control strategies do not depend on the type of material. PU and PETG surfaces exhibited similar SFE values (41–45 mJ/m²). Differences in surface roughness were insufficient to cause significant changes in S. mutans behavior. The highest efficacy of all three tested antiseptics was established for the exposure time of 1 min, with efficacy deteriorating just after 3 min. (4) Conclusions: The efficacy of CHX against S. mutans early biofilm is material-independent and time-dependent. The optimal exposure time of 1 min should be combined with brushing, with a general recommendation of the antiseptic-first approach. Full article