Search Results (2,373)

Fiber-degrading microorganisms are widely recognized for their potential to convert renewable lignocellulosic biomass into animal feed. However, translating this potential into practical application faces five critical yet underappreciated challenges. First, current screening methods, primarily including plate dilution and Congo red staining, are low-throughput, poorly reproducible and fail to capture the synergistic actions of natural microbial consortia. Second, the lack of standardized assays for quantifying cellulolytic activity compromises the reliability of cross-study comparisons. Third, safety assessments for fiber-degrading microorganisms remain superficial, with most studies neglecting mycotoxin production, antibiotic resistance gene transfer and long-term colonization risks. Fourth, fundamental differences between fungal and bacterial degradative systems, such as enzyme multiplicity, oxygen requirements and cellulosome assembly, are rarely considered in strain selection, leading to suboptimal application outcomes. Finally, the vast majority of positive in vitro degradation results fail to translate into improved animal performance in vivo, owing to poor microbial survival in the gastrointestinal tract, mismatched enzyme activity with gut pH and temperature, coupled with the absence of dose–response validation. This review critically evaluates these five bottlenecks across fiber-degrading microorganism types, screening platforms and practical livestock production applications. Overall, future progress should depend less on discovering “novel” strains and more on establishing standardized screening pipelines, rigorous safety frameworks and mechanistic understanding of in vivo efficacy, including direct head-to-head comparisons between fungal enzymes and bacterial probiotics under identical conditions. Full article

Honeybee colonies are affected by bacterial, fungal, viral, microsporidian, and parasitic diseases that impair brood viability, adult survival, productivity, and beekeeping sustainability. Conventional control relies on sanitary measures, antibiotics where permitted, and synthetic acaricides, but these approaches are constrained by residues, resistance, regulation, and variable field performance. This narrative review critically evaluates essential oils as alternative or complementary tools against American foulbrood, European foulbrood, varroosis, nosemosis, chalkbrood, and mite-associated viral pressure. Evidence indicates that thymol, carvacrol, eugenol, cinnamaldehyde, and related constituents can show marked antibacterial, antifungal, acaricidal, antioxidant, and host-supportive activity under controlled conditions. However, most bacterial, fungal, and nosemosis data remain laboratory-based, and direct antiviral applications against honeybee viruses are not field validated. The strongest practical evidence concerns thymol-based control of Varroa destructor, where efficacy depends on formulation, release rate, temperature, colony status, and safety margins. Essential oils should therefore be considered components of integrated honeybee health management, not substitutes for established measures. Future studies should prioritize chemical standardization, dose–response testing, colony-level trials, brood and queen safety, sublethal behavior and physiology, gut microbiota, residues, and reproducible delivery systems. Full article

Paraquat is a widely used herbicide known to adversely affect honeybee physiology; however, its impact on gut-associated biological processes remains poorly understood. Therefore, intricate effects of paraquat on honeybees highlight the need for a comprehensive understanding of its specific biological consequences. This study aimed to evaluate the gut microbiome composition and metabolomic profiles of honeybees following oral exposure to sublethal (LD₂₅) and toxic (LD₅₀) doses of paraquat, assessed 48 h post-exposure to represent acute exposure. Survival rate and sucrose consumption were monitored to assess toxicity. Honeybee gut samples were analyzed using 16S rRNA gene amplicon sequencing and metabolomic approaches. Both paraquat treatments resulted in increased mortality (p < 0.0001) and reduced sucrose consumption (p = 0.00503). In contrast, gut bacterial community composition remained largely unchanged (p > 0.05). Metabolomic analysis revealed dose-dependent alterations, particularly in metabolites associated with carbohydrate and energy metabolism, including oxaloacetic acid and pyruvic acid. This study provides the first integration of 16S rRNA gene amplicon sequencing and metabolomic analyses to evaluate the effects of paraquat exposure in honeybees. The findings indicate that paraquat-induced stress primarily exhibits as host metabolic reprogramming rather than changes in microbiome composition. These results provide insights into the mechanisms underlying honeybee responses to herbicide stress and may contribute to the development of strategies for honeybee protection. Full article

The treatment of intracellular bacterial infections such as Chlamydia remains a significant clinical challenge due to rising antibiotic resistance and persistent, immunopathology-driven tissue damage. Macrophages are essential for host defense; they can originate from both tissue-resident precursors and circulating monocytes. During infection, macrophages at infected sites are largely derived from monocytes that migrate and differentiate there, where they phagocytose pathogens and orchestrate immune responses. The chemokine receptor CCR2 is a key regulator of this process, yet its role beyond monocyte trafficking is not fully understood. Previous studies have shown that CCR2 deficiency impairs monocyte mobilization and exacerbates disease during Chlamydia infection, shifting immune responses away from protective Th1 immunity toward pathological Th2 and Th17 polarization. Here, we investigate how CCR2 regulates macrophage function to balance protective Th1 versus pathological Th2/Th17 immunity during Chlamydia respiratory infection. Our results show that CCR2 deficiency reduces pulmonary infiltration of Ly6C^hi and Ly6C^low monocytes and shifts macrophage differentiation away from an M1-like toward an M2-like phenotype. Mechanistically, CCR2 deficiency compromises macrophage endocytosis and survival, elevates ROS production, and activates the NLRP3 inflammasome, leading to Caspase-3/GSDME-mediated pyroptosis with increased IL-1β and IL-18, while suppressing the Caspase-1/GSDMD pathway. These findings were recapitulated in vitro using C. muridarum-stimulated Ccr2-deficient bone marrow-derived macrophages (BMDMs), which also showed impaired migration, reduced M1-like polarization, diminished endocytosis, and enhanced ROS/NLRP3/pyroptosis. Furthermore, co-culture of these BMDMs with CD4⁺ T cells revealed that Th1 differentiation was inhibited, whereas Th2 and Th17 responses were promoted. Collectively, CCR2 orchestrates monocyte–macrophage function by driving M1-like polarization and inhibiting NLRP3/Caspase-3/GSDME pyroptosis to rebalance Th1/Th2/Th17 immunity, thereby enhancing bacterial clearance while mitigating immunopathological tissue damage during Chlamydia infection. Full article

Objectives: A customizable 3D-bioprinted core-in-shell platform was developed for time-dependent oral colon delivery of live microorganisms. The system conveyed Lacticaseibacillus paracasei as a model bacterial species within a monolithic core, which was surrounded by a swellable hydroxypropyl cellulose barrier, imparting a lag phase of programmable duration, and by an enteric outer layer, protecting the dosage form during unpredictable gastric residence. Methods: Pastes of different compositions were investigated to shape the core. Core and core-in-shell units were fabricated from digital models using a bioprinter equipped with a high-precision plunger dispenser and pressure-based thermoplastic printhead. The printed units were characterized in terms of mass, dimensions, mechanical properties and release performance using paracetamol as a reference tracer. Bacterial viability was evaluated during screening of the formulation components and after each processing step by manual counting of colony-forming units. Results: A mannitol-based formulation was selected for fabrication of the core, offering a favorable balance of printability, physico-technological properties, release behavior and ability to preserve bacterial viability. Two-layer core-in-shell systems were manufactured via a dual-printing operating mode. The desired in vitro performance was attained, with no release under acidic conditions, a lag phase in pH 6.8 fluid and a subsequent release profile comparable with that generated by the core as such. Viability studies demonstrated that compounding, core printing, shell deposition and drying did not adversely affect L. paracasei survival. Conclusions: 3D bioprinting was proved to be a versatile technique for the manufacturing of oral colon delivery systems containing probiotics or live biotherapeutics. Full article

To address the industrialization limitations of traditional sourdough and develop high-performance direct-vat-set (DVS) starters for steamed buns, this study screened superior lactic acid bacteria (LAB) and optimized the preparation technology of freeze-dried bacterial powder. The results demonstrated that the compound system of Lactiplantibacillus plantarum and Streptococcus thermophilus at a 1:1 ratio achieved favorable synergistic fermentation with sourdough, which effectively regulated dough acidification and improved the comprehensive sensory quality of steamed buns. The critical processing parameters, including centrifugation conditions and compound lyoprotectant composition containing trehalose, lactose and skim milk powder, were systematically optimized to significantly enhance the freeze-drying survival ability of compound LAB, and the high fitting degree of the established regression model confirmed the stability and reliability of the optimized formulation. The optimal dosage of freeze-dried DVS powder was verified to rationally modulate dough acidity and comprehensively promote the specific volume, structural characteristics and sensory performance of steamed buns. This systematic study provides robust theoretical and technical support for the industrial application of DVS LAB starters in high-quality steamed bun production, facilitating the modernization of traditional fermented wheat products. Full article

Background: Brucellosis is a global zoonosis caused by Brucella. Histidine biosynthesis is essential for bacterial growth, but its role in Brucella melitensis virulence remains unclear. HisD catalyzes the final two steps of histidine synthesis and is absent in mammals, making it a potential drug target. Results: We constructed a hisD deletion mutant (ΔhisD) and complemented strain (ChisD) via homologous recombination. ΔhisD failed to grow in medium without histidine supplementation. It showed reduced survival under polymyxin B and SDS stress, and impaired outer membrane integrity under polymyxin B challenge, though no defect was observed under non-stressed conditions. Intracellularly, ΔhisD replicated poorly in HeLa and RAW264.7 cells, and this defect was rescued by exogenous histidine. In a mouse model, ΔhisD exhibited lower bacterial loads in liver and spleen, reduced splenomegaly, and attenuated hepatic granuloma formation. Conclusions: Histidine biosynthesis deficiency attenuates Brucella virulence by restricting nutritional acquisition and conditionally compromising outer membrane stability. HisD is a promising target for anti-brucellosis drug development, and ΔhisD holds potential as a live attenuated vaccine candidate. Full article

Phage therapy is increasingly recognized as a promising alternative to antibiotics for controlling bacterial diseases in aquaculture. This review focuses specifically on sea cucumber farming, with emphasis on phage application methods, therapeutic performance, and current limitations in translating laboratory results into field use. Available studies show that phage-based treatments can improve the survival of Apostichopus japonicus challenged with Vibrio spp., especially when delivered through feed or formulated as phage cocktails. However, practical application is still constrained by host-range specificity, phage resistance, environmental stability, delivery efficiency, and regulatory barriers. By summarizing recent evidence and identifying research gaps, this review highlights the potential of phage therapy as a sustainable disease management strategy for sea cucumber aquaculture. Full article

Background: Dental caries is a chronic disease mediated by biofilm, which is caused by Streptococcus mutans, and enamel genetics modulates susceptibility. The variants of ENAM might alter the adhesion of enamel and bacteria. One important anti-viral target is sortase A (SrtA), which restricts colonization but does not have an impact on bacterial survival. Aim: The aim of this study was to find out the relationship between ENAM rs3796704 and dental caries vulnerability among adult Iraqi Arab females and to assess the antibiofilm capacity of eugenol and cinnamic acid against S. mutans SrtA using molecular docking, ADMET prediction, and molecular dynamics modeling. Methods: A case–control study was done on 240 women (aged 25–30 years; 120 caries, 120 controls). HRM real-time PCR was done to genotype ENAM rs3796704. An analysis of allelic and genotypic distributions was done using chi-square tests and odds ratios (p < 0.05). An in silico docking analysis aimed at SrtA (PDB: 4TQX) was performed in AutoDock Vina, and this was followed by ADMET profiling and a 50 ns molecular dynamics simulation (OPLS4/TIP3P, NPT 300 K/1 atm). Results: The level of the G allele was found to be lower in the cases than in the controls (60% vs. 70; OR = 0.6429; p = 0.02), but the level of the A allele was found to be higher in the cases (40% vs. 30; OR = 1.5556; p = 0.02). Docking showed a minor difference in binding affinities with eugenol (−4.961 kcal/mol) and cinnamic acid (−4.939 kcal/mol) as compared with chlorhexidine (−4.692 kcal/mol). Both compounds showed stable binding for more than 50 ns as well as desirable predicted pharmacokinetics. Conclusions: The caries vulnerability in this sample was associated with ENAM rs3796704. Eugenol and cinnamic acid undergo stable dissociative interactions with SrtA and were found to have favorable safety profiles in silico. Therefore, they may be considered as adjunctive anti-virulence agents in the prevention of caries. Full article

Antibiotic resistance and biofilm-associated infections require sustainable antimicrobial platforms that combine efficacy with biocompatibility. Fermented matrices are attractive for green nanomaterial production because they provide reducing metabolites and surface-active capping compounds. Rooibos kombucha is a polyphenol-rich fermentation system with potential to serve as a biosynthetic matrix for silver nanoparticles (AgNPs). The present work aimed to develop a rooibos kombucha-enabled platform for the green biosynthesis of phytochemical-capped silver nanoparticles, AgNPs-K, and evaluate their antibacterial, antibiofilm, and in vivo activity. Rooibos kombucha was fermented for 14 days and profiled by liquid chromatography–tandem mass spectrometry (LC–MS/MS). AgNPs-K were generated using kombucha extract and AgNO₃, purified, and characterized by ultraviolet–visible spectroscopy (UV–Vis), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and nanoparticle tracking analysis. Antibacterial activity against eight Gram-positive and Gram-negative reference pathogens was assessed by EUCAST-based microdilution and time-kill assays. Biofilm inhibition was measured by the crystal violet assay. In vivo toxicity and therapeutic efficacy were evaluated in Galleria mellonella larvae. AgNP formation was confirmed by a surface plasmon resonance (SPR) peak at 415 nm. TEM showed predominantly spherical nanoparticles with a main size range of 20–30 nm, a hydrodynamic diameter of 98 nm, and a zeta potential of −14.62 ± 0.04 mV. AgNPs-K showed overlapping minimum inhibitory concentration and minimum bactericidal concentration values of 1.14 µg/mL for Gram-positive species and 1.33 µg/mL for Gram-negative species. Time-kill assays showed rapid bactericidal activity after threshold concentrations were reached, with sustained suppression at 24 h. Biofilm formation was abolished at 40 µg/mL and strongly reduced at lower concentrations. AgNPs-K were non-toxic up to 400 µg/mL and improved survival in six of seven infection models. Fermented rooibos kombucha functions as an effective biosynthetic matrix for the green production of phytochemical-capped AgNPs. The resulting nanoparticles combine low-dose antibacterial and antibiofilm activity with favorable in vivo tolerability and efficacy, supporting fermentation-enabled nanobiotechnology strategies against biofilm-associated infection. Full article

Massilia varians has potential as a probiotic to inhibit bacterial pathogens in aquaculture, but very limited information is available regarding its use in Chinese mitten crab Eriocheir sinensis for enhancing host immunity, antioxidant ability and intestinal microbiota homeostasis. In this study, a 40-day feeding trial was conducted to evaluate the protective effects of dietary supplementation with M. varians P2-4 on nonspecific immune response, antioxidant status, intestinal microbiota and resistance against Pseudomonas aeruginosa infection in E. sinensis. Results demonstrated that dietary supplementation with M. varians P2-4 at 6.0 × 10⁶ to 6.0 × 10⁸ CFU/g diet significantly boosted nonspecific immunity and improved antioxidant capability of E. sinensis, mainly as evidenced by markedly increased activities of plasma lysozyme, plasma superoxide dismutase, hepatopancreatic superoxide dismutase and catalase. Furthermore, crabs fed M. varians P2-4-supplemented diets exhibited markedly improvements in intestinal microbiota composition and diversity, and showed substantially enhanced survival following P. aeruginosa challenge, with 7-day relative percentage survival ranging from 76.9% to 100.0%. To the best of our knowledge, this is the first study to reveal that M. varians P2-4 supplementation functions as a new biocontrol strategy in E. sinensis by effectively improving the non-specific immunity, antioxidant status and intestinal microbiota to mitigate P. aeruginosa infection. Full article

Carbapenem-resistant Acinetobacter baumannii (CRAB) is considered a persistent clinical problem characterized by high mortality and restricted therapeutic options. The current antimicrobial regimen focuses on active bacteria without taking into account physiological states that influence the treatment response. Biofilm formation, metabolic changes, efflux activity, and membrane remodeling reduce antibiotic activity at infection sites and help bacteria survive despite in vitro susceptibility. Clinical performance is also compromised by inadequate tissue penetration, toxicity, and inconsistent pharmacokinetics, which reduce the ability to maintain effective antimicrobial activity at the target site. Therefore, a new strategy is needed that considers how bacteria behave during infection. Nanotherapeutic systems can optimize antimicrobial delivery by changing drug distribution and enabling sustained antimicrobial release within infected tissues. These properties can improve antimicrobial distribution within biofilms and structurally restricted infection sites. This review proposes a phenotype-guided approach linking dominant bacterial phenotypes with targeted nanotherapeutic intervention. Advances in nanoscale diagnostics and computational analysis allow earlier identification and more precise characterization of resistance features, so treatment decisions reflect the current state of infection. When integrated with nanotechnology, this information supports treatment approaches that adapt to changes in bacterial behavior over time. Extending this concept to host-directed and microbiome-informed interventions provides additional control by addressing factors that sustain infection beyond the pathogen. These elements create an integrated system that connects detection, analysis, and treatment, allowing therapy to match the biological conditions of infection for more precise CRAB management. Full article

This study reports, for the first time, changes in the microbiome community associated with anhydrobiosis in two tardigrade species of the genus Paramacrobiotus. To identify bacteria linked to the anhydrobiosis phenomenon and to track microbiome changes under anhydrobiotic stress, next-generation sequencing of bacterial 16S rRNA genes was conducted. Microbiome profiling was performed across various developmental and physiological stages of tardigrades, including: eggs; active adult specimens (both before and after 7, and 120 days of anhydrobiosis, referred to as short- and long-term anhydrobiosis, respectively); specimens in the desiccated tun stage; dead specimens following long-term anhydrobiosis (no dead specimens were observed after short-term anhydrobiosis); and the culture medium. It was shown that the microbiome community varied among stages, with high stage-specificity. Several bacterial genera were identified that may assist the host during anhydrobiosis, potentially through biofilm formation and by supporting stress-protective mechanisms such as heat shock protein expression and trehalose synthesis in eggs and tuns. These findings reveal that microbiota may contribute to anhydrobiotic survival in tardigrades, providing novel insights into host–microbe interactions under extreme environmental stress. Full article

Streptococcus pneumoniae is a leading cause of community-acquired pneumonia, yet the immune mechanisms required for protection against invasive pulmonary infection remain inadequately understood. Using a murine model of homologous protection against invasive pneumococcal pneumonia, we explored the relative contributions of humoral and cellular immunity using adoptive serum transfer, immune cell depletion, and lung transcriptional profiling. Our findings indicated that passive transfer of immune serum provided robust protection, while neutrophil depletion significantly compromised bacterial control, highlighting that both antibodies and neutrophils are key mediators of protection. In contrast, depletion of CD4⁺ T cells or NK cells did not compromise survival. Although IL-17A has been widely implicated in host defense against pneumococcal infection, IL-17A-deficient mice remained protected, albeit with delayed clearance and reduced early antibody responses. We associate this delay with compensatory upregulation of IL-17F and increased expression of Th1-associated genes in the lungs. Together, these findings indicate that IL-17A is not essential for protection and support a model in which coordinated Th1- and Th17-related cytokine responses collectively promote neutrophil recruitment and effective antibody-mediated defense. These results highlight functional redundancy within the IL-17 cytokine axis and suggest that integrated cytokine networks, rather than individual mediators, underpin protective immunity to pneumococcal pneumonia, with implications for next-generation vaccine design. Full article

Mori Cortex Radicis (MCR), which is abundant in resources and low in cost, is a Chinese herbal medicine with antitussive, anti-inflammatory, analgesic, and hypoglycemic effects; however, its application in the prevention and control of aquatic pathogens remains understudied. In this study, a MCR water extract (MCR-WE) was prepared, and its contents of polysaccharides, polyphenols, and proteins were found to be 0.63%, 1.17%, and 2.79%, respectively. LC-MS metabolomics revealed that L(+)-Arginine, 9,12,13-Todea, Citric acid, 1-Deoxynojirimycin, and 4-Guanidinobutanoic acid were the most abundant compounds. Subsequently, by feeding the MCR-WE to crucian carp (Carassius auratus) and challenging them with Aeromonas veronii, it was found that the MCR-WE enhanced the activities of immune factors (AKP, ACP, LZM) and the phagocytic activity of leukocytes (p < 0.05). Furthermore, the MCR-WE improved the survival rate of crucian carp (p < 0.05), reduced the bacterial load in the kidneys (p < 0.05), decreased the mRNA expression of inflammatory factors (IL-6, IL-1β, TNF-α), and lowered the expression levels of antioxidant-related factors (CAT, GSH-Px, SOD, MDA) and the mRNAs of oxidative stress pathway factors (Nrf2, HO-1, Keap1) (p < 0.05). Histopathological sections and immunofluorescence assays showed that the MCR-WE maintained the structural integrity of internal organs and reduced renal cell apoptosis and DNA damage. Therefore, MCR-WE is rich in immunologically active substances, can activate the immune response of crucian carp, reduce fish mortality, exert anti-inflammatory and antioxidant activities, and maintain the structural and functional integrity of internal organs. Thus, the MCR-WE holds promise as a therapeutic agent against A. veronii infection in fish. Full article