Search Results (1,449)

Breast cancer is the most frequently diagnosed malignancy among women worldwide, with the luminal A subtype being the most prevalent. Several studies have reported a complex interplay between breast cancer cells and the local microbiome; however, the mechanisms by which tumor cell-secreted factors influence bacterial biological properties remain insufficiently explored. In this study, we established an in vitro model that partially recapitulates the luminal A breast cancer microenvironment by exposing three breast-associated bacterial species, Pseudomonas aeruginosa, Enterococcus faecalis, and Escherichia coli, to conditioned media (CM) derived from MCF-7 (tumor) or MCF-10A (non-tumor control) cell lines. A combination of complementary approaches, including ultrastructural morphological assessment, biofilm formation assays, antimicrobial susceptibility testing, and virulence gene abundance profiling by genomic qPCR, was employed to reveal distinct tumor-microbiota interactions. Exposure to MCF-7 CM induced dose-dependent structural alterations in P. aeruginosa and E. faecalis, with pronounced membrane blebbing and structural disruption in E. faecalis. Biofilm formation was differentially modulated in a species- and concentration-dependent manner, with a persistent increase observed in E. coli. Antibiotic susceptibility profiles were selectively altered in E. faecalis, which displayed increased sensitivity to vancomycin, penicillin, and imipenem, along with decreased sensitivity to chloramphenicol. P. aeruginosa exhibited increased sensitivity to imipenem along with reduced sensitivity to meropenem and gentamicin, whereas no significant changes were observed in E. coli. qPCR analyses demonstrated that MCF-7 CM was associated with enrichment of multiple virulence-associated genes (e.g., lasB, exoS, pilB, plcH, fsrC, esp, fimH, and papG), reflecting enhanced pathogenic and adhesive potential. Collectively, these findings suggest that luminal A breast cancer-derived factors can reprogram microbial phenotypes in a species-specific manner, providing mechanistic insight into breast tumor-microbiome crosstalk and a platform to explore microbiome-targeted interventions. Full article

Drawing on two indigenous chicken breeds that have adapted for centuries to the hyper-arid Tarim Basin, namely the Baicheng You Chicken and Hotan Black Chicken, this study provides a high-resolution map of their gut microbiota across the duodenum, jejunum, ileum and cecum and subsequently isolates putative probiotic strains from cecal contents using conventional culture techniques. In the duodenum, Lactobacillus dominated Hotan Black Chicken (43.16%), whereas Ligilactobacillus prevailed in Baicheng You Chicken (37.03%). This segregation persisted in the jejunum, with Lactobacillus accounting for 62.55% of Hotan Black Chicken reads and Ligilactobacillus accounting for 60.76% reads in Baicheng You Chicken. The ileal core of Hotan Black Chicken remained Lactobacillus (50.63%), while Baicheng You Chicken shifted to Enterococcus (32.37%). In the cecum, both breeds converged on the Rikenellaceae RC9 gut group as the single dominant lineage (Hotan Black Chicken, 46.87%; Baicheng You Chicken, 46.23%). At the genus level, Hotan Black Chicken was enriched in Lactobacillus and Ligilactobacillus, whereas Baicheng You Chicken harbored a greater proportion of Enterococcus. Concurrently, eight strains with in vitro probiotic attributes were isolated, four from each breed, identified as Ligilactobacillus salivarius, Limosilactobacillus reuteri, Lactobacillus gallinarum, Enterococcus lactis, Enterococcus faecium, Enterococcus faecalis, and Bacillus velezensis. This study deciphers the intestinal microbiome of two native Tarim Basin chicken breeds, Hotan Black Chicken and Baicheng You Chicken, and mines them for autochthonous probiotic strains. The obtained dataset has established a foundational resource for poultry-related probiotics adapted to extremely arid environments, providing theoretical insights and practical value for poultry nutritionists in water-scarce regions in the future. Full article

Diabetic foot ulcer (DFU) infections frequently involve biofilm formation and exhibit limited responsiveness to conventional antibiotic therapy. In particular, Pseudomonas aeruginosa often participates in mono- and polymicrobial biofilms that display high tolerance to antimicrobial agents. This study evaluated the efficacy of methylene blue-mediated antimicrobial photodynamic therapy (aPDT), alone and in combination with antibiotics, against P. aeruginosa biofilms formed either as single-species or in mixed communities with Enterococcus faecalis, under conditions mimicking DFU infections. Macrocolony biofilms were challenged with amikacin alone (for single-species biofilms) or amikacin plus ampicillin (for mixed biofilms), aPDT, or sequential combinations of these treatments, and bacterial viability was quantified by colony-forming unit enumeration. Antibiotic treatment alone produced only modest reductions in P. aeruginosa viability, even at high concentrations, while aPDT using methylene blue was effective only at high photosensitizer concentrations. In contrast, sequential treatment with antibiotics followed by aPDT and a second antibiotic challenge resulted in a marked reduction in P. aeruginosa viability in both mono- and polymicrobial biofilms. Scanning electron microscopy revealed extensive structural damage in P. aeruginosa cells following combined treatments, whereas E. faecalis remained unaffected. Overall, our findings demonstrate that combining aPDT with antibiotics significantly enhances antibiofilm activity against P. aeruginosa, highlighting this approach as a promising alternative for the management of biofilm-associated DFU infections. Full article

To explore high-quality phage resources for controlling Enterococcus faecalis (E. faecalis) contamination, a virulent phage vB-Efa1 was isolated and purified from poultry slaughterhouse sewage in this study. Its biological characteristics, whole-genome features, and potential in ensuring poultry product processing safety were systematically investigated. The phage belongs to the Siphoviridae family, with an optimal multiplicity of infection (MOI) of 0.1 and a titer of 8.87 lg PFU/mL; it has a 30 min latent period and stable lytic activity, retaining good stability at 25–37 °C, pH 6–8, and 4 °C. Its circular whole genome is 166,586 bp in length with a GC content of 35.46%, encoding 276 genes; no antibiotic resistance genes were detected, and only one low-pathogenic-risk virulence-related sequence was identified. Application tests in poultry products revealed that temperature is the key factor regulating phage titer: the titer stably maintained 5.5–6.6 lg PFU/mL at 4 °C, while proliferating significantly at 25 °C, reaching 7.55–8.38 lg PFU/mL at 12 h. Collectively, vB-Efa1 exhibits superior biological traits, environmental adaptability, and biosafety, making it a promising biocontrol candidate for mitigating E. faecalis contamination in poultry products. Full article

Background: Poultry-associated Enterococcus spp. are widespread commensals but may serve as One Health indicators when virulence-associated determinants and antimicrobial resistance co-occur. We characterized paired phenotypic and genomic profiles to delineate species-stratified virulome and resistome patterns. Methods: Isolates originated from a previously established poultry collection with MIC testing. Genotype–phenotype analyses were restricted to the whole-genome sequenced subset (n = 31). The acquired antimicrobial resistance genes were identified using the Comprehensive Antibiotic Resistance Database (CARD), and virulence-associated determinants were screened using the Virulence Factors Database (VFDB). Results were summarized as isolate-level presence/absence matrices and integrated with MIC-derived susceptible/intermediate/resistant categories. Results: The WGS subset comprised E. faecalis (n = 23) and E. faecium (n = 8) with diverse sequence types. Virulome architecture was strongly species-dependent: E. faecalis carried a broad repertoire of adhesion/biofilm-associated determinants, whereas E. faecium showed a limited set of high-confidence virulence-associated hits. Acquired resistance determinants were common across isolates, and resistome profiles displayed structured co-occurrence. Integrated analyses suggested only a modest overall association between virulence-gene burden and acquired resistome size, largely driven by species-level differences. Genotype–phenotype concordance was class-dependent, with incomplete alignment in several antimicrobial classes, consistent with mechanisms beyond the screened acquired gene set. The acquired resistance determinants detected in the WGS subset predominantly mapped to antimicrobial classes commonly used in food-producing animals (e.g., tetracyclines, macrolides, lincosamides, aminoglycosides, and phenicols), supporting interpretation in the context of production-associated antimicrobial selection rather than implying last-line clinical resistance by default. Conclusions: Poultry-derived enterococci may combine genetic features compatible with persistence/colonization and acquired antimicrobial resistance, with co-occurrence patterns shaped primarily by species/lineage background. These findings support risk-stratified One Health surveillance and targeted functional and mechanism-focused follow-up. This integrated virulome–resistome view highlights species-specific risk signatures in poultry-associated Enterococcus and identifies discordant high-level phenotypes that merit targeted mechanistic follow-up. Full article

Spent coffee grounds (SCGs), as a by-product, represent a sustainable source of bioactive components. Herein, the ethanol extract of SCGs was examined for its chemical characteristics and antimicrobial effect. The extract was incorporated into novel frankincense-based gums at concentrations of 0% (T0), 15% (T15), 20% (T20), and 25% (T25). The physicochemical properties and the antibacterial activity of the SCG-enriched gums against oral pathogens were assessed. SCG extract showed a total phenolic content of 999.38 ± 2.63 μg/g and demonstrated antioxidant activity with a 50% inhibitory concentration (IC₅₀) of 107.28 ± 1.90 μL/mL. T25 showed the highest phenolic content (256.66 ± 2.93 μg/g) and enhanced scavenging activity IC₅₀ = 211.05 ± 0.65 (DPPH) and 128.52 ± 4.05 μL/mL (ABTS). T25 demonstrated superior antimicrobial effects against Streptococcus mutans and Enterococcus faecalis at 400 µL/mL, with inhibition zones of 33.33 ± 2.89 and 20.33 ± 0.58 mm compared to T0. Both T25 and T0 inhibited Lactobacillus acidophilus similarly. Overall, incorporating SCG extract into natural frankincense-based gum presents a promising biodegradable functional gum with potential oral health benefits. Full article

Objective: This study aimed to describe the main microorganisms causing catheter-related bloodstream infections (CRBSIs) and to evaluate the effectiveness of taurolidine catheter lock therapy in children with intestinal failure (IF) receiving parenteral nutrition (PN). Study design: This retrospective study included 31 pediatric patients with IF admitted between 2017 and 2022 who received PN via central venous catheters (CVCs). Demographic, clinical, and laboratory data were collected, along with information on PN use, catheter characteristics, and infection episodes, including clinical signs, microbiological cultures, and antimicrobial therapy. Serum C-reactive protein and albumin levels, as well as the use of taurolidine lock therapy, were analyzed. Results: The median age was 54.4 days among patients who developed CRBSI and 154.1 days among those without CRBSI. The median duration of PN was 119 days in patients with CRBSI and 89 days in those without. Nineteen patients experienced CRBSI, accounting for 55 infection episodes confirmed by blood cultures obtained from CVCs. The most frequently isolated microorganisms were Staphylococcus epidermidis, Enterococcus faecalis, and Klebsiella pneumoniae. Taurolidine lock therapy was significantly associated with lower infection rates per 1000 catheter days, with most infected catheters and infection episodes occurring in the absence of taurolidine use. Conclusions: These findings contribute to the characterization of the microbiological profile of CRBSIs in pediatric patients with IF and support the use of advanced preventive strategies, such as taurolidine lock therapy, to reduce infection rates in children receiving long-term PN. Full article

This study evaluated the alleviating effects of three heat-inactivated Enterococcus faecalis strains on growth suppression, oxidative stress, and gut microbiome dysbiosis in Macrobrachium rosenbergii-fed sesame meal-substituted fish meal diets. The trial comprised a control group (CT), low fish meal group (LF), and LF fed with three postbiotic-supplemented groups (LF+HK-448, LF+HK-798, LF+HK-804). Results demonstrated that compared with the CT group, the LF diet significantly decreased weight gain rate, specific growth rate, hepatopancreatic total nitric oxide synthase and inducible nitric oxide synthase, while increased feed conversion ratio, nitric oxide, and malondialdehyde contents. Among the postbiotics, LF+HK-804 group conferred the most pronounced compensatory growth and significantly improved oxidative stress and immune markers, as evidenced by elevated WGR, SGR, HSI, and flesh percentage, reduced MDA, and the down-regulation of Toll and Relish alongside the upregulation of peroxiredoxin-5. Intestinal microbiota analysis showed the group of LF+HK-804 improved microbial diversity and richness, specifically by increasing Firmicutes and decreasing Habeamium and Sphingomonas. Metabolomics identified 11 key differential metabolites related to amino acid, energy, and fatty acid metabolism. Correlation analysis further revealed that Gemmatimonadetes, WD2101_soil_group, and Sphingomonas were negatively correlated with phospholipids and positively correlated with glycoside and fatty acid metabolites. Moreover, immunometabolic correlation analysis segregated the metabolic response of microbiota into two distinct profiles: one potentiating a reactive oxygen/nitrogen species–antioxidant defense, and the other favoring a Dorsal/Relish-mediated transcriptional response. In conclusion, E. faecalis 804 can promote growth, alleviate oxidative damage, enhance immunity, and regulate intestinal microbiota and metabolic capacity in M. rosenbergii, showing great potential as a postbiotic. Full article

Background/Objectives: Oral infections are caused by a wide spectrum of bacterial and fungal species and remain clinically challenging, particularly against the background of increasing antimicrobial resistance and efforts to reduce antibiotic use in dentistry. Platelet concentrates are widely applied in periodontal and oral surgery due to their regenerative and immunomodulatory properties, and accumulating evidence suggests additional antimicrobial effects. This study evaluated the antimicrobial activity of platelet-rich plasma (PRP), platelet-rich fibrin (PRF), and injectable PRF (i-PRF) against clinically relevant oral microorganisms. Methods: PRP, PRF, and i-PRF were prepared from venous blood of five healthy donors and evaluated using diffusion-dependent, qualitative-semiquantitative agar diffusion assays against Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Staphylococcus aureus, Streptococcus mutans, Streptococcus mitis, Enterococcus faecalis, and Candida albicans, with inhibition zones assessed after species-specific incubation times. Chlorhexidine (2%) and amoxicillin served as positive controls and NaCl (0.9%) as negative control. Inhibition zones were digitally quantified and analyzed using non-parametric statistics (Kruskal–Wallis, Friedmann) due to skewed distributions and frequent zero values. Results: All platelet concentrates demonstrated microorganism-dependent inhibition zones in vitro. Overall, i-PRF demonstrated the strongest inhibitory effect across all pathogens (p < 0.001). Significant differences were detected for E. faecalis and C. albicans, where i-PRF produced markedly larger inhibition zones compared to PRP and PRF. Descriptively, anaerobic periodontal pathogens and S. aureus tended to be more susceptible, while streptococci and C. albicans demonstrated lower inhibition. Conclusions: These findings support a potential adjunctive antimicrobial role of platelet-derived preparations in dental infection management but should be interpreted with caution, as agar diffusion results do not necessarily reflect clinical performance. Full article

Background/Objectives: Chronic wounds represent a significant clinical burden and require multimodal treatment strategies targeting inflammation, infection, moisture balance, and tissue remodeling, as defined by the TIME framework. This study aimed to evaluate the therapeutic potential of innovative hydrogel dressings enriched with fungal biomass, designed to exploit natural bioactive compounds—such as antimicrobial peptides and proteolytic enzymes—to enhance wound healing while maintaining high biocompatibility. Methods: Hydrogel dressings incorporating selected fungal biomasses were fabricated and characterized for physicochemical and biological performance. Key material properties relevant to wound care, including hydrophilicity and porosity, were analyzed to assess exudate management capacity and maintenance of a moist wound environment. Antimicrobial activity was tested against common wound pathogens, and species–pathogen interactions were evaluated using generalized linear modeling. In vitro biocompatibility was assessed using human keratinocytes and compared with conventional silver nanoparticle–based dressings. Results: The developed hydrogels demonstrated properties suitable for clinical application, including superhydrophilicity and high porosity, supporting effective exudate control and moisture retention. Significant broad-spectrum antimicrobial activity was observed, particularly against Staphylococcus aureus and Pseudomonas aeruginosa, with effects dependent on fungal species. Statistical modeling revealed highly significant interactions between fungal species and pathogens in inhibition zones (p < 0.001). Hydrogels containing Pleurotus ostreatus and Agaricus bisporus showed broad activity against Escherichia coli, P. aeruginosa, and S. aureus, whereas Enterococcus faecalis exhibited resistance. Fungal biomass–based dressings displayed superior keratinocyte biocompatibility compared to silver nanoparticle controls. Conclusions: Fungal biomass–reinforced hydrogels offer a promising, safer, multifunctional alternative for infected chronic wound management, supporting both antimicrobial action and tissue regeneration. Full article

Background: Blue laser light has been the subject of research regarding the inactivation of microorganisms as a possible alternative to chemical treatment methods for a number of years. In dentistry, blue light could be used, for example, in the treatment of periodontitis/peri-implantitis, as well as in endodontics and against caries. It could serve as an alternative or supplement to traditional chemical and/or invasive methods. The antimicrobial effectiveness of a blue laser in relation to the speed of treatment is investigated using three different microbial test organisms in order to identify possible species differences. Methods: The test organisms Enterococcus faecalis, Streptococcus mutans, and Candida albicans were applied to smooth zirconium discs and treated twice with a diode laser at 445 nm wavelength with a traversing speed of 1, 2, and 4 mm/s. The antimicrobial effect was analysed based on the resulting colony-forming units on agar plates. The temperature was measured during the treatment. Preliminary tests were carried out using the MTT dye test to determine relevant setting parameters and the required energy dose. Results: Statistically significant differences were found between the negative control and the treated samples for all three tested organisms, with a maximum viability reduction of 1.8 log₁₀ CFU/mL for Enterococcus faecalis, 2.5 log₁₀ CFU/mL for Streptococcus mutans, and 1.0 log₁₀ CFU/mL for Candida albicans at 1 mm/s traversing speed, regarding estimated marginal means (p < 0.001). The temperature on the substrate surface reached 30 to 42 °C for all samples evaluated. Conclusions: Blue laser light (445 nm) demonstrates antimicrobial activity, which increases with prolonged exposure. Further research is needed to assess all key influencing parameters and define possible clinical applications. Full article

Heat-killed Enterococcus faecalis EF-2001 (EF-2001) is a postbiotic preparation reported to modulate host immunity. However, its specific impact on host immune responses and virological outcomes during the early phase of influenza infection remains insufficiently characterized. Female BALB/c mice received oral EF-2001 (16 mg/kg/day) for either 4 days or 14 days prior to intranasal inoculation with influenza A/H3N2 (A/Aichi/2/68). On day 2 post-infection, splenic T-cell subsets (CD3⁺, CD4⁺, CD8⁺) were quantified by flow cytometry. Cytokines released from PMA/ionomycin-stimulated splenocytes were measured using a cytometric bead array assay to assess functional polarization. Lung viral titers (TCID₅₀) and interferon-α (IFN-α) concentrations were assessed to evaluate local antiviral efficacy. EF-2001 administration significantly increased the proportions of splenic CD3⁺ T cells, including both CD4⁺ and CD8⁺ subsets, compared to controls. The 14-day pretreatment regimen significantly enhanced IFN-γ production while reducing IL-10, IL-4, and IL-2 secretion, consistent with a distinct systemic Th1-skewed immune activation. In contrast to these systemic effects, EF-2001 did not significantly reduce lung viral titers (difference < 0.2 log₁₀ TCID₅₀) and did not increase lung IFN-α concentrations at day 2 post-infection. Oral EF-2001 pretreatment promoted systemic immune activation characterized by T-cell expansion and a Th1-biased cytokine profile. However, this systemic priming showed no detectable antiviral effect on lung viral burden at the early evaluation time point. EF-2001 may be better positioned as an adjunctive immunomodulatory approach rather than a direct antiviral agent, warranting further studies that include clinical outcomes and multi-time-point antiviral and mucosal immune assessments. Full article

The rise of multidrug-resistant enteric pathogens and increased demand for antibiotic alternatives have intensified efforts to find reliable, safe, and effective probiotics. This study reports the isolation, characterization, and assessment of the probiotic potential of five Enterococcus strains isolated from the feces of healthy goats aged 7–9 months raised under conventional management. Following an initial screening of 57 lactic acid bacteria, 5 isolates (Enterococcus faecium, E. hirae, E. faecalis, Enterococcus sp., and Streptococcus lutetiensis) were chosen based on their catalase-negative, non-motile, and non-hemolytic characteristics, in addition to their high tolerance to gastric (pH 2.0) and intestinal (pH 8.0, 0.3–1.5% bile salt) stress. In simulated gastric juice, survival rates reached 89.05% (E5) and 85.03% (E3), while in intestinal juice, survival peaked at 78.01% (E4). All strains thrived in 4% NaCl and maintained at least 8 Log₁₀ CFU/mL after 12 h of exposure to 1.5% porcine bile salt. Cell surface hydrophobicity (0.78–93.85%) and auto-aggregation (23–91%) properties were strain-dependent, but exceeded the thresholds required for efficient gut colonization. Co-aggregation assays demonstrated over 45% binding with E. coli and S. typhimurium, suggesting a strong potential to displace pathogens. Cell-free supernatants created inhibition zones measuring 15.02 mm against E. coli and 11.04 mm against S. flexneri, while maintaining activity against methicillin-resistant S. aureus (MRSA). Antibiotic testing indicated that all strains were sensitive to ciprofloxacin and florfenicol. No β-hemolysis or mobile resistance genes were found, supporting the initial safety findings. This study reveals that Enterococcus isolates from goats display a unique combination of gastrointestinal survivability and broad-spectrum antipathogenic activity and, therefore, are promising candidates for the development of next-generation probiotic strains for use in livestock (and, potentially, humans). Further in vivo validation and genome-based safety assessments are warranted. Full article

Antimicrobial resistance is a growing global health threat, necessitating alternatives to conventional antibiotics. Bacteriophages, viruses that specifically target bacteria, represent a promising option, and phage-loaded electrospun fibers have recently gained attention as wound dressings for localized phage therapy. However, the influence of phage morphology and scaffold design has been largely overlooked. This study investigates how phage morphology and structure, in conjunction with scaffold design and processing conditions, may influence the biological performance of electrospun scaffolds. A bilayer scaffold was developed comprising a supportive polycaprolactone (PCL)/gelatin (70:30) layer and a polyvinyl alcohol (PVA) top layer loaded with bacteriophages. Two phage types, short-tailed podovirus APTC-SL.1 and long-tailed myovirus APTC-Efa.20, were incorporated into PVA fibers to evaluate their antibacterial activity against Staphylococcus lugdunensis and Enterococcus faecalis, respectively. The fibers were characterized using XRD, FTIR, TGA, optical microscopy, SEM, TEM, wettability analysis, and in vitro degradation tests. Biological assessments included antimicrobial testing, phage viability, and phage release. The bilayer scaffold containing short-tailed phages preserved phage viability and produced clear zones of lysis against S. lugdunensis, with ≈8.15% viability retained after electrospinning and relatively controlled release, whereas long-tailed phages showed no antibacterial activity. These results suggest that phage structure and morphology, together with electrospinning conditions and scaffold architecture, may play an important role in maintaining phage functionality in wound dressing applications, while acknowledging that host–phage interactions may also contribute to the observed differences. Full article

The interaction between the gut microbiota and human health has gained increasing recognition, accelerating advances in microbiome research. While early studies have emphasized probiotics, concerns regarding antibiotic resistance and adverse effects, such as sepsis, have shifted research interest towards heat-treated microbial cells or postbiotics. This study investigated the therapeutic potential of heat-killed postbiotic Enterococcus faecalis EF-2001—one of the most widely used postbiotics worldwide—for the prevention and treatment of muscle atrophy. In vitro, mouse C2C12 myotubes were pretreated with heat-killed postbiotic EF-2001 (50–500 μg/mL) for 48 h and then treated with dexamethasone (100 μM) to induce muscle atrophy. In vivo, male Sprague Dawley rats were treated with low-dose (3 mg/kg) and high-dose (30 mg/kg) EF-2001 for efficacy studies. Heat-killed postbiotic EF-2001 attenuated cellular and DNA damage in dexamethasone-induced C2C12 myotubes. Specifically, heat-killed postbiotic EF-2001 increased AKT phosphorylation while suppressing Atrogin-1 expression, thereby alleviating muscle atrophy. In a Sprague Dawley rat model, heat-killed postbiotic EF-2001 significantly reduced dexamethasone-induced muscle loss by regulating muscle atrophy-associated signaling pathways, including Atrogin-1 expression. Collectively, these findings demonstrate that heat-killed EF-2001 alleviates dexamethasone-induced muscle atrophy and support its potential as a postbiotic. This study provides a solid foundation for future human clinical studies by establishing preclinical evidence for the biological activity of heat-killed EF-2001. Full article