Search Results (658)

Modern agriculture faces the critical need to develop sustainable, safe, and effective strategies for enhancing productivity, protecting plants and animals, and ensuring food security. Challenges posed by antibiotic resistance and the adverse environmental and consumer health impacts of chemical agents are driving the search for eco-friendly alternatives. In this context, bacteriocins—naturally occurring antimicrobial peptides synthesized by diverse bacteria—represent a promising alternative to traditional chemical compounds. This article reviews the potential and current advances in bacteriocin applications across agricultural sectors, with particular focus on their targeted antagonistic activity, structural diversity, commercial bacteriocin-based products, and their utilization in livestock farming, crop production, poultry farming, and aquaculture. Key findings demonstrate that bacteriocins, particularly nisin and pediocin PA-1, exhibit potent activity against major agricultural pathogens including Listeria monocytogenes, Staphylococcus aureus, Clostridium perfringens, and Escherichia coli, with efficacy rates reaching 90% in mastitis treatment and significantly reducing pathogen loads in poultry and aquaculture systems. Commercial products such as Nisaplin, Wipe Out, and ALTA 2431 have been successfully implemented in veterinary medicine and food production. In aquaculture, bacteriocins effectively control Lactococcus garvieae, Aeromonas spp., Vibrio spp., and Pseudomonas aeruginosa, contributing to sustainable disease management with minimal environmental impact. It can be suggested that bacteriocins may play an essential role in combating pathogens and offer viable alternatives to conventional antibiotics across primary food production systems, though optimization of production methods and regulatory frameworks remains essential for broader commercial adoption. Full article

Meat rabbits are ideal meat-producing animals. However, weaning-induced intestinal inflammation often leads to growth delays, and severe cases impair breeding efficiency. Alfalfa polysaccharides (APSs) have antioxidant and anti-inflammatory properties, making them potential natural alternatives to antibiotics. To date, relatively limited research has been conducted on APS in meat rabbits. This research investigated the effects of APS on growth performance, intestinal inflammation, and meat quality in rabbits. Eighty healthy rabbits were randomized into four treatment groups, each group consisting of five replicates, with four rabbits per replicate. The four experimental groups were the control group (CON, basal diet), 400 mg/kg APS group (basal diet + 400 mg/kg APS), 800 mg/kg APS group (basal diet + 800 mg/kg APS), and 1200 mg/kg APS group (basal diet + 1200 mg/kg APS). The results indicated that adding 800 mg/kg APS to the diet significantly increased ADG (p < 0.001) and reduced F/G (p = 0.008). With increasing APS supplementation levels, slaughter weight (p = 0.035), eviscerated weight (p = 0.020), semi-eviscerated weight (p = 0.015), and semi-eviscerated yield percentage (p = 0.035) were all significantly increased. Additionally, dripping loss in muscle was significantly reduced in the 800 mg/kg APS group (p = 0.006). In addition, the villus height of the small intestine and the expression of tight junctions were significantly increased by 800 mg/kg APS supplementation, which reduced intestinal permeability and lowered levels of intestinal inflammatory mediators by inhibiting the PPARγ/NF-κB pathway. Additionally, a diet with APS significantly increased the abundance of Flavonifractor, a butyrate-producing bacterium in the cecum. Cell assays further demonstrated that butyrate could inhibit the release of inflammatory cytokines from RAW264.7 via the PPARγ/NF-κB pathway. In conclusion, APS improved growth performance by reshaping the gut microbiota and increasing the level of butyrate in the cecum, further inhibiting intestinal inflammation through the PPARγ/NF-κB signaling pathway. Full article

The misuse of antibacterial agents has contributed to the growing prevalence of antibiotic resistance, highlighting an urgent need to explore alternative anti-infection therapeutic strategies. Antimicrobial peptides (AMPs) are naturally occurring molecules. They exhibit broad-spectrum antimicrobial activity and represent promising candidates for the development of novel therapeutics. A cysteine-rich antimicrobial peptide was identified and characterized from the genome of Tigriopus japonicus and designated “TjRcys1”. The precursor form of TjRcys1 comprises 96 amino acids. Structural analyses of TjRcys1 revealed random coils, two α-helices, and two β-strands. Recombinant TjRcys1 had inhibitory effects upon Staphylococcus aureus and Bacillus sp. T2, with a minimum inhibitory concentration of 64 μM for both. TjRcys1 did not show complete inhibition against Vibrio alginolyticus, Klebsiella pneumoniae, or Aeromonas hydrophila at 64 μM, but it did slow their growth rate. TjRcys1 could disrupt the permeability of the cell membrane of S. aureus. Transcriptomic analyses indicated that TjRcys1 could interfere with the ribosome biosynthesis and nucleotide metabolism of K. pneumoniae. Our results provide a valuable reference for the development of new AMPs and optimization of their design. Full article

The intensification of aquaculture practices has been accompanied by an increased incidence of bacterial diseases, leading to a greater reliance on antibiotics for disease control. Consequently, the widespread and often indiscriminate use of these compounds has contributed to the emergence and dissemination of antibiotic-resistant bacteria within aquaculture systems, posing a serious threat to animal health, environmental sustainability, and public health. In this regard, research efforts have focused on developing alternative strategies to reduce antibiotic use. Natural compounds have gained particular attention due to their well-documented antimicrobial and antibiofilm activities. In this context, the combined application of antibiotics and natural compounds has emerged as a promising approach to enhance antimicrobial efficacy while potentially mitigating the development of resistance. This review synthesizes the current knowledge on antibiotic resistance in aquaculture, highlights the role of biofilm formation as a key resistance mechanism, and critically examines the potential of antibiotic–natural compound combinations against major aquaculture pathogens, with particular emphasis on bacterial growth inhibition, biofilm disruption, and virulence attenuation. Collectively, the evidence discussed underscores the potential of synergistic strategies as a sustainable tool for improving disease management in aquaculture while supporting efforts to limit antibiotic resistance. Full article

The increasing prevalence of multidrug-resistant (MDR) Campylobacter species poses a serious threat to food safety and public health, highlighting the urgent need for natural antimicrobial alternatives to conventional antibiotics. This study investigated the antibacterial potential and mechanism of action of seven essential oils (EOs), Cymbopogon citratus, Mentha pulegium, Artemisia absinthium, Myrtus communis, Thymus algeriensis, Thymus capitatus, and Eucalyptus globulus, against multidrug-resistant Campylobacter jejuni and Campylobacter coli. The antimicrobial activity was first assessed by the agar disk diffusion and broth microdilution methods to determine inhibition zones, minimum inhibitory concentrations (MICs), and minimum bactericidal concentrations (MBCs). The most active EOs were further evaluated through time–kill kinetics, cell lysis, salt tolerance, and membrane integrity assays to elucidate their bactericidal mechanisms. Results showed that E. globulus, T. algeriensis, and M. communis exhibited the strongest inhibitory effects, particularly against C. jejuni, with MIC values ranging from 3.125% to 6.25%, while C. coli was more resistant. Time–kill and lysis experiments demonstrated rapid bacterial reduction and significant decreases in optical density, indicating cell disruption. Additionally, EO treatments reduced salt tolerance and induced leakage of cytoplasmic materials, confirming membrane damage. Overall, these findings suggest that selected essential oils exert potent antimicrobial effects through membrane disruption and osmotic imbalance, offering promising natural strategies to control MDR Campylobacter in food systems. The application of such bioactive compounds could contribute significantly to improving food quality, extending shelf life, and enhancing food safety. Full article

Methicillin-resistant Staphylococcus aureus (MRSA), a major global public health threat due to its broad resistance, urgently requires the development of new antibiotic alternatives. (‒)‒Epigallocatechin-3-gallate (EGCG) is considered a natural bioactive compound with anti-MRSA properties. The L-Lectin module of serine-rich adhesin for platelets (SraP) is considered an important target for blocking MRSA-infected hosts. This study aims to investigate the mechanism of action of EGCG against MRSA. Surface plasmon resonance (SPR), cell adhesion and invasion, biofilm formation, checkerboard assays, RNA sequencing (RNA-seq) and quantitative real-time polymerase chain reaction (qRT-PCR) were performed. The results showed that EGCG bound to SraP L Lectin with high affinity and effectively inhibited MRSA colonization. Additionally, EGCG significantly suppressed pyrimidine metabolism and downregulated related genes, thereby potentially inhibiting bacterial growth. It also markedly reduced the expression of multiple genes associated with β-lactam resistance and inhibited biofilm formation. A strong synergistic effect was observed between EGCG and the bactericidal agent ceftriaxone (CRO). When combined with 10 μg/mL EGCG, CRO required 75% less dosage and exhibited a prolonged antimicrobial effect. In conclusion, EGCG exerts anti-MRSA effects through multiple pathways and represents a promising candidate as an alternative therapeutic agent against MRSA infections. Full article

The increasing problem of antibiotic resistance is a critical global health issue, necessitating the development of alternative therapeutic strategies to manage infections effectively. Among the promising solutions are human antimicrobial peptides (AMPs), naturally occurring molecules known for their broad spectrum of antimicrobial activity. Background/Objectives: This study investigates the potential of some AMPs, selected through a bioinformatic approach, as alternatives to conventional antibiotics, particularly focusing on their efficacy against species within the Bacteroidota phylum. These species, including pathogens such as Porphyromonas gingivalis, Capnocytophaga ochracea, and Capnocytophaga canimorsus, are well known for their roles in various human infections and related diseases. Non-pathogenic environmental species, such as Flavobacterium johnsoniae, are also included in this group, frequently used as a model organism. Methods: By analyzing the antimicrobial efficacy, mechanisms of action, and potential therapeutic applications of human AMPs, this research underscores their significance in addressing the challenge of antibiotic resistance. Results: This study identified three peptides, KTL24, LIR23, and MFP22, as particularly interesting. These peptides are derived from specific human proteins, namely SPI1, NAPSA and SCUB1. Conclusions: Their notable antimicrobial potential suggests that AMPs could serve either as a complementary treatment alongside traditional antibiotics or as a standalone therapy, mitigating the ongoing spread of antibiotic resistance and offering an alternative in global health strategies. Full article

Background/Objectives: Emerging biofilms of uropathogenic bacteria, particularly P. aeruginosa, on medical devices such as urinary catheters, lead to complications in the treatment of urinary tract infections (UTI). Considering the spread of antibiotic resistance, the search for alternative efficient control options for biofilms is of great medical interest. Methods: Curcumin, 1-monolaurin, n-undecyl-α/β-l-fucopyranoside, and the fungal metabolite terrein were investigated for their influence on biofilm formation by P. aeruginosa on latex catheter pieces in artificial urine (AU), monitoring the number of colony-forming units per cm Latex-Catheter (CFU/cm Latex-Catheter). Results: Significant inhibition of P. aeruginosa biofilm formation [55.6% CFU reduction/cm²] was observed with the fungal metabolite terrein at 256 µg/mL AU. At a concentration of 512 µg/mL AU, terrein achieved almost complete inhibition of biofilm formation. n-undecyl-α/β-l-fucopyranoside inhibited biofilm formation [58.3% CFU reduction/cm²] by P. aeruginosa ATCC 27853 at 512 µg/mL AU. Compared to that, it caused an increase in biofilm formation [87.0% CFU increase/cm²] by P. aeruginosa PA 01 at 256 µg/mL AU. This study is limited by the fact that no investigations into the possible cytotoxicity of the two active substances, terrein and n-undecyl-α/β-l-fucopyranoside, on healthy eukaryotic cells have been carried out. Conclusions: Natural substances may be a promising approach to prevent the formation of P. aeruginosa biofilms. For antibacterial applications, fungal metabolites, such as terrein, offer a novel approach to prevent biofilms in urological practice. Full article

The widespread use of antibiotics in human medicine, veterinary care, and livestock production has resulted in their frequent detection in diverse environmental and food matrices, making continuous surveillance of antibiotic residues in food products essential for consumer protection. In this study, a sustainable analytical method based on dispersive liquid–liquid microextraction (DLLME) coupled with UHPLC–MS/MS was developed for the trace determination of sulfamethoxazole, sulfadimethoxine, and enrofloxacin in commercial cow milk and chicken eggs. A natural deep eutectic solvent (NADES) composed of anisaldehyde and octanoic acid (2:1, molar ratio) was employed as a biodegradable extraction solvent, and key extraction parameters were systematically optimized. Under optimized conditions, the method demonstrated excellent linearity (R² ≥ 0.9982), recoveries of 89.5–98.7%, and RSDs ≤ 6.04%. Application to 44 commercial samples from the Saudi market revealed sulfamethoxazole as the most frequently detected antibiotic, occurring in 90% of egg samples (2.17–13.76 µg kg⁻¹) and 70.8% of milk samples (0.26–26.67 µg L⁻¹). A comprehensive evaluation using ten metrics confirmed the method’s greenness, practicality, analytical performance, and innovation. Overall, the proposed NADES–DLLME–UHPLC–MS/MS approach offers a rapid, cost-effective, and environmentally friendly alternative for routine monitoring of antibiotic residues in food matrices. Full article

Background/Objectives: Antimicrobial peptides (AMPs), evolutionarily conserved components of innate immunity characterized by their broad-spectrum efficacy and minimal resistance development, are increasingly recognized as promising therapeutic candidates. This review aims to integrate current knowledge concerning natural and synthetic antimicrobial peptides and their therapeutic effectiveness in addressing gastrointestinal infections. Methods: A literature review was performed, evaluating recent peer-reviewed studies on AMPs. The research concentrated on their molecular mechanisms of action, antimicrobial spectrum, and their interactions with standard antibiotics. More in detail, the peptide classes examined herein included defensins, cathelicidins, histatins, and various natural peptides such as lactoferricin, protamines, RegIII, and hepcidin, along with synthetic analogs like WR12, D-IK8, MSI-78, and IMX942. Results: Natural AMPs demonstrated significant antimicrobial and immunomodulatory effects against Escherichia coli, Klebsiella pneumoniae, Salmonella spp., and Shigella spp. Beyond direct antimicrobial activity, antimicrobial peptides act as integrated anti-infective agents not only by modulating host–microbiota interactions, but also preserving epithelial barrier integrity, and limiting inflammation, thereby offering a multifaceted strategy to control gastrointestinal infections. On the other hand, synthetic peptides showed improved stability, reduced cytotoxicity, and synergistic interactions with antibiotics, which suggests that they could be used either alone or in combination with other treatments. Conclusions: AMPs constitute a promising category endowed with anti-infective activity, especially for therapy of intestinal diseases, which is attributed to their distinctive anti-infective mechanisms, immune-modulating characteristics, and a relatively low propensity for resistance development compared to conventional antibiotics. However, more clinical trials and improvements to their formulation are needed to translate promising in vitro results into reliable patient outcomes. Full article

The search for natural alternatives to in-feed antibiotics is a central focus in sustainable poultry production. This study investigated the individual and combined effects of Sanguinarine (SA) and Achyranthes bidentata polysaccharides (ABPS), two bioactive compounds derived from Chinese herbs, on the growth performance and immune function of yellow-feathered broilers. A total of 1728 one-day-old female broilers were randomly allocated to 36 treatment groups in a 6 × 6 factorial arrangement, with factors being six levels of SA (0, 0.4, 0.5, 0.6, 0.7, and 0.75 mg/kg) and six levels of ABPS (0, 200, 300, 400, 500, and 600 mg/kg). Over an 8-week period, growth performance indicators, including average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR), were monitored. Immune status was assessed through relative weights of immune organs (thymus, bursa of Fabricius, spleen) and lymphocyte proliferation at 4 and 8 weeks of age. The results demonstrated that SA supplementation significantly improved ADG during the initial 0–2-week period, while its effects on ADFI and FCR varied across different growth stages. ABPS supplementation was most effective in reducing FCR throughout the experiment, with the optimal effect observed at 500 mg/kg. Regarding immune parameters, SA at 0.7 mg/kg yielded the highest relative immune organ weights and lymphocyte proliferation at 4 weeks, whereas 0.5 mg/kg was most effective for lymphocyte proliferation at 8 weeks. ABPS at 500 mg/kg consistently promoted immune organ development and lymphocyte proliferation. A significant synergistic interaction between SA and ABPS was identified for several key outcomes. This interaction influenced ADG and ADFI at 8 weeks of age, relative thymus weight at 4 weeks, and lymphocyte proliferation at both 4 and 8 weeks. Notably, the combination of SA at 0.5 mg/kg and ABPS at 300 mg/kg (A₃B₃) produced a marked enhancement in lymphocyte proliferation. In conclusion, dietary supplementation with SA, ABPS, or their combination can modulate growth performance and enhance immune function in yellow-feathered broilers. The effects are dose-dependent and can be synergistic, with the combination of 0.5 mg/kg SA and 300 mg/kg ABPS showing particular promise for boosting cell-mediated immunity. These findings support the potential of SA and ABPS as beneficial natural feed additives for antibiotic-free poultry production. Full article

Background/Objectives: Staphylococcus (S.) aureus is a major pathogen causing bovine mastitis and is often refractory to antibiotic therapies due to virulence factors and resistance mechanisms. In this pilot study, the safety and efficacy of an intramammary phage cocktail, in naturally S. aureus-infected dairy cows, were investigated. Methods: The initial part of the study on farm 1 confirmed tolerability and safety, as there were no observed systemic side effects of treatment. The subsequent efficacy study on farm 2 included 23 with S. aureus infected udder quarters, which were randomly divided into a treatment group (n = 16) and a control group (n = 7). The quarters in the treatment group received five intramammary infusions of the phage cocktail at 12-h intervals. Results: This resulted in a bacteriological cure rate of 81.3% (13/16) for the treatment group, compared to 28.6% (2/7) in the control group (p = 0.026). Conclusions: These results indicate that phage therapy is well-tolerated and may be a promising alternative to antibiotics for treating S. aureus mastitis, although confirmation in larger-scale, multicenter studies is required. Full article

Group B Streptococcus (GBS) is a component of the natural human microbiota, colonizing the genitourinary tract and the distal gastrointestinal tract. Due to its production of numerous virulence factors, GBS can cause infections in pregnant women, newborns, and immunocompromised individuals. In newborns, GBS infection may present as severe pneumonia, meningitis, or sepsis. Screening for maternal GBS colonization, combined with intrapartum antibiotic prophylaxis for colonized women, is currently regarded as the most effective strategy for preventing neonatal GBS infections. However, growing concerns regarding antibiotic resistance and the negative impact of antibiotics on the neonatal microbiome have intensified the search for alternative approaches. These include the development of a vaccine and methods to reduce vaginal colonization in pregnant women. Full article

Background: Methicillin-resistant Staphylococcus aureus (MRSA) remains a major global health concern owing to its multidrug resistance and persistence despite continued antibiotic development. Eco-friendly nanomaterials such as selenium nanoparticles (SeNPs) have emerged as promising antimicrobial alternatives because of their high biocompatibility and lower toxicity compared to conventional metallic nanoparticles. In this study, we investigated the inhibitory effects and underlying mechanisms of Lactiplantibacillus plantarum (LP)–derived SeNPs (LP-SeNPs) on MRSA. Methods: SeNPs were biosynthesized using the antibacterial cell-free supernatant (CFS) of LP, which provides naturally reducing and stabilizing biomolecules. The resulting LP-SeNPs were characterized by physicochemical and structural analyses and compared to chemically synthesized SeNPs (Chem-SeNPs). Antibacterial activity was assessed through minimum inhibitory concentration (MIC) testing, time-kill kinetics, and cell viability assays. Results: LP-SeNPs, which were spherical with an average diameter of 107 nm, exhibited selective antibacterial activity against Gram-positive bacteria and showed no effect on Gram-negative strains. Notably, all six MRSA isolates demonstrated high susceptibility, with MIC values approximately 100-fold lower than that of S. aureus ATCC 25923, a non-MRSA reference strain. LP-SeNPs were also non-cytotoxic up to 20-fold the MIC (IC₅₀ > 10 µg/mL). Mechanistic analyses indicated that disruption of the bacterial cell membrane was the primary antibacterial mechanism, supported by additional contributions from reactive oxygen species generation and protein synthesis inhibition. Conclusions: LP-SeNPs represent a sustainable, biocompatible, and potent antibacterial nanoplatform with strong selectivity for Gram-positive pathogens, particularly MRSA. These findings highlight their potential as eco-friendly and targeted therapeutic strategies for combating MRSA infections. Full article

The extensive use of antibiotics in intensive farming weakens immunity and threatens food safety. Stevia isochlorogenic acid (SICA), a kind of dicaffeoylquinic acid derived from stevia residue, exhibits strong antioxidant activity. This study evaluated the ability of SICA to improve immune function in an immunosuppressed broiler model. SICA significantly increased the spleen, thymus, and bursa of Fabricius indices (p < 0.05), alleviated spleen damage, and elevated serum interleukin-2 (IL-2), IL-4, interferon-γ, IL-1β, tumor necrosis factor-α, immunoglobulins (IgA, IgM, IgG), and complement components C3 and C4 (p < 0.05). Isobaric tags for relative and absolute quantification-based proteomics indicated that SICA enhanced splenic immune function by activating cell adhesion molecules, phagosomes, and the intestinal immune network for IgA production pathways. Quantitative PCR analysis showed upregulation of mRNA and protein levels of B-cell receptor, major histocompatibility complex class II, protein tyrosine phosphatase receptor type C, and neutrophil cytosolic factor 2 (p67phox) and downregulation of C-C motif chemokine receptor 9. Molecular docking demonstrated the strongest binding affinity between SICA and p67phox. Overall, SICA effectively alleviated immunosuppression in broiler chickens and represents a promising natural alternative to antibiotic feed additives. Full article