Search Results (647)

Tocosh, a traditional Peruvian fermented potato product, is known for its health-promoting properties, including its antioxidant, anti-inflammatory, probiotic, and antibiotic effects, which have popularized its consumption, particularly in rural areas. To gain a better understanding of its antimicrobial properties, this study aimed to perform a comprehensive whole-genome analysis and functional assessment of the Bacillus velezensis TCSH0001 strain isolated from tocosh. The isolate was identified through whole-genome sequencing using the MinION nanopore platform. AntiSMASH analysis revealed nine biosynthetic gene clusters (BGCs) potentially responsible for producing secondary metabolites with antibiotic potential. Notably, seven BGCs showed a 100% similarity to known clusters involved in the biosynthesis of polyketide synthases (PKSs) and non-ribosomal peptides (NRPSs), including difficidin, bacillibactin, bacilysin, macrolactin H, bacillaene, fengycin, and bacillomycin D. In vitro analysis revealed antimicrobial activity against S. aureus strains. In addition, RT-qPCR indicated that the expression of the baeJ (bacillaene), bmyA (bacillomycin D), and pks2A (macrolactin H) occurs predominantly during the exponential growth phase. Our results suggest that this B. velezensis strain has the capacity to produce a diverse array of bioactive compounds, supporting the traditional use of tocosh as a natural antimicrobial agent, and revealing the potential of the strain as a high NRPS producer. Full article

Background/Objectives: Bacterial biofilms formed by Escherichia coli pose a significant challenge in veterinary medicine due to their intrinsic resistance to antibiotics. Antimicrobial peptides (AMPs) represent a promising alternative. AMPs exert their bactericidal activity by binding to negatively charged phospholipids in bacterial membranes via electrostatic interactions, leading to membrane disruption and rapid cell lysis. Methods: In vitro assays including MIC determination, biofilm eradication testing (crystal violet, colony counts, and CLSM), swimming motility, and EPS quantification were performed. CRISPR/Cas9 was used to construct and complement a kduD mutant. A transposon mutagenesis library was screened for biofilm-defective mutants. In an in vivo murine excisional wound infection model treated with the mouse cathelicidin-related antimicrobial peptide (CRAMP-34), wound closure and bacterial burden were monitored. Gene expression changes were analyzed via RT-qPCR. Results: CRAMP-34 effectively eradicated pre-formed biofilms of a clinically relevant, porcine-origin E. coli strain and promoted wound healing in the murine infection model. We conducted a genome-wide transposon mutagenesis screen, which identified kduD as a critical gene for robust biofilm formation. Functional characterization revealed that kduD deletion drastically impairs flagellar motility and alters exopolysaccharide production, leading to defective biofilm architecture without affecting growth. Notably, the anti-biofilm activity of CRAMP-34 phenocopied aspects of the kduD deletion, including motility inhibition and transcriptional repression of a common set of biofilm-related genes. Conclusions: This research highlights CRAMP-34 as a potent anti-biofilm agent and unveils kduD as a previously unrecognized regulator of E. coli biofilm development, which is also targeted by CRAMP-34. Full article

The emergence and dissemination of antimicrobial resistance (AMR) are driven by complex, interconnected mechanisms involving microbial communities, environmental factors, and human activities, with climate change playing a pivotal and accelerating role. Rising temperatures, altered precipitation patterns, and other environmental disruptions caused by climate change create favorable conditions for bacterial growth and enhance the horizontal gene transfer (HGT) of antibiotic resistance genes (ARGs). Thermal stress and environmental pressures induce genetic mutations that promote resistance, while ecosystem disturbances facilitate the stabilization and spread of resistant pathogens. Moreover, climate change exacerbates public and animal health risks by expanding the range of infectious disease vectors and driving population displacement due to extreme weather events, further amplifying the transmission and evolution of resistant microbes. Livestock agriculture represents a critical nexus where excessive antibiotic use, environmental stressors, and climate-related challenges converge, fueling AMR escalation with profound public health and economic consequences. Environmental reservoirs, including soil and water sources, accumulate ARGs from agricultural runoff, wastewater, and pollution, enabling resistance spread. This review aims to demonstrate how the Mediterranean’s strategic position makes it an ideal living laboratory for the development of integrated “One Health” frameworks that address the mechanistic links between climate change and AMR. By highlighting these interconnections, the review underscores the need for a unified approach that incorporates sustainable agricultural practices, climate mitigation and adaptation within healthcare systems, and enhanced surveillance of zoonotic and resistant pathogens—ultimately offering a roadmap for tackling this multifaceted global health crisis. Full article

Aquaculture has been established as a sustainable alternative to traditional fisheries, which face challenges such as overexploitation and environmental degradation. However, disease outbreaks, often caused by poor farming conditions, pollution, and environmental stress, remain a major concern, leading to economic losses and increasing the risk of antibiotic resistance due to the overuse of antibiotics. Therefore, it is crucial to seek new strategies that improve fish health and well-being, preventing drug resistance and promoting sustainable practices. GHRP-6, a synthetic growth hormone-releasing peptide that mimics ghrelin, has shown potential immunostimulatory properties and feed efficiency in fish. In this study, we evaluated the effects of orally administered GHRP-6 in an oil-based formulation on juvenile tilapia (Oreochromis sp.) challenged or unchallenged with Pseudomonas aeruginosa. We assessed its influence on immune gene expression and digestive enzyme activity. The results demonstrated that GHRP-6 treatment significantly enhanced growth performance (weight and length), reduced in vivo bacterial load after infection, and modulated key genes related to innate and adaptive immunity in the gills, intestine and head kidney. In addition, our results demonstrated, for the first time, a direct link between a growth hormone secretagogue in fish and the modulation of specific enzyme activity in the gut following a bacterial challenge. These findings highlight the potential of GHRP-6 as a dietary immunomodulator and growth promoter in fish farming, offering a promising strategy to reduce antibiotic usage and promote more sustainable aquaculture practices. Full article

Functional feed additives offer a viable strategy for producing sustainable and healthful poultry. Guanidinoacetic acid (GAA), a non-antibiotic growth stimulant, has attracted significant interest from both investors in the poultry sector and researchers due to its distinct biological properties and multiple potential applications. GAA facilitates creatine synthesis, accelerates metabolism, and boosts poultry growth. Consequently, GAA can be considered a safe and beneficial creatine substitute, as it is the sole natural precursor of creatine. GAA meets the livestock industry’s demand for safe and effective therapies because it is non-toxic, readily degradable, and leaves no residues. Additionally, GAA is more stable and economical than creatine, making it a superior feed additive. In broiler chicks, GAA can replace arginine in practical diets containing either adequate or deficient levels of arginine. Supplementation with GAA offers promising opportunities to optimize broiler production and general health by promoting energy metabolism and protein synthesis. Commercially available feed-grade GAA has a high potential for inclusion in broiler diets. Supplementing broiler chickens with GAA may be an effective approach to improve performance parameters such as body weight and feed conversion ratio. In conclusion, dietary GAA supplementation (approximately 0.6–1.2 g/kg of diet, depending on desired impacts) can improve the productive performance of poultry. This review updates current knowledge on the impacts of GAA on productive and reproductive performance, egg quality, digestibility, antioxidant indices, and gut health in poultry. 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

Magnetic biochars (MBCs) have been shown to inhibit the horizontal transfer of antibiotic resistance genes (ARGs) in soils, both with and without microplastics (MPs); however, the underlying molecular biological mechanisms remain unclear. This study examined the effects of MBCs and coexisting polybutylene adipate terephthalate microplastics (PBAT MPs) on the physiological characteristics of Serratia marcescens ZY01 (a host strain carrying the tet gene) and further investigated their relationships with the absolute abundance of the tet gene in soil. The results demonstrated that MBCs promoted prodigiosin synthesis in Serratia marcescens ZY01 by mediating the electron transfer process, the effect of which was further enhanced in the presence of PBAT MPs. In treatments without PBAT MPs, MBCs generally suppressed the production of both proteins and polysaccharides in the extracellular polymeric substances. In contrast, in treatments containing PBAT MPs, the protein content gradually decreased with decreasing iron-to-biochar ratios, while the polysaccharide content remained largely unchanged. MBCs also elevated intracellular ROS levels due to the increased oxidative stress, particularly in treatments with PBAT MPs. A positive correlation between intracellular ROS levels and cell membrane permeability indicates that intracellular ROS was the primary driver of the increased cell membrane permeability. The presence of MBCs and PBAT MPs generally provided favorable habitats for Serratia marcescens ZY01, thereby enhancing its cell viability. Mantel test analysis indicated that MBCs influenced Serratia growth in soil by modulating its cell viability. Furthermore, the increased intracellular ROS level was significantly positively correlated with the absolute abundance of the tet gene in soil, implying the horizontal transfer of the tet gene at the intra-genus level. These findings offer helpful insights for developing environmental remediation strategies based on biochar–iron composites. Full article

The limited cultivability of Actinomycetota strains restricts the exploration of their novel antibiotics, highlighting the need for improved isolation techniques. This study employed a helper strain-assisted cultivation method which utilizes culture supernatants from helper strains to isolate diverse members of the Actinomycetota from millipedes and compared its efficacy with a standard method. Using a preliminary dual-layer solid media assay and subsequent confirmation experiments, eight helper strains (M3, M9, M13, N3, N4, N6, N8, and N9) were identified, whose supernatants promoted the growth of Actinomycetota and other microbes. Application of this method to millipede samples established a novel cultivation strategy based on co-cultivation with helper strains. The new method enabled the isolation of 233 bacterial species in total, of which 143 were species of the phylum Actinomycetota, including 49 novel species. In contrast, the standard method yielded only 42 total bacterial species and 29 species of Actinomycetota, with merely 8 novel species. Comparative diversity analysis revealed that the helper strain-assisted method yielded Actinomycetota strains from 85 genera, which was 3.5 times higher than the standard method. This demonstrates that the helper strain-assisted approach is a highly effective strategy for accessing diverse and novel microbial majority. Among the isolated Actinomycetota strains, 75 strains predicted to have high biosynthetic gene clusters (BGCs) numbers or expected to be novel species were screened for antibacterial activity. Fourteen strains (17%) exhibited inhibitory effects against at least one indicator bacterium. One novel strain, Streptomyces sp. N8-31, was selected for whole-genome sequencing. AntiSMASH analysis predicted 40 biosynthetic gene clusters in N8-31, with 60% showing less than 70% similarity to known clusters; among these, 20 clusters showed less than 50% similarity. These findings indicate that strain N8-31 is a rich reservoir of novel genetic resources, and its broad-spectrum antibacterial activity is likely linked to these unique secondary metabolite gene clusters. Critically, this study confirms that helper strain-assisted cultivation is a powerful tool for unlocking the hidden biosynthetic potential of previously inaccessible Actinomycetota. Full article

Background: The global livestock industry faces pressure to reduce antimicrobial usage while maintaining animal health and productivity. Non-pharmaceutical interventions (NPIs) including probiotics, prebiotics, phytogenics, essential oils, organic acids, and enzymes have emerged as alternatives to antibiotic growth promoters. Commercial success depends on consumer acceptance and willingness to pay (WTP) for products from animals raised using these approaches. Objective: This systematic review synthesized peer-reviewed literature examining consumer knowledge, attitudes, perceptions, and WTP toward animal products produced using NPIs or marketed as antibiotic-free (ABF) to identify a critical gap in existing research. Methods: Following PRISMA 2020 guidelines, four databases (PubMed, Web of Science, Scopus, and Google Scholar) were searched for peer-reviewed studies published from January 2020 to December 2024. Inclusion criteria encompassed original research examining consumer perspectives toward NPIs or antibiotic-free (ABF) animal products. Narrative synthesis was employed due to study heterogeneity. Results: From 847 records, 15 studies met inclusion criteria. A critical finding was that virtually no peer-reviewed research directly examines consumer perceptions of specific NPIs such as probiotics, prebiotics, phytogenics, organic acids, or enzymes as feed additives. The included studies predominantly examined ABF production generally (60%) without specifying alternatives employed. Europe accounted for 80% of studies, while Asia accounted for 20%. Consumer awareness of agricultural antibiotic use was consistently low across contexts. Attitudes toward ABF products were favorable with one study reporting WTP premiums of 18–20%. Health consciousness was the strongest predictor of acceptance. Conclusions: The review highlights that while substantial literature exists on ABF products, no studies examine consumer perceptions of specific non-pharmaceutical interventions. Future research should investigate consumer responses to intervention specific labeling and communication strategies. Full article

In this study, we characterized the holin-like protein ORF70 from the cyanophage MaMV-DC, offering valuable insights into its role in phage-mediated host cell lysis. ORF70 shares key features with class III holins, such as a hydrophobic transmembrane domain and membrane-associated localization, which are crucial for its bacteriolytic activity. Subcellular localization studies suggested its association with the membrane, supporting its classification as a holin-like protein. Overexpression of ORF70 in E. coli resulted in significant growth inhibition, increased β-galactosidase leakage, and visual confirmation of cell death through live/dead staining. Additionally, ORF70’s sensitivity to the energy toxin 2,4-dinitrophenol (DNP) further indicated its holin-like activity by promoting membrane depolarization. Transmission electron microscopy and Gram staining revealed characteristic morphological changes in E. coli cells, including membrane disruption, consistent with damage caused by holins. These results suggest that ORF70 acts as a holin-like protein that disrupts the host membrane, leading to bacterial cell death. Our study provides evidence supporting the holin-like activity of ORF70 from cyanophage MaMV-DC. This research significantly enhances our understanding of phage-host interactions and opens new avenues for developing phage-based therapies, offering promising alternatives to traditional antibiotics amidst the growing challenge of antibiotic resistance. Full article

(1) Background: Oat (Avena sativa L.) is a crop that is widely used in human nutrition, while it also plays an important role in animal husbandry as a high-quality forage crop. However, this crop is particularly susceptible to combined biotic stressors, including insect pests (Agriotes lineatus) and fungal infections (Fusarium spp.). These stresses act synergistically: root damage caused by wireworms increases the plant’s susceptibility to fungal infection, while pathogens further limit nutrient uptake and root system development. In recent years, the reduced efficacy of chemical pesticides against both insect pests and fungal pathogens has highlighted the need for alternative strategies in oat protection, leading to an increased focus on developing bacterial bio-inoculants as sustainable and effective biocontrol agents. (2) Methods: This study aimed to identify bacterial strains capable of suppressing wireworms (Agriotes lineatus) and Fusarium spp. in oats, while simultaneously promoting plant growth. Bacterial isolates were screened for key Plant Growth Promoting (PGP) and biocontrol traits, including IAA and siderophore production, phosphate solubilization, and the presence of toxin- and antibiotic-coding genes. (3) Results: The highest insecticidal effect against wireworms was recorded for Bacillus velezensis BHC 3.1 (63.33%), while this isolate also suppressed the growth of F. proliferatum for 59%, F. oxysporum for 65%, F. poae for 71%, and F. graminearum for 15%. The most effective Bacillus strains (with insecticidal and antifungal activity) were identified and tested in two pot experiments, where their ability to enhance plant growth in the presence of insects and fungi was evaluated under semi-controlled conditions. An increase in plant biomass, grain yield, and nitrogen content was observed in oat inoculated with B. velezensis BHC 3.1 and B. thuringiensis BHC 2.4. (4) Conclusions: These results demonstrate the strong potential of both strains as multifunctional bio-inoculants for enhancing oat growth and mitigating the adverse effects of wireworm damage and Fusarium infection. Full article

Burkholderia is a metabolically versatile genus of Gram-negative bacteria that inhabits niches ranging from soil and water to plants and clinical environments. This review provides an integrated examination of Burkholderia species, focusing on their dual roles as both pathogens and beneficial microorganisms. Key pathogenic species, such as members of the Burkholderia cepacia complex and the Burkholderia pseudomallei group, pose significant threats to human, animal, and plant health due to their intrinsic antibiotic resistance and diverse virulence factors. Conversely, several environmental and plant-associated Burkholderia species promote plant growth, enhance nutrient uptake, and serve as biocontrol agents, supporting sustainable agriculture. We synthesize current knowledge across taxonomy, genomics, pathogenicity, beneficial interactions, and secondary metabolite biosynthesis—including the prolific production of antibiotics, toxins, and volatile organic compounds with pharmaceutical and agricultural potential. Advances in high-throughput genomics are revealing substantial genetic diversity, genome plasticity, and mechanisms underlying both pathogenicity and beneficial traits. Clarifying this dual nature and identifying strategies to mitigate risks will guide the safe and effective exploitation of Burkholderia in medicine, agriculture, and biotechnology. Full article

The objective of this study is to evaluate the effects of crude protein (CP) levels and antibiotics in feed on the growth performance, body composition, nutrient digestion and absorption, gut health, and microbiota of weaned piglets. A total of 100 piglets (Duroc × Landrace × Yorkshire, weaned at day 21) with an initial weight of 6.39 ± 0.03 kg were randomly assigned to four treatments and fed with 18% CP antibiotic-free diets, 18% CP with antibiotics diets, 24% CP antibiotic-free diets, and 24% CP with antibiotics diets for 0–14 d (S1). Furthermore, the piglets were fed with an identical diet (19% CP and without antibiotics) starting day 15 until they reached 25 kg (S2). Results indicated that the average daily gain (ADG) and gain feed ratio (G:F) during the S1 phase as well as BW at day 14, were significantly decreased (p < 0.05) in the 18% CP group compared with the 24% CP group. Similarly, piglets in the 18% CP group showed a significantly decreased body protein content and body water, protein deposition rates at the S1 phase, and significantly improved the body lipid content and deposition rate but not (p > 0.05) at the S2 phase. The 18% CP group demonstrated significantly increased (p < 0.05) serum concentrations of Threonine, Valine, Isoleucine, and Lysine in weaned piglets during the S1 phase, while Glycine concentration significantly decreased, and no significant (p > 0.05) effects were observed in the S2 phase. Furthermore, dietary antibiotic supplementation had no effect on (p > 0.05) piglet growth performance, body composition, nutrient digestion, and metabolism throughout the entire trial period. In the absence of antibiotics, compared to the 24% CP diet group, the piglets fed with an 18% CP diet significantly increased the relative abundance of Lactobacillus in the colon of weaned piglets upon reaching 25 kg BW (p < 0.05). Compared to the diet without added antibiotics, the addition of antibiotics to the diet significantly decreased the relative abundance of Pseudoramibacter in the colon of weaned piglets on day 14. No significant (p > 0.05) difference was observed in intestinal morphology or gastrointestinal pH among the groups. In conclusion, lower dietary protein levels in the early post-weaning period reduced growth performance and promoted gut microbiota balance, and compensatory growth occurred after returning to higher protein levels two weeks after weaning. Full article

Efficient, cost-effective and sustainable pork production remains a primary objective in modern pig farming. However, the extensive use of antibiotics in animal nutrition has raised significant concerns regarding food safety and the emergence of antibiotic-resistant bacteria. These challenges have prompted the search for safe and effective alternatives to antibiotic growth promoters. Sodium butyrate (SB), the sodium salt of butyric acid, has gained considerable attention as a functional feed additive in swine production. Its supplementation has been shown to improve intestinal morphology, regulate gut microbiota composition and enhance immune competence, resulting in better nutrient utilization and growth performance. Moreover, SB supplementation may support environmental sustainability in livestock production by mitigating the emission of harmful gases in swine housing facilities. Although current evidence is limited, in vitro studies have reported promising reductions in NH₃, H₂S and total gas production by 17.96%, 12.26% and 30.30%, respectively. Comparable effects have also been observed in laying hens, where NH₃ emissions were reduced by 26.22%. This review summarizes current knowledge on the application of SB in pig nutrition, focusing on its mechanisms of action, effects on health and productivity, and potential environmental benefits. The findings indicate that SB represents a promising and safe alternative to antibiotics, supporting both animal welfare and sustainable pork production within modern livestock systems. Full article

Background: Plant growth promoting bacteria (PGPB) are non-pathogenic bacteria that enhance plant growth through several mechanisms such as nutrient mobilization, phytohormones production, defense against phytopathogens, and alleviation of plant stress. Hence, these bacteria are used as ecologic biofertilizers to diminish the use of agrochemicals. Nevertheless, some PGPR strains can harbor antibiotic resistance determinants and the possibility of spreading them upon releasing these bacteria is an environmental concern. Objectives: The objectives of this work are as follows: (1) evaluating the antibiotic resistance in a collection of PGPB, and (2) prospecting antibiotic resistance genes in the genomes of PGPB in order to predict the risk for antibiotic resistance dissemination. Methods: The resistance towards 12 antibiotics in a collection of 20 PGPB (10 Gram-positive and 10 Gram-negative strains) has been evaluated using disk diffusion in agar, broth microdilution, and agar dilution tests. In addition, the whole genomes of six strains have been sequenced in order to find the correlation between the resistance levels and AMR genes by using bioinformatic tools. Results: The results indicated a wide range of halo diameters, but in general Gram-negatives showed higher resistance compared to Gram-positives. The four most resistant strains and the two more susceptible strains were selected for further analysis and sequencing the whole genomes. The resistant strains were identified as Achromobacter spanius N6, Leclercia adecarboxylata H17, Priestia aryabhattai strain MHA1, and Bacillus cereus N25. The susceptible strains were identified as Pantoea sp. S3 and Priestia megaterium MS4. Mining antibiotic resistance genes in the genomes confirmed the existence of resistance determinants responsible for the phenotypic behavior, indicating the potential of genomics for predicting antibiotic resistance in PGPB. However, there was not an exact correspondence between the presence of the genes and the level of resistance, suggesting the existence of additional regulatory mechanisms. Conclusions: The information obtained by genomics must be complemented experimentally by tests for antibiotic resistance determination. In this regard, it is necessary to develop a global antibiotic resistance database for PGPB, due to the difficulty of interpretation of the antibiotic susceptibility tests after comparing the experimental results with those tabulated for clinical species. Full article