Inhibition Of Pathogens Research Articles

Additive Effects of Natural Plant Extracts/Essential Oils and Probiotics as an Antipathogenic Topical Skin Patch Solution for Acne and Eczema.

This work leverages the additive antipathogenic effects of natural extracts/essential oils (EOs) and probiotics for the treatment of acne vulgaris associated with Cutibacterium acnes (C. acnes) and eczema complicated by secondary infections with Staphylococcus aureus (S. aureus). Six probiotic strains and various extracts/EOs were evaluated in a large screening to evaluate their potential against both pathogens. Lacticaseibacillus paracasei PCB003 was able to inhibit the growth of both pathogens. For extracts/EOs, Oregano EO had the best antipathogenic effects on both pathogens and did not show any adverse impact on the growth of probiotics, making it suitable for simultaneous use. Using Lactiplantibacillus plantarum PCB011 as a probiotic model, five material formulations were assessed for their suitability to protect probiotic cells within freeze-dried topical patches. Alginate and trehalose (ALG+TRE) and thermoplastic starch (TPS) had the highest probiotic survivability, with ALG+TRE chosen as the final patch material as it was more robust. PCB003 and PCB011 were individually incorporated into the ALG+TRE freeze-dried matrix to form a 6 mm patch; both ALG+TRE (PCB003) and ALG+TRE (PCB011) patches, when used individually, successfully inhibited C. acnes growth by 4.7 and 6.0 mm, respectively, surpassing the performance of commercially available acne patches. The additive effect with 30% Oregano EO further improved pathogen inhibition. For S. aureus, the incorporation of 30% Oregano EO to ALG+TRE (PCB003) increased the size of the inhibition zone more than 10-fold. For C. acnes, the ALG+TRE (PCB003) patch with 30% Oregano EO demonstrated an inhibition zone of 16.3 mm, and the ALG+TRE (PCB011) patch with 30% Oregano EO achieved a 14.3 mm inhibition zone. Genomic analysis confirmed that PCB003 and PCB011 lack antimicrobial resistance determinants, ensuring safety. This study successfully combined probiotics and natural agents to create effective dermatological antipathogenic patches.

Enterobactin inhibits microbiota-dependent activation of AhR to promote bacterial sepsis in mice.

Sepsis is a major cause of morbidity and mortality, but our understanding of the mechanisms underlying survival or susceptibility is limited. Here, as pathogens often subvert host defence mechanisms, we hypothesized that this might influence the outcome of sepsis. We used microbiota analysis, faecal microbiota transplantation, antibiotic treatment and caecal metabolite analysis to show that gut-microbiota-derived tryptophan metabolites including indoles increased host survival in a mouse model of Serratia marcescens sepsis. Infection in macrophage-specific aryl hydrocarbon receptor (AhR) knockout mice revealed that AhR activation induced transcriptional reprogramming in macrophages and increased bacterial clearance and host survival. However, culture supernatants from multiple bacterial pathogens inhibited AhR activation in vitro. We showed that the secreted siderophore, enterobactin, inhibited AhR activation in vitro and increased sepsis mortality in vivo. By contrast, oral or systemic tryptophan supplementation increased survival. These findings show that sepsis survival depends upon the interplay between pathogen inhibition and the activation of AhR by a microbiota-derived metabolite.

Light Regulates Secreted Metabolite Production and Antagonistic Activity in Trichoderma

Secondary metabolism is one of the main mechanisms Trichoderma uses to explore and colonize new niches, and 6-pentyl-α-pyrone (6-PP) is an important secondary metabolite in this process. This work focused on standardizing a method to investigate the production of 6-PP. Ethanol and ethyl acetate were both effective solvents for quantifying 6-PP in solution and had limited solubility in potato–dextrose–broth media. The 6-PP extraction using ethyl acetate provided a rapid and efficient process to recover this metabolite. The 6-PP was readily produced during the development of Trichoderma atroviride growing in the dark, but light suppressed its production. The 6-PP was purified, and its spectrum by nuclear magnetic resonance and mass spectroscopy was identical to that of commercial 6-PP. Light also induced or suppressed other unidentified metabolites in several other species of Trichoderma. The antagonistic activity of T. atroviride was influenced by light, as suppression of plant pathogens was greater in the dark. The secreted metabolite production on potato–dextrose–agar was differentially regulated by light, indicating that Trichoderma produced several metabolites with antagonistic activity against plant pathogens. Light has an important influence on the secondary metabolism and antagonistic activity of Trichoderma, and this trait is of key relevance for selecting antagonistic Trichoderma strains for plant protection.

Antibiotic Activity of Euphorbia grantii from Kirinyaga County, Kenya

Background: Euphorbia grantii is widely used in ethnic medicine for the treatment of diseases such as syphilis, gonorrhoea and wound infections. This study aimed at isolating and evaluating antibiotic activity of E. grantii crude extracts. E. grantii plants samples were collected from Kirinyaga county and crude extracts obtained using methanol, hexane and distilled water. Sensitivity test against Shigella dysentriae (ATCC 13313), Salmonella typhi (6539), Klebsiella pneumoniae (70063), Staphylococcus aureus (25923) and Streptococcus epidermidis (12228) was carried out using agar well diffusion bio assay and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determined. Cytotoxicity of the crude extracts was established using brine shrimp lethality test. The crude extracts contained cardiac glycosides, saponins, tannins, anthroquinones, alkaloids, flavonoids and phenolics. The zones of inhibition of the test pathogens by the crude extracts from Euphorbia grantii varied significantly (F= 5.573 P=0.008197). The MIC varied significantly between hexane, methanol and distilled water crude extracts (F=6.6400 P=0.005). However, the MIC and MBC were not significantly different among the crude extracts (P=0.067). The toxicity of the crude extracts increased with increase in concentration. The crude extracts from E. grantii inhibited growth of the test pathogens. There is need to carry out structure elucidation of the crude extracts.

Metabolic modelling uncovers the complex interplay between fungal probiotics, poultry microbiomes, and diet

BackgroundThe search for alternatives to antibiotic growth promoters in poultry production has increased interest in probiotics. However, the complexity of the interactions between probiotics, gut microbiome, and the host hinders the development of effective probiotic interventions. This study explores metabolic modelling to examine the possibility of designing informed probiotic interventions within poultry production.ResultsGenomic metabolic models of fungi were generated and simulated in the context of poultry gut microbial communities. The modelling approach correlated with short-chain fatty acid production, particularly in the caecum. Introducing fungi to poultry microbiomes resulted in strain-specific and diet-dependent effects on the gut microbiome. The impact of fungal probiotics on microbiome diversity and pathogen inhibition varied depending on the specific strain, resident microbiome composition, and host diet. This context-dependency highlights the need for tailored probiotic interventions that consider the unique characteristics of each poultry production environment.ConclusionsThis study demonstrates the potential of metabolic modelling to elucidate the complex interactions between probiotics, the gut microbiome, and diet in poultry. While the effects of specific fungal strains were found to be context-dependent, the approach itself provides a valuable tool for designing targeted probiotic interventions. By considering the specific characteristics of the host microbiome and dietary factors, this methodology could guide the deployment of effective probiotics in poultry production. However, the current work relies on computational predictions, and further in vivo validation studies are needed to confirm the efficacy of the identified probiotic candidates. Nonetheless, this study represents a significant step in using metabolic models to inform probiotic interventions in the poultry industry.8kJrTXnG6ubMgktD71ewfiVideo

Ammonia nitrogen affects bacterial virulence and conditional pathogenic bacterial growth by regulating biofilm microbial metabolism and EPS secretion in laboratory scale distribution systems.

The control of conditional pathogenic bacteria and inhibition of their virulence factors (VFs) in drinking water distribution systems (DWDSs) is vital for drinking water safety. This study adopted two groups of DWDSs to investigate how ammonia nitrogen affects bacterial VFs and conditional pathogenic bacterial growth in biofilms. Our results indicated that Acidimicrobium (95,916.62±119.24 TPM), Limnohabitans (30,338.81±139.14 TPM), and Sediminibacterium (10,658.01±48.94 TPM) were predominant in the biofilm bacterial community of DWDSs with NH3-N addition. Under these conditions, the abundances of various bacterial metabolites, such as L-glutamate (1.45-fold), 2-oxoglutarate (1.24-fold), pyruvate (2.10-fold), and adenosine monophosphate (AMP, 5.29-fold), were significantly upregulated, which suggested the upregulation of amino acid, carbohydrate, nucleotide, lipid, pyrimidine and purine metabolism. These metabolic pathways accelerated extracellular polymeric substance (EPS) secretion. The protein concentration in EPS also increased to 187.59±0.58μg/cm2. The increased EPS secretion promoted the amide I CO group of the EPS protein to interact with the surface of the DWDSs, thus enhancing the ability of bacteria (especially conditional pathogenic bacteria) to adhere to the pipe surface to form biofilms. Due to EPS protection, the abundance of the adherence subtype of VFs and the plate counts of Pseudomonas aeruginosa increased to 5912.8±21.89 TPM and 655.78±27.10CFU/cm2, respectively. Therefore, NH3-N in DWDSs increased bacterial VFs levels and promoted the growth of some conditional pathogenic bacteria by regulating biofilm microbial metabolic pathways and EPS secretion, ultimately impacting the interaction between EPS and the pipe surface.

Galacto-oligosaccharides alone and combined with lactoferrin impact the Kenyan infant gut microbiota and epithelial barrier integrity during iron supplementation in vitro

Aim: Iron supplementation to African weaning infants was associated with increased enteropathogen levels. While cohort studies demonstrated that specific prebiotics inhibit enteropathogens during iron supplementation, their mechanisms remain elusive. Here, we investigated the in vitro impact of galacto-oligosaccharides (GOS) and iron-sequestering bovine lactoferrin (bLF) alone and combined on the gut microbiota of Kenyan infants during low-dose iron supplementation. Methods: Different doses of iron, GOS, and bLF were first screened during batch fermentations (n = 3), and the effect of these factors was studied on microbiota community structure and activity in the new Kenyan infant continuous intestinal PolyFermS model. The impact of different fermentation treatments on barrier integrity, enterotoxigenic Escherichia coli (ETEC) infection, and inflammatory response was assessed using a transwell co-culture of epithelial and immune cells. Results: A dose-dependent increase in short-chain fatty acid (SCFA) production, Bifidobacterium and Lactobacillus /Leuconostoc /Pediococcus (LLP) growth was detected with GOS alone and combined with bLF during iron supplementation in batches. This was confirmed in the continuous PolyFermS model, which also showed a treatment-induced inhibition of opportunistic pathogens C. difficile and C. perfringens . In all tests, supplementation of iron alone and combined with bLF did not have a significant effect on microbiota composition and activity. We observed a strengthening of the epithelial barrier and a decrease in cell death and pro-inflammatory response during ETEC infection with microbiota fermentation supernatants from iron + GOS, iron + bLF, and iron + GOS + bLF treatments compared to iron alone. Conclusion: Overall, beneficial effects on infant gut microbiota were shown using advanced in vitro models for GOS alone and combined with bLF during low-dose iron supplementation.

Managing tomato bacterial wilt through pathogen suppression and host resistance augmentation using microbial peptide.

The increasing health and environmental risks associated with synthetic chemical pesticides necessitate the exploration of safer, sustainable alternatives for plant protection. This study investigates a novel biosynthesized antimicrobial peptide (AMP) from Lactiplantibacillus argentoratensis strain IT, identified as the amino acid chain PRKGSVAKDVLPDPVYNSKLVTRLINHLMIDGKRG, for its efficacy in controlling bacterial wilt (BW) disease in tomato (Solanum lycopersicum) caused by Ralstonia solanacearum. Our research demonstrates that foliar application of this AMP at a concentration of 200 ppm significantly reduces disease incidence by 49.3% and disease severity by 45.8%. Scanning electron microscopy revealed severe morphological disruptions in the bacterial cells upon exposure to the AMP. Additionally, the AMP enhanced host resistance by elevating defense enzyme activities, leading to notable improvements in plant morphology, including a 95.5% increase in plant length, a 20.1% increase in biomass, and a 96.69% increase in root length. This bifunctional AMP provides dual protection by exerting direct antimicrobial activity against the pathogen and eliciting plant defense mechanisms. These findings underscore the potential of this biologically sourced AMP as a natural agent for combating plant diseases and promoting growth in tomato crops. To the best of our knowledge, this is the first study to demonstrate the use of a foliar spray application of a biosynthesized microbial peptide as biocontrol agent against R. solanacearum. This interaction not only highlights its biocontrol efficacy but also its role in promoting the growth of Solanum lycopersicum thereby increasing overall agricultural yield.

Zonation of the Vitis vinifera microbiome in Vino Nobile di Montepulciano PDO production area

The microbial dimension of the terroir is crucial for wine quality, as microbiomes contribute to plant biofertilization, stress tolerance and pathogen suppression. While microbial terroir can act as a biological signature at large scale, data for local contexts is lacking, hindering the characterization of regional microbial diversity in vineyards. Here, we define the microbial terroir of vineyards across the 12 sub-areas (Additional Geographic Units -AGUs) of the “Consorzio del Vino Nobile di Montepulciano DOCG” PDO area (Italy), a world-renowned wine-producing region. Rhizospheres of Vitis vinifera cultivar Sangiovese and soil samples were collected throughout the 2022 viticultural season and analyzed through an integrated metabarcoding/shotgun metagenomic approach, targeting bacteria and fungi. Wine metabolomics was also perfomed, projecting compositional and functional variations of the microbial terroir at the AGUs level into a corresponding variation in the product metabolic profile. Our findings reveal a unique taxonomic configuration of the Vino Nobile di Montepulciano terroir compared to other vineyards, with microbiomes being “AGU-specific” in taxonomic abundances and plant growth-promoting functions, confirming the potential relevance of characterizing and preserving the microbial terroir to safeguard high-quality traditional wines.

Fungi Endofit sebagai Biokontrol Patogen Utama Tanaman Cabai Merah (Uji Antagonisme dan Mekanisme Secara In Vitro)

Endophytic fungi, particularly dark septate endophytes (DSE), have emerged as a promising and sustainable strategy for mitigating fungal pathogens in chili plants. Effective pathogen management is critical in chili production, as fungal infections can cause significant crop losses, reduce fruit quality, and decrease yield. While the use of endophytic fungi in plant protection has been explored in various crops, the potential of DSE as a biocontrol against fungal pathogens in chili plants remains unknown. The present study aimed to evaluate the effectiveness of DSE fungi as biological antagonists against significant pathogens that cause destructive diseases in chili plants, using in vitro trials. The study was conducted from December 2023 to March 2024 at the National Research and Innovation Agency (BRIN). A completely randomized design (CRD) was employed, with a single factor—DSE treatment. Three treatments included D0 (control), DSE 411, and DSE 471. Four pathogenic species were tested: Fusarium oxysporum (Fo), Phytophthora capsici (Py), Colletotrichum capsici (Cc), and Alternaria sp. (Alt). Inhibition rates (IR) were analyzed using Analysis of Variance (ANOVA), followed by the Least Significant Difference (LSD) test at a 5% significance level. The highest antagonistic activity was observed against C. capsici (Cc), with DSE 411 showing a mean value of IR of 77.54%, whereas DSE 471 exhibited a significantly higher IR of 90.26%. Macroscopic observations revealed the formation of clear zones around both DSE colonies, suggesting the mechanism of inhibition by antibiosis or the production of antifungal compounds. Microscopic analysis using scanning electron microscopy (SEM) revealed specific antagonistic mechanisms, including parasitism and competition, as key factors in pathogen suppression. These findings highlight the potential use of DSE fungi as effective biocontrol agents for managing major diseases in chili plants, offering a promising strategy for sustainable disease management and crop protection.

Engineering seed microenvironment with embedded bacteriophages and plant growth promoting rhizobacteria

BackgroundEngineering the seed microenvironment with embedded bacteriophages and Plant Growth Promoting Rhizobacteria (PGPR) shows promise for enhancing germination, mitigating biotic and abiotic stressors, and improving resilience under challenging environmental conditions. This study aimed to enhance potato seed germination and control bacterial wilt caused by Ralstonia solanacearum and salinity by using novel technology to encapsulate, preserve, and deliver phage therapy and rhizobacteria.ResultsSilk fibroin and trehalose biomaterial combined with the phage P-PSG11 and Pseudomonas lalkuanensis were applied to potato seeds. A pot experiment was conducted to investigate pathogen suppression, salt tolerance, and plant growth enhancement. The combination of silk and trehalose effectively preserved both phage and bacteria for ≥ 8 weeks, maintaining both phage titers and bacterial colony counts. Seeds coated with the P-PSG11 and P. lalkuanensis mixture exhibited the highest germination rate at 93.5%, followed by P. lalkuanensis at 86.3%. In vivo evaluations showed significant increases in root length (72.7%, 61.0%, and 22.5%), plant height (71.5%, 65.1%, and 8.2%), and dry matter (129.1%, 125.7%, and 13.1%) for the P-PSG11 and P. lalkuanensis mixture, P. lalkuanensis, and P-PSG11, respectively. The incidence of wilt was significantly reduced by 88.2% and 81.2%, and salinity was mitigated by 83.3% and 79.2% for the P-PSG11 and P. lalkuanensis mixture and P. lalkuanensis treatment, respectively, compared to the control (p < 0.001). The viability of preserved P-PSG11 and P. lalkuanensis was confirmed after one year using phage titers and bacterial colonies.ConclusionThis innovative approach enhanced plant growth, promoted seed germination, controlled wilt disease, and mitigated soil salinity.

Silk Fibroin Seed Coatings: Towards Sustainable Seed Protection and Enhanced Growth.

Seed coating technology is vital in agriculture, enhancing seed protection and growth. However, conventional coatings often include chemical fungicides that pose environmental risks, highlighting the need for sustainable alternatives. This study explores silk fibroin (SF), a natural biopolymer with excellent film-forming properties, as a potential seed coating agent, addressing its antimicrobial limitations by combining it with the commercial agent CRUISER® and the antimicrobial peptide Nisin. Experimental methods included solution stability analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and growth assessments of wheat seeds. Findings reveal that silk fibroin-CRUISER® (SC) composites form stable β-sheet structures, enhancing the coating's mechanical strength. SF-based coatings improved seedling emergence rates (up to 1.65-fold), plant height (up to 1.05-fold), and root growth (up to 1.2-fold), especially under cold stress. The addition of Nisin further significantly boosted the antibacterial properties, providing sustained pathogen inhibition (p < 0.01). Identifying the optimal concentration of SF was essential for achieving a balance between protection and breathability, a key factor for industrial application. This research provides valuable insights into the development of eco-friendly seed coatings, presenting a viable and sustainable alternative to traditional chemical-based options in agricultural practices.

Deciphering the ABA and GA biosynthesis approach of Bacillus pumilus, mechanistic approach, explaining the role of metabolic region as an aid in improving the stress tolerance

Bacillus pumilus plays an essential role in agricultural applications as a beneficial microbe and for sustainable agriculture production. However, the underlying mechanisms of B. pumilus strains remain unclear as to how they are beneficial for plants as stress tolerant and growth promoters. Bacillus pumilus was isolated from the rhizosphere soil of Artemisia vulgaris. NGS (next-generation sequencing) was performed for the strain to gain new insights into the molecular mechanisms underlying plant-microbial interactions. NGS revealed 3,910 genes, 3294 genes with protein-coding, and 11 functional genomic regions related to diverse agronomic traits including stress tolerance. We identified the two possible phytohormone biosynthesis approaches from metabolic regions1(terpense→diterpense→betacarotene→xanthoxin→ABA)2(terpense→diterpense→geranyl diphosphate →C20 →GA). Several gene clusters related to the biosynthesis of phytohormones, stress tolerance, and agricultural diversification were predicted. The genome provides insights into the possible mechanisms of this bacterium for stress tolerance and its future applications. The genomic organization of B. pumilus revealed several hallmarks of its plant growth promotion and pathogen suppression activities. Our results provide detailed genomic information for the strain and reveal its potential stress tolerance mechanisms, laying the foundation for developing effective stress tolerance strategies against abiotic stress.

Adhesion Properties and Pathogen Inhibition of Vaginal-Derived Lactobacilli.

In the present study, twenty-seven (27) lactobacilli strains, isolated from the vagina of healthy Italian women of reproductive age, were screened for probiotic properties. The strains were evaluated for antagonistic activity against pathogens, adhesion abilities, and potential to displace and/or inhibit the adhesion of previously adhered pathogens as a primary strain selection criterion. Overall, all the tested lactobacilli inhibited at least three pathogens, and the majority of them exhibited antimicrobial activity against Enterobacter cloacae DSM 30054, Pseudomonas aeruginosa DSM 3227, and Pseudomonas aeruginosa DSM 1117. The complete neutralization of antimicrobial activity after cell-free supernatant (CFS) neutralization suggested a pivotal role for lactic acid or other organic acids secreted by the lactobacilli. The strains showed variability in their adhesion levels, but all tested strains adhered to both human colonic epithelial cells (HT-29) and vaginal cells (VK2/E6E7) with adhesion percentages exceeding 1%. The ability to displace or inhibit pathogens was dependent on the pathogen and the lactobacilli strain; the pathogen displacement levels ranged from 9 to 82%, while pathogen exclusion levels varied from 1 to 99%. In conclusion, this study demonstrates the protective effect of vaginal lactobacilli against pathogens and confirms the suitability of the vaginal microbiota as a source of potential probiotic strains. The selected lactobacilli hold promise for the formulation of supplements to enhance genitourinary tract health.

Impacts of nanopolystyrene and/or phoxim exposure at environmentally relevant concentrations on the intestinal histopathology, intestinal microbiota, and metabolome in Eriocheir sinensis

Nanopolystyrene (NP) pollution in aquatic environments has become an increasing concern. Phoxim (PHO), one of the major organophosphorus pesticides, has also been detected in aquatic environments, posing serious health risks to crustaceans. This study aimed to assess the detrimental effects of NP and/or PHO exposure at environmentally relevant concentrations on the intestinal histopathology, intestinal microbiota, and metabolome of adult crabs (Eriocheir sinensis) for 21 days. Our study revealed significant histopathological abnormalities in the intestines. In all the exposure groups, there was a discovery of vacuolar degeneration occurring in epithelial cells. Additionally, the peritrophic membrane exhibited thinning after NP or PHO single exposure, while thickening was observed after co-exposure. Exposure to NP and/or PHO disrupted the intestinal microbiota homeostasis, as evidenced by the proliferation of pathogenic bacteria and suppression of beneficial bacteria. Notably, PHO exposure resulted in increased abundance of pathogenic bacteria (Spiroplasma and Arcobacter) and decreased abundance of beneficial bacteria (Bacteroides). Analysis of the metabolome revealed that exposure to NP and/or PHO led to alterations in the metabolic profile as well as several critical pathways. Among these, the upregulation of arachidonic acid metabolism, ABC transporters, and biosynthesis of amino acids was observed in both NP single exposure and co-exposure, while PHO single exposure downregulated these pathways. Additionally, NP and/or PHO exposure downregulated neuroactive ligand-receptor interaction. Spearman correlation analysis revealed that the significant reduction of some differentially expressed metabolites (DEMs) was potentially regulated by the low-abundance bacterial genera following exposure to NP and/or PHO. And these DEMs have a role in anti-inflammatory or antioxidant properties. Collectively, our results offer novel perspectives on the intestinal toxicity of crustaceans by NP and/or PHO at environmentally relevant concentrations.

Preparation of Multifunctional Nano-Protectants for High-Efficiency Green Control of Anthracnose.

Nanomaterials cannot only act as active ingredients (AIs), but also adjuvants to encapsulate or attach AIs to improve their fungicidal activity. Herein, a hydrophilic and lipophilic diblock polymer (HLDP) is designed and synthesized to prepare a series of HLDP nano-protectants to explore the best HLDP nano-protectant for anthracnose management. These results demonstrate that the HLDP-CS nano-protectant displays the best control effects on mango anthracnose via the direct pathogen inhibition and amplified plant immune responses. The HLDP can be spontaneously conjugated with CS into nanoscale spherical particles through hydrophobic interaction. The complexation of CS with HLDP remarkably improves the deposition and adhesion of CS droplets on mango leaves. The HLDP can interact with mycelium via electrostatic interaction to damage the cell wall/membrane, which can act as an AI to directly suppress the spore germination and mycelial growth. Meanwhile, HLDP can be applied as an adjuvant for CS to amplify the plant immune responses via accelerating the biosynthesis of secondary metabolites and plant hormones. This work reports the multiple missions for nanomaterials in pathogen control, which proposes a novel strategy for designing nano-protectant with dual-synergistic mechanism.

Systemic acquired resistance inducing chemicals mitigate black scurf disease in potato by activating defense-related enzymes.

The potato, being an underground vegetable crop, faces consistent threats from soil- and tuber-borne fungal and bacterial pathogens. Black scurf and stem canker disease caused by the fungal pathogen Rhizoctonia solani Kuhn is a critical global concern in the potato cultivation system. In this study, we evaluated the disease mitigation potential of five systemic acquired resistance-inducing chemicals viz., salicylic acid, jasmonic acid, β-aminobutyric acid, γ-aminobutyric acid and hydrogen peroxide (H2O2). Two common methods, tuber dipping and foliar spray, were utilized in this experiment to evaluate pathogen inhibition on inoculated tubers. The results revealed that all the systemic acquired resistance inducing chemicals were effective in disease suppression in a concentration-dependent manner compared to an inoculated control. Significant differences (P<0.005) were evident among the various treatment combinations, with salicylic acid being the most effective in alleviating black scurf disease. Maximum reduction in disease incidence compared to the control was observed with salicylic acid (57.89% and 73.68%), followed by jasmonic acid (52.63% and 65.78%) and H2O2 (49.99% and 60.52%) under the tuber dipping treatment combinations. Whereas, in the foliar application, the maximum reduction in disease incidence compared to the control was observed with salicylic acid (44.73 and 63.15%), followed by jasmonic acid (42.10 and 60.52%) and H2O2 (39.46 and 52.63%). The tuber dipping treatments were significantly more efficacious (P<0.005) compared to foliar spray for all treatment combinations. The biochemical analysis of defense-related enzymes and metabolites demonstrated the induced resistance activation under these treatments. The activity of peroxidase, polyphenol oxidase, and phenyl ammonia-lyase was significantly higher in treated tubers as compared to inoculated and uninoculated control. The total phenol content was also elevated in treated tubers as compared to the respective control. Altogether, these resistance-inducing chemicals can be successfully included in integrated disease management programs.

Succinate exacerbates mastitis in mice via extracellular vesicles derived from the gut microbiota: a potential new mechanism for mastitis

BackgroundA high grain diet causes an ecological imbalance in the gut microbiota and serves as an important endogenous trigger of mastitis in dairy cows, but the underlying mechanisms are unclear. Our previous study revealed that subacute rumen acidosis (SARA)-associated mastitis has distinct metabolic profiles in the rumen, especially a significant increase in succinate, but the role of succinate in the pathogenesis of mastitis remains unclear.ResultsSuccinate treatment exacerbates low-grade endotoxemia-induced mastitis in mice. Specifically, succinate increased the production of gut microbiota-extracellular vehicles (mEVs) containing lipopolysaccharides, which can diffuse across the damaged intestinal barrier into the mammary glands. Administration of mEVs promotes mammary inflammation via activation of the TLR4/NF-κB pathway.ConclusionsOur findings suggest that succinate promotes mastitis through the proliferation of enteric pathogens and mEVs production, suggesting a potential strategy for mastitis intervention on the basis of intestinal metabolic regulation and pathogen inhibition. The role of mEVs in interspecific communication has also been elucidated.Graphical

Abstract 4137240: MHCII hi LYVE1 lo CCR2 hi Interstitial Macrophages Promote Medial Fibrosis in Pulmonary Arterioles and Contribute to Pulmonary Hypertension

Background: Pulmonary hypertension (PH) is a lethal disease characterized in part by progressive pulmonary arteriole (PA) remodeling. Excessive PA fibrosis and macrophage infiltration are often present in PH, but potential association is obscure. We invesitgated the link between interstitial macrophage (iMΦ) infiltration and PA fibrosis in PH and idiopathic pulmonary arterial hypertension (IPAH). Methods: Lung tissue samples from patients with IPAH (n=11) and experimental PH (sugen-5416 and hypoxia, hypoxia, or monocrotaline, n=5) animals (adult male and female SD rats) were obtained to analyze the extent of fibrosis in PA adventitia and media and their correlation to disease severity. Single-cell RNA sequencing, immunohistological analyses, iMΦs and PA smooth muscle cells (PASMCs) coculture, and transgenic animal experiments were used to investigate the cell heterogeneity and molecular mechanisms by which iMΦs promote PA medial fibrosis. Data in this study were analyzed with unpaired two-tailed t-tests with Welch’s correction, Kruskal-Wallis one-way ANOVA followed by Dunn’s test, RM ANOVA with Geisser-Greenhouse correction, or Pearson correlation test, and p &lt; 0.05 was considered statistically significant. Results: We found that increased collagen deposition and fibrosis in the PA media were correlated with PH severity, and iMΦ medial infiltration may be involved in these pathological processes. Single-cell transcriptomics suggested that ligand-receptor associations between MHCII hi LYVE1 lo CCR2 hi iMΦ and fibroblast-like vascular SMC subclusters contributed to PA medial fibrosis. Mechanistically, MHCII hi LYVE1 lo CCR2 hi iMΦs regulated PASMC phenotypic transition and collagen production through the wingless member 11 (WNT11)/planar cell polarity (PCP) pathway. Deletion of iMΦ-enriched Wnt11 in myeloid cells of PH rats ( Itgam CreERT2 ; Wnt11 fl/fl ) normalized the fibrotic PASMC phenotype and decreased PA medial fibrosis, thereby protecting against PH. Moreover, myeloid-specific C-C motif chemokine receptor 2 ( Ccr2 ) deficiency ( Itgam CreERT2 ; Ccr2 fl/fl ) in PH-PAs inhibited MHCII hi LYVE1 lo CCR2 hi iMΦ infiltration. Conclusions: PA medial fibrosis is a causative factor of PH, and the inhibition of MHCII hi LYVE1 lo CCR2 hi iMΦ pathogenicity or infiltration reverses PA medial fibrosis and thus alleviates PH.

Black Soldier Fly (Hermetia illucens) Microbiome and Microbe Interactions: A Scoping Review.

Black soldier fly (Hermetia illucens, BSF) is farmed worldwide to convert organic waste into usable biomaterials. Studies on the larval microbiome have been carried out to check for symbiotic or pathogenic microbes and their respective functions and fates. Some studies tested these microbes for industrial applications, while others tested the effects of exogenous microbes as probiotics or for substrate pre-processing to improve larval fitness, bioconversion rates, or nutritional qualities. This review examined all peer-reviewed literature on these topics to consolidate many disparate findings together. It followed the PRISMA guidelines for scoping reviews. The results found no evidence of globally conserved core microbes, as diet strongly correlated with gut microbiome, but some genera appeared most frequently in BSF larval guts worldwide regardless of diet. The gut microbes undoubtably assist in digestion, including pathogen suppression, and so microbial probiotics show promise for future investigations. However, the common gut microbes have not been explored as probiotics themselves, which would be a promising direction for future work. The impacts of BSF bioconversion on pathogens varied, so each rearing facility should investigate and manage their pathogen risks independently. The data summarized in this study provide useful reference points for future investigations into BSF-microbe interactions.