Search Results (159)

The rising global food demand requires boosting agricultural productivity without compromising environmental sustainability, especially in the face of intensive agrochemical use and soil degradation. Based on this, strain TRQ67 was isolated from wheat rhizosphere soil in the Yaqui Valley, Mexico, and characterized morphologically, biochemically, and genomically. Strain TRQ67 possesses a genome of 4.04 Mbp across 37 contigs with a G + C content of 46.3%, comprising 4127 coding DNA sequences (CDSs), and was identified as Bacillus velezensis through Overall Genome Relatedness Indices (OGRIs), including Average Nucleotide Identity (OrthoANI = 99.12%) and Genome-to-Genome Distance Calculator (Formula 2: 92.6%). The genome revealed key functional genes associated with auxin biosynthesis (trpABCDEF and yhcX), iron acquisition (dhbABF), nutrient solubilization (gabD, acnAB and pyc), stress response (clpCEPX and pspA), antifungal metabolite synthesis (srfAABCD, fenABCD and bmyABC), chemotaxis and motility (cheABCD, motAB, flgBCDEF, swrC), bacterial fitness (acoABR, acuABC and budABC), exopolysaccharide production (epsDEFHI), sporulation (spo0ABEF) and bioremediation. Predicted gene functions were supported by in vitro phenotypic assays; strain TRQ67 was able to solubilize phosphate (Solubilization Index of 4.1 ± 0.46), biosynthesize siderophores (Production Index of 1.70 ± 0.16), and produce indoles (6.52 ± 0.63 µg mL⁻¹). Furthermore, this strain demonstrated antagonistic activity against phytopathogenic fungi Fusarium languescens and Bipolaris sorokiniana, resulting in reductions in fungal growth area of 87.33% and 89.28%, respectively. These antagonistic effects are consistent with the presence of Biosynthetic Gene Clusters (BGCs) encoding lipopeptides (surfactin and fengycin), polyketides (difficidin, bacillaene and macrolactin H), dipeptides (bacilysin) and siderophores (bacillibactin), as identified through antiSMASH analysis. Finally, the strain significantly improved root (27.63%) and shoot (5.82%) biomass in wheat plants under controlled conditions. These results highlight Bacillus velezensis TRQ67 as a promising microbial inoculant with plant growth promotion capabilities and potential antifungal activity against phytopathogenic fungi, as evidenced by strong in vitro antagonistic activity, supporting its further evaluation for sustainable agricultural practices. Full article

Crop straw is an abundant lignocellulosic resource, but its efficient bioconversion is hindered by the recalcitrant structure of plant cell walls. This study integrated degradation phenotyping, enzyme activity assays, whole-genome analysis, and comparative transcriptomics to link the wheat-straw degradation performance of strain XH2 with its enzymatic and molecular responses. Strain XH2 was isolated from fully decomposed compost collected in Anhui Province, China, selected based on the formation of a distinct hydrolysis halo on CMC-Congo red agar, and deposited in the China Center for Type Culture Collection (CCTCC) under accession number CCTCC M 2025519. Morphological, cultural, phylogenetic, and genomic analyses identified strain XH2 as Streptomyces thermocarboxydus. Its degradation capacity was evaluated during 28 days of cultivation by measuring straw degradation, lignocellulosic components, scanning electron microscopy (SEM), and extracellular enzyme activities. S. thermocarboxydus XH2 caused marked disruption of the wheat-straw surface and achieved a degradation rate of 31.45%. Cellulose and hemicellulose contents decreased from 41.10% to 28.87% and from 30.72% to 16.85%, respectively, whereas lignin decreased from 8.28% to 6.30%. Endoglucanase activity, filter paper activity (FPase, an indicator of total cellulase activity), and xylanase activity peaked on day 7, reaching 35.99, 17.68, and 37.01 U/mL, respectively. Genome analysis revealed multiple genes encoding cellulases and hemicellulases. Comparative transcriptomic analysis after 72 h of cultivation in wheat-straw medium identified 1614 differentially expressed genes relative to Gause No. 1 medium, with major enrichment in ABC transporters and fructose and mannose metabolism. Most genes associated with polysaccharide degradation were upregulated. These findings link the degradation phenotype of S. thermocarboxydus XH2 to its enzymatic and molecular responses and support its further evaluation as a candidate for wheat-straw bioconversion under greenhouse and field conditions. Full article

Foot-and-mouth disease (FMD) is one of the most infectious viral diseases of cloven-hoofed animals. The crucial strategy for FMD control is the combination of animal quarantine and a rapid onsite diagnostic assay capable of differentiation of infected from vaccinated animals (DIVA). Herein, we have developed a lateral flow immunoassay to detect specific antibodies against FMDV non-structural protein (NSP), based on recombinant mu3ABC produced by E. coli as an antibody detector, the so-called mu3ABC strip test. The performance of this test was examined using 366 field serum samples from cattle, pigs, and goats and compared with the commercial ELISA kit, resulting in a diagnostic sensitivity (DSn) and specificity (DSp) of 98.05% and 93.16%, respectively. Additionally, efficacies of this test and commercial ELISA were determined using 200 reference bovine serum samples (100 positives, 100 negatives) classified by the Regional Reference Laboratory for Foot-and-Mouth Disease in South East Asia (RRL). The result reveals that the DSn and DSp of the test were 78% and 91%, respectively, while those for the commercial ELISA kit were 69% and 100%, respectively. The developed mu3ABC strip tests are effective and can be used to differentiate the infected animals in parallel with the sero-surveillance ELISA test. Full article

Background/Objectives: Phenotypic drug tolerance, distinct from genetic resistance, allows Mycobacterium tuberculosis (Mtb) to survive prolonged antibiotic exposure and contributes to treatment failure and relapse. The trehalose recycling pathway, mediated by the LpqY-SugABC transporter, has been implicated as a metabolic “escape” mechanism that sustains Mtb viability under antibiotic and nutrient-limiting stress, making it an attractive target for adjunctive, tolerance-breaking therapeutics. Methods and Results: Here, we conducted a high-throughput phenotypic screen of 50,000 compounds from chemically diverse libraries, using a carbon source-restricted assay that forces Mtb to rely on trehalose uptake for growth, to identify small-molecule inhibitors of this pathway. This approach yielded 23 confirmed hits in Mtb, spanning several chemical scaffolds, including thioureas, propanamides, benzamides, and carboxamides. Using an isogenic set of Mtb wild-type, LpqY-SugABC transposon knockout, and complemented strains, we confirmed that the genetic loss of transporter loss reproduces accelerated killing by isoniazid, rifampicin, and bedaquiline, but not moxifloxacin, and that loss of trehalose recycling sensitizes mycobacteria to oxidative stress. Using orthogonal functional assays, fluorescent trehalose probe (FITC-tre) uptake inhibition and H₂O₂ hypersensitization, thiourea-containing compounds emerged as the candidates most consistent with transporter-specific activity, phenocopying the effects of genetic LpqY-SugABC loss, while biochemical assays against recombinant trehalase (Rv2402) excluded downstream enzymatic inhibition as their mechanism of action. In addition, several hits potentiated rifampicin-mediated killing of intracellular Mtb in THP-1 macrophages, in some cases reducing bacterial burden below levels achieved by monotherapy. Conclusions: These findings indicate that the trehalose recycling pathway is functionally druggable by small molecules identified through unbiased phenotypic screening and nominate thiourea- and propanamide-based scaffolds as priority candidates for further mechanistic characterization, including direct target-engagement studies, and optimization as adjunctive anti-tuberculosis agents targeting drug-tolerant Mtb populations. Full article

Oligosaccharides are plant immune elicitors with recognized roles in seed germination, root development and stress regulation. However, most studies have focused on single oligosaccharides or the independent effects of rhizosphere microorganisms. The coordinated regulation of plant physiological networks and microbial communities by oligosaccharide-based seed coatings remains poorly understood, especially for xanthan oligosaccharides. Here, using wheat root transcriptomics, rhizosphere 16S rRNA sequencing, and physiological assays, we found that a xanthan oligosaccharide composite seed coating significantly improved germination potential, germination rate and seedling vigor. It promoted root and shoot growth under field conditions, optimized the balance of auxin, gibberellin and abscisic acid, activated endosperm hydrolytic enzymes and accelerated nutrient mobilization. Transcriptomics revealed stage-specific regulation of membrane lipid metabolism, hormone signaling, antioxidant defense, carbon/nitrogen metabolism and ABC transporters. Microbiome analysis showed selective enrichment of beneficial genera (Devosia, Paenarthrobacter, Citricoccus), which were positively associated with root nitrogen metabolism and MAPK signaling. Collectively, the coating promoted wheat growth and was associated with stress-related physiological and molecular responses; however, direct stress-challenge and functional-validation experiments are required to verify stress-tolerance mechanisms. Full article

The fungal pathogen Colletotrichum jiangxiense has a broad host range and high destructive potential. It is a major causal agent of brown spot disease in diverse plants. Antifungal mechanisms used by biocontrol fungi against plant pathogens include disruption of cellular structures and cell wall damage, which can lead to protoplast leakage and hyphal lysis. In this study, we investigated the antifungal mechanism of the endophytic fungus Diaporthe novem DJ13 against C. jiangxiense, the causal agent of rhododendron brown spot. DJ13 is an effective biocontrol strain previously isolated by our research group from healthy leaves of Rhododendron pulchrum. Physiological assays showed that treatment with DJ13 fermentation broth increased membrane permeability, elevated MDA content, reduced TCA cycle enzyme activities, and increased AKP activity. These findings suggest impaired membrane integrity, disrupted energy metabolism, and cell wall damage. Transcriptomic analysis of the treated pathogen identified 1680 significantly differentially expressed genes (DEGs), including 961 up-regulated and 719 down-regulated genes. Among these genes, ABC transporter genes were significantly up-regulated, whereas genes involved in membrane structure metabolism were significantly down-regulated. Chitinase genes were up-regulated, whereas α-glucanase genes were down-regulated. DASH family cryptochrome genes were significantly down-regulated, while genes related to reactive oxygen species (ROS) production, including xanthine dehydrogenase, were significantly up-regulated. In addition, FAD-dependent oxidoreductase genes were up-regulated, while respiratory-metabolism-related genes, including trimethyllysine dioxygenase, were down-regulated. Together, the physiological and transcriptomic data provide a correlative framework supporting the hypothesis that the antifungal mechanism of DJ13 fermentation broth may involve the coordinated action of four processes: cell membrane damage, cell wall disruption, oxidative stress, and inhibition of energy metabolism. These findings also identify candidate genes for future functional validation. Full article

Recurrence remains a significant challenge following the treatment of Severe Early Childhood Caries (S-ECC). This study aimed to identify candidate recurrence-related biomarkers for S-ECC and elucidate their potential pathogenic mechanisms. Through metagenomic sequencing of supragingival plaque from 32 children at one month post-treatment, we identified Leptotrichia hofstadii as one of the potential biomarkers for S-ECC recurrence (AUC = 0.8438 for the sequencing set and AUC = 0.75 for the validation set). In vitro dual-species biofilm assays using crystal violet staining and Confocal Laser Scanning Microscopy (CLSM) demonstrated that L. hofstadii promotes early-stage S. mutans colonization and extracellular polysaccharide (EPS) formation through contact-dependent synergistic interactions. Scanning electron microscopy revealed that L. hofstadii may function as a spatial scaffold within dual-species biofilm. Furthermore, this synergy significantly accelerates environmental acidification, leading to earlier attainment of the critical demineralization threshold (pH 5.5). At the transcriptional level, carbohydrate metabolism-related pathways were upregulated in dual-species biofilm, including starch and sucrose metabolism, PTS and ABC transporters. Additionally, the fruA gene, which degrades fructan in EPS was downregulated in the dual-species biofilm compared with S. mutans monoculture. These findings suggest that L. hofstadii facilitates a cariogenic microenvironment by enhancing the metabolic activity of S. mutans biofilms. Collectively, this study identifies L. hofstadii as a potential biomarker for S-ECC recurrence prediction and provides preliminary insights into possible interspecies mechanisms, offering valuable clues for future research into targeted preventive strategies. Full article

Rhodococcus equi (R. equi) primarily induces fatal pulmonary and extrapulmonary pyogenic granulomatous infections in foals, imposing substantial economic burdens on the equine industry. The emergence and spread of multidrug-resistant (MDR) R. equi have led to a therapeutic impasse in clinical settings. Although vaccination is a proven strategy against MDR pathogens, no commercial vaccine is currently available for R. equi. In this study, we employed a bioinformatics approach to systematically identify and prioritize antigenic epitopes derived from R. equi for multi-epitope vaccine design. Using ABCPred, NetMHCpan EL, and IEDB servers, 27 MHC-I and 9 MHC-II epitopes were selected from five previously validated R. equi vaccine candidates: ABC transporter, PBD2, NlpC/P60, Esterase, and M23. These epitopes were coupled with distinct peptide linkers to construct six multi-epitope vaccine constructs, designated V1–V6. The physicochemical properties, antigenicity, immunogenicity, and toxicity of the six vaccine constructs were analyzed, and the V3 and V4 constructs were ultimately selected. Using the HDOCK and Gromacs tools, the intermolecular interactions, binding affinity, and thermal stability of the V3 and V4 constructs with the equine MHC molecules EQCA-I and EQCA-II were evaluated. The results confirm that V3 and V4 exhibit strong binding affinity to EQCA-I and EQCA-II, with stable conformations following binding, indicating theoretical potential to induce humoral and cellular immunity in foals. Recombinant plasmids for V3 and V4 were constructed, and the V3 and V4 proteins were successfully prepared, confirming the feasibility of prokaryotic expression for these vaccine constructs. Immunization assays in SPF BALB/c mice showed that the multi-epitope vaccines elicited robust antigen-specific IgG antibody responses, reflecting preliminary humoral immunogenicity. However, these murine data have translational limitations, as they cannot fully represent equine immune responses. The findings establish a crucial theoretical foundation for the advancement of vaccines targeting R. equi while offering a reference for the design of vaccines against other drug-resistant microbial pathogens. Full article

We developed a smartphone-assisted digital image-based optical biosensor array using a planar glass slide with sensor spots in a 2 × 5 array format for point-of-care multiplex detection of biomarkers. The detection is based on the integration of the capture antibody (Ab^C)-functionalized sensor array with a detection antibody-conjugated gold nanoparticle bioconjugate (AuNP@Ab^D) in the presence of interleukin-8 (IL8) to form a sandwich-type AuNP@Ab^D–IL8–Ab^C nanocomplex on the sensing spot surface. Thus, the colorimetric detection method can be applied to the quantitative analysis of IL8, a clinically relevant pro-inflammatory and pro-angiogenic biomarker. The sensing strategy utilizes digital image-based analysis via ImageJ software (V 1.54 g; Java 1.8.0_345 [64 − bit], Windows 8) to quantify the colorimetric signals generated by the light absorbance of surface-bound gold nanoparticles in response to an IL8 droplet sample of merely 8 μL on the planar glass surface, achieving a low detection limit of 0.23 pg/mL (27 fM) and good reproducibility with a coefficient of variation of 0.95%. Validation using IL8-spiked serum at concentrations of 1 × 10⁻⁹ M and 1 × 10⁻¹⁰ M showed minimal matrix effects with a detection accuracy of 99.5% and 106.1%, respectively. Hence, this low-cost portable digital image-based plasmonic nanoparticle-linked immunosorbent assay serves as an alternative to traditional enzyme-linked immunosorbent assays. Full article

Multidrug resistance (MDR) is defined as resistance to apparently unrelated drugs with different mechanisms of action, a phenomenon that seriously decreases the efficacy of many anticancer therapeutic regimens. MDR is mainly associated with a high expression of ATP-binding cassette (ABC) transporters, including ABCB1, ABCG2, and members of the ABCC subfamily, which actively extrude many anticancer drugs of various classes out of the cells. Protein kinase inhibitors (PKIs) were developed as therapies targeting oncogenic kinases but later appeared to be both substrates and inhibitors of ABC transporters and thus can potentially reverse MDR. This comprehensive review evaluates how PKIs regulate ABC transporters through three key mechanisms: altering expression, modifying subcellular localization, and inhibiting the efflux function. We evaluated the effect of PKIs that target tyrosine and serine/threonine kinases, such as EGFR/ErbB, JAK, VEGFR, BCR-Abl, ALK, FGFR, MEK1/2, B-RAF, BTK, CDK4/6, MET, RET, PDGFR and SYK. We have collected both computational studies and experimental reports, including functional assays, mechanistic studies of inhibition, and structural approaches that have evaluated PKIs’ effects on ABC transporters. We conclude that although PKIs can be ABC substrates, they mainly inhibit drug efflux, with minimal and context-dependent effects on transporter expression or localization. Full article

This study reports the plant-mediated synthesis of copper-oxide-decorated magnetic iron oxide composite (CuO@Fe₃O₄) nanoparticles using Dolomiaea costus extract and their application as nanocarriers for β-galactosidase immobilization. The fabricated nanocomposite exhibited favorable physicochemical properties, achieving an immobilization efficiency of 83%, with enhanced thermal and pH tolerance compared to the free enzyme. Kinetic analysis revealed a modest increase in Km and a 31% decrease in Vmax after immobilization, while maintaining 69% of the catalytic activity, confirming the system’s suitability for industrial lactose hydrolysis. Reusability and storage tests showed 79% retained activity after five cycles and 77% after 60 days at 4 °C. In milk hydrolysis, the immobilized enzyme achieved 77% conversion within 3 h, following pseudo-first-order kinetics. Biocompatibility was evaluated using HepG2 cells via the MTT assay. BDH, MDH, and ABC maintained high cell viability across the tested dilution range of 25–100% (v/v), indicating no detectable cytotoxic effect under the experimental conditions, whereas cisplatin showed marked cytotoxicity with an IC₅₀ of 14.98 µg/mL. These findings demonstrate that the green-synthesized CuO@Fe₃O₄ support provides a safe, reusable, and magnetically recoverable platform for β-galactosidase immobilization, offering a promising sustainable strategy for producing lactose-free dairy products. Full article

The rice stem borer (RSB), Chilo suppressalis, is one of the most destructive rice pests in China and chlorantraniliprole has been extensively used for its control over the past decade. However, the continuous and intensive application of chlorantraniliprole has accelerated the development of resistant RSB populations in field, thereby threatening sustainable rice production. In this study, a field resistant strain of RSB exhibited a 181.76-fold resistance level to chlorantraniliprole compared to a susceptible strain. To explore the potential involvement of ATP-binding cassette (ABC) transporters in chlorantraniliprole resistance, four candidate ABC transporter genes (CsABCC1, CsABCC3, CsABCA3 and CsABCD2) were analyzed in resistant and susceptible strains. Compared to the susceptible strain, the expressional levels of CsABCC1 and CsABCC3 were significantly upregulated by 1.58- and 1.38-fold, respectively, whereas of CsABCA3 and CsABCD2 showed non-significant differences in the resistant strain. RNA interference assays demonstrated that naked dsRNA induced only limited gene silencing, while chitosan-mediated dsRNA delivery significantly improved RNAi efficiency. Following feeding with chitosan-coated dsCsABCC1 and dsCsABCC3, the expression levels of both genes were reduced by 44.63% and 38.49%, respectively, relative to the control and the larval mortality increased following chlorantraniliprole treatment to 63.33% and 56.67%, respectively. In addition, silencing CsABCC1 caused a greater reduction in larval weight after insecticide treatment. These findings indicated that CsABCC1 and CsABCC3 are involved in chlorantraniliprole detoxification and may contribute to resistance. Overall, this study provides evidence for the functional involvement of ABC transporters in chlorantraniliprole resistance and highlights chitosan-mediated RNAi as a promising complementary approach for resistance management within integrated pest management programs. Full article

Weathered serpentinites are extreme lithobiontic environments characterized by oligotrophy, high heavy metal content, and desiccation stress; yet, the adaptive mechanisms of colonizing actinobacteria remain poorly understood. This study aimed to isolate and characterize xerotolerant actinobacteria from serpentinite and to profile their secondary metabolites involved in stress tolerance. Three lithobiontic strains were isolated and identified by whole-genome sequencing (dDDH and ANI) as Rhodococcus oxybenzonivorans SK11, Paenarthrobacter nitroguajacolicus SK18, and Rhodococcus qingshengii SK25. Desiccation tolerance was assessed using PEG-8000, siderophore production on CAS agar with metal substitution (Fe³⁺, Al³⁺, Cu²⁺, Ga³⁺), and biosurfactant activity via emulsification assays. Genome mining identified biosynthetic gene clusters for compatible solutes, siderophores, and biosurfactants. All strains maintained viability at 50% PEG. Compatible solute pathways included ectoine (ectABC) in SK18 and SK25, glycine betaine (gbsAB) only in SK18, and trehalose (TreYZ) and proline (ProABC) pathways in all three. Genome mining of Rhodococcus strains revealed a number of NRPS-dependent clusters, some of which are predicted to encode siderophores (rhodochelin, heterobactins), while SK18 used an NRPS-independent desferrioxamine E pathway together with a unique lanthipeptide cluster. Biosurfactant production was condition-dependent, with SK25 achieving complete emulsification (E₂₄ = 100%) in hexadecane-supplemented medium. These findings demonstrate that weathered serpentinite actinobacteria employ an extracellular molecular repertoire of compatible solutes, siderophores, and biosurfactants to survive extreme oligotrophy, desiccation, and metal stress. Full article

Mycoplasma pneumoniae is a significant pathogen responsible for community-acquired respiratory infections in children and adolescents, with the rising prevalence of macrolide-resistant M. pneumoniae (MRMP), particularly in Asia, presenting critical treatment challenges. Our previous study inferred that a macrolide efflux pump may contribute to macrolide resistance in M. pneumoniae in addition to the common point mutations in 23S rRNA gene. This study aimed to define the specific pump and confirm its role. Through comparative genomic analysis, we identified a candidate gene, MPN_080, encoding an ABC transporter permease, which was further characterized using phylogenetic analysis, AlphaFold-based structural modeling, and biochemical assays. Overexpression of MPN_080 from an erythromycin-resistant isolate in the erythromycin-sensitive M129 resulted in a significant increase in minimum inhibitory concentrations (MICs) from <0.125 µg/mL to 1 µg/mL, while similar overexpression of MPN_080 derived from M129 did not affect MICs. Notably, this resistance mechanism operates independently of M. pneumoniae virulence factors, as evidenced by unaltered colonization capacity in NCI-H292 cells and consistent immune response patterns across both strains. Our findings establish MPN_080 as a novel determinant of macrolide resistance functioning associated with enhanced ATPase activity. These insights into non-classical resistance mechanisms may guide future diagnostic and therapeutic strategies against MRMP. Full article

Saline–alkali soils suffer from severe deficiencies in available phosphorus, and externally added phosphorus is readily immobilized by metal ions in the soil. Therefore, activating inorganic phosphorus in the soil represents a significant challenge. In this study, 35 salt–alkali-tolerant bacteria were isolated from rhizosphere soils (pH 9.20–9.68). Three phosphate-solubilizing strains (HA2, HPA5, and KA1) capable of growing under severe saline–alkali stress conditions (pH 10, 5% NaCl) and possessing multiple plant growth-promoting traits (nitrogen fixation, potassium solubilization, siderophore production, and IAA secretion) were screened and co-cultured to form the microbial consortium HHK. It was hypothesized that this consortium might exhibit synergistic effects, resulting in significantly higher phosphorus solubilization capacity compared to individual strains. The results showed that under saline–alkali stress, the phosphate solubilization capacity of HHK (484.59 ± 15.79 mg/L) was significantly higher than that of any single strain (285.59 ± 12.60 mg/L). Non-targeted metabolomics and enzyme assays indicated that HHK solubilizes P via organic acids (e.g., citric, L-malic acid) and synergistically modulates core metabolic pathways, including ABC transport, TCA cycle, and glycolysis, alleviating oxidative damage and maintaining cellular homeostasis. Short-term soil incubation confirmed that HHK significantly increased available phosphorus (53.67%) and soil fertility, indicating its potential as a biofertilizer. Full article