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PubMed2026

Genome mining of alkaliphilic cyanobacterial consortia: identification of biosynthetic gene clusters in Sodalinema and associated heterotrophs.

Alkaline soda lakes are high-pH environments that host specialized microbial communities with potential for biotechnology and natural product discovery. We characterized three Sodalinema-dominated cyanobacterial consortia enriched from Canadian soda lakes over 510 days. Using hybrid metagenomic sequencing and metatranscriptomics across pH, alkalinity, and temperature gradients, we reconstructed high-quality metagenome-assembled genomes and assessed functional activity. All consortia converged toward cyanobacteria dominance and exhibited temperature optima between 21°C and 30°C. Phylogenetic analysis placed Sodalinema genomes within a distinct clade affiliated with Candidatus Sodalinema alkaliphilum. Genomic analysis indicated complete biosynthetic pathways for vitamin B5, vitamin B7, and the molybdenum cofactor, but incomplete pathways for vitamins B1, B9, and B12, consistent with patterns observed in Sodalinema yuhuli. Metatranscriptomic profiles showed increased expression of genes involved in phycocyanin and carotenoid biosynthesis at pH 10.2 relative to pH 8.5. Biosynthetic gene cluster analysis revealed that most secondary metabolic potential resided in heterotrophic community members. Roseinatronobacter encoded pathways for N-acyl homoserine lactones, osmoprotectants, betalactones, and prodigiosin, while Alkalimonas, Wenzhouxiangella, and members of the Kiloniellales encoded clusters for lanthipeptides, cyclodipeptides, hydrogen cyanide, and pyrroloquinoline quinone. These findings indicate functional partitioning within the consortia and highlight the contribution of heterotrophs to secondary metabolism.IMPORTANCEAlkaline soda lakes contain microbial communities adapted to high pH that remain underexplored for biotechnology. This study focuses on Sodalinema, a filamentous cyanobacterium that dominates enriched consortia from Canadian soda lakes, and its associated heterotrophic partners. We show that while Sodalinema drives primary productivity, heterotrophic bacteria encode most of the pathways for antimicrobial and signaling compounds. These interactions may support community stability and defense against competing microorganisms. By linking genomic potential with gene expression, this work identifies alkaline cyanobacterial consortia as a source of bioactive compounds and provides a framework for exploring extremophilic microbial communities for natural product discovery.

Sodalinema↗

PubMed2026

Contribution of the Arg-33-His replacement in the histidine kinase CpxA to carbapenem and cefiderocol resistance in Serratia marcescens.

OBJECTIVE: The Serratia marcescens ROT_R clinical isolate, which was resistant to almost all β-lactams, including cefiderocol (4 mg/L), was recovered from a neonate 2 months after the isolation of the S. marcescens ROT_S strain that was susceptible to extended-spectrum cephalosporins (ESCs). In this study, we attempted to decipher the mechanism of resistance displayed by the ROT_R isolate. METHODS: The genomes of ROT_S and ROT_R were sequenced using the Illumina and the Oxford Nanopore Technologies. Long and short reads were assembled together, giving rise to a circularized hybrid genome. RESULTS: Genomic comparison between ROT_S and ROT_R disclosed only one mutation (G98A) in the cpxA gene of ROT_R, which led to the Arg-33-His substitution in the histidine kinase of the two-component system CpxA/CpxR. The cpxA alleles of ROT_S and ROT_R were amplified and cloned, thus giving rise to the pCpxA_WT and pCpxA_R33H recombinant plasmids, respectively, which were subsequently introduced into the S. marcescens HatR recipient strain, which lacks functional CpxA. The S. marcescens HatR (pCpxA_R33H) recombinant clone, which produced the altered CpxA_R33H variant, differed from the S. marcescens HatR (pCpxA_WT) recombinant clone, which produced the wild-type CpxA, by enhanced MICs of carbapenems and ESCs, including cefiderocol (1 mg/L). CONCLUSIONS: This study demonstrates that CpxA alteration, such as Arg-33-His substitution, can contribute to cefiderocol resistance. Although it increases slightly the MIC of cefiderocol without resulting per se in clinical resistance, it can contribute, in combination with other additional mechanisms, to achieve a high level of resistance to this siderophore cephalosporin.

Cefiderocol↗

PubMed2026

A Randomized Clinical Trial to Compare Moxifloxacin Versus Azithromycin for the Treatment of Mycoplasma genitalium: The FARTHEST Study.

BACKGROUND: Mycoplasma genitalium (MG) is increasingly characterized by high rates of macrolide and fluoroquinolone resistance. International guidelines recommend resistance-guided therapy; however, access to genotypic testing is limited, and randomized trial evidence is lacking. We assessed the efficacy of moxifloxacin and azithromycin without resistance assays. METHODS: This monocentric, open-label, superiority, randomized controlled trial enrolled adults with MG infection detected by multiplex PCR, randomized 1:1 to receive moxifloxacin 400 mg daily for 10 days or azithromycin 500 mg daily for 6 days. A test of cure was performed ≥28 days after treatment completion. The primary endpoint was microbiological cure in the intention-to-treat (ITT) and per-protocol (PP) populations. Subgroup analyses assessed symptomatic versus asymptomatic infections, doxycycline exposure, re-treatment, and sexual behavior. RESULTS: Among 358 randomized participants, 87.0% of those treated with moxifloxacin and 61.2% of those treated with azithromycin achieved microbiological cure in the ITT analysis (absolute risk difference 25.8%, 95% CI 16.5, 35.2). The superiority of moxifloxacin was confirmed in the ITT and PP populations. Moxifloxacin remained superior across most subgroups, whereas azithromycin showed comparable efficacy only among heterosexual individuals. Doxycycline coadministration did not improve outcomes. Both regimens were well tolerated, with only one case of discontinuation. CONCLUSIONS: Moxifloxacin demonstrated superior efficacy compared to azithromycin for treating MG infection in the absence of resistance testing. These randomized data support the use of moxifloxacin as a first-line option when resistance assays are unavailable and may inform treatment strategies.

Humans↗

PubMed2026

Enrichment of Lysobacter in a long-term organically managed agricultural field with low soilborne disease incidence.

Disease-suppressive soils, in which soilborne pathogens are naturally suppressed, offer a promising model for sustainable crop protection, particularly in organic farming systems where chemical disease control options are limited. Although disease suppression in these soils is considered to rely on biological control, the underlying mechanisms remain poorly understood. In this study, we investigated soil from a long-term organically managed field in Shiga Prefecture, Japan, where soilborne disease incidence has remained consistently low, to identify bacterial community features potentially associated with this field. The 16S rRNA gene amplicon sequencing indicated that this soil harbored a bacterial community distinct from those of nearby agricultural soils. Following the application of organic compounds, the genus Lysobacter, a taxon with known antagonistic activity against plant pathogens, was markedly enriched in response to proteinaceous organic inputs. This enrichment was consistent across sampling times and specific to certain proteinaceous organic inputs, whereas minimal effects were observed on chitin, N-acetyl-d-glucosamine, or cysteine. Broader soil surveys indicated that Lysobacter enrichment was not strictly associated with whether soils had been managed under organic or conventional farming practices. Stepwise multiple regression analysis identified 10 co-occurring bacterial genera that were strongly associated with Lysobacter abundance. These findings highlight condition-dependent Lysobacter enrichment as a characteristic microbial response to proteinaceous organic amendments in this low-disease-incidence field and provide microbial insights that may inform microbiome-based strategies for sustainable soil management.

Lysobacter↗

PubMed2026

Form and function of actin impacts actin health and aging.

The actin cytoskeleton is a fundamental and highly conserved structure that functions in diverse cellular processes, yet its direct contribution to organismal aging remains unclear. Here, we systematically interrogated how genetic and pharmacologic perturbations of actin structure and function influence lifespan and various hallmarks of aging in Caenorhabditis elegans. Whole-animal and tissue-specific knockdown of actin and key actin-binding proteins (ABPs)-arx-2 (Arp2/3), unc-60 (cofilin), and lev-11 (tropomyosin)-led to premature disruption of filament organization, reduced lifespan, and tissue-specific physiological defects. Actin dysfunction also displayed a more "aged" transcriptome using previously validated transcriptomics clocks, and broadly exacerbated many age-associated phenotypes, including mitochondrial dysfunction, lipid dysregulation, loss of proteostasis, impaired autophagy, and intestinal barrier failure. Pharmacological destabilization with Latrunculin A mirrored genetic knockdowns, while mild stabilization with Jasplakinolide modestly extended lifespan, emphasizing that optimal and finely tuned actin function is critical for healthy aging. Finally, analysis of human genome-wide association data revealed that common ACTB polymorphisms correlate with differences in age-related decline in gait speed, suggesting some links between aging and actin across organisms. Taken together, our results provide a comprehensive and publicly accessible resource that maps, for the first time, how changes in actin integrity correlate with diverse aging phenotypes across tissues. This descriptive framework is intended to enable future mechanistic discovery by offering a deep, unbiased dataset that can be integrated with emerging studies to define how actin dynamics can potentially influence aging.

actin↗

PubMed2026

Fourteen-Day Amoxicillin- or Tetracycline-Containing Bismuth Quadruple Therapy versus 14-Day Metronidazole-Based Triple Therapy as the Treatment for Clarithromycin-Resistant Helicobacter pylori Infection: A Multicenter Randomized Controlled Trial.

BACKGROUND/AIMS: Combination therapy comprising a proton pump inhibitor (PPI), amoxicillin, and metronidazole (PAM) is used to treat clarithromycin-resistant Helicobacter pylori in the Republic of Korea, but eradication rates are decreasing due to an increasing incidence of clarithromycin resistance. We compared PAM, bismuth compounds plus PAM (PAM-B), and the combination of PPI, bismuth compounds, metronidazole, and tetracycline (PBMT) to determine whether PAM-B can achieve an eradication rate higher than that of PAM and comparable to that of PBMT. METHODS: This prospective multicenter study enrolled patients with clarithromycin-resistant H. pylori infections in the Busan and Gyeongsangnam-do of the Republic of Korea between December 2022 and February 2024. RESULTS: In the intention-to-treat (ITT) analysis, the eradication rate was significantly lower in the PAM group (68.2%) than in the PAM-B group (84.8%, p=0.024), whereas the difference from the PBMT group (81.8%) was not significant (p=0.070). The rate remained lowest in the PAM group (75.4%) in the per-protocol (PP) analysis (PAM-B, 96.5%, p=0.001; PBMT, 94.6%, p=0.004). Eradication rates were comparable between the PAM-B and PBMT groups in both the ITT (p=0.640) and PP analyses (p=0.633). Nausea and vomiting were significantly less frequent in the PAM-B group than in the PBMT group (6.8% vs 25.0%; p=0.007). Severe adverse events were rare, and all symptoms resolved after treatment discontinuation. CONCLUSIONS: PAM-B yielded eradication rates higher than those of PAM and comparable to those of PBMT, with no significant increase in the incidence of adverse events, suggesting the potential of PAM-B as a first-line treatment for clarithromycin-resistant H. pylori infection. Further large-scale studies are needed to validate these results. Registered retrospectively with the Clinical Research Information Service (CRIS; KCT0012265).

Humans↗

PubMed2025

Detoxifying biotransformation of chloramphenicol by Exiguobacterium sp. CAP4 and its bioaugmentation of chloramphenicol biodegradation in simulated wastewater.

The extensive use of chloramphenicol (CAP) in livestock leads the accumulation of CAP in livestock manures, threatening environmental and human health. Therefore, eliminating or reducing CAP concentration in manures before its re-utilization and application through microbial remediation is necessary. Exiguobacterium sp. CAP4, isolated from the plastisphere in duck manures, was capable of degrading CAP with the biodegradation efficiency of 97.8 % at initial CAP concentration of 5 mg/L within 4 days. A total of twenty-four biotransformation products were determined, including two novel transformation products, TP166 and TP203, enriched the integrity of CAP biodegradation pathways. Furthermore, the biotransformation process was proposed as a detoxifying process through biotransformation products toxicity evaluation. Notably, Exiguobacterium sp. CAP4 successfully colonized in the cow manures after inoculation, and bioaugmented the biodegradation of CAP in virgin cow manures. This study significantly extended our understanding of the CAP biotransformation fate, and provided a promising bacterial strain for bioremediation of CAP containing wastewater in situ.

Chloramphenicol↗

PubMed2026

Temporal shifts in gyrA mutation types and sublineage replacement in ST11 Salmonella enterica serovar Enteritidis over a decade (2014-2023): A genomic epidemiological study in Guangxi, China.

The overuse or abuse of antibiotics drives the global health threat of antimicrobial resistance. Although bans on certain veterinary antibiotics, such as colistin, have proven effective, the impact of fluoroquinolone stewardship on the evolution of the foodborne pathogen Salmonella enterica serovar Enteritidis (S. Enteritidis) remains unclear. Here, we conducted a decade-long (2014-2023) retrospective longitudinal genomic epidemiological analysis of 441 ST11 S. Enteritidis isolates from Guangxi, China, alongside a global reference dataset of 4297 genomes. Our aim was to elucidate the effect of real-world antibiotic stewardship on the shift of gyrA point mutations and lineage distribution. Surveillance identified three global epidemic clade sublineages (GEC-L2, L3, L4), with the multidrug-resistant GEC-L4 (i.e., GC-c or MMC2), characterized by the gyrA mutation with amino acid substitution D87Y, being domestically dominant (70.07%, 309/441). Following China's 2016 ban on the veterinary use of critical fluoroquinolones, the proportion of the highly resistant GEC-L4 sublineage decreased continuously (from 86.84% in 2017 to 56.00% in 2023), while the less resistant GEC-L3 sublineage (i.e., GC-b or MMC1), mainly characterized by gyrA D87G, increased simultaneously (from 13.16% to 44.00%). This phenomenon might be attributed to the fact that the GEC-L4 sublineage exhibited a higher fitness cost compared with the GEC-L3 sublineage, as confirmed by the competition assay. A Random Forest Model validated that the gyrA mutation with amino acid substitution D87Y was the paramount feature for these sublineages' identification. In contrast, global data showed a continuous increase in gyrA mutations (from 8.63% in 2006 to 68.85% in 2024), primarily D87Y (from 1.44% to 31.15%) and D87N (from 4.32% to 22.95%), correlating with rising average fluoroquinolone consumption. This study provides direct genomic evidence that national-level antibiotic stewardship can drive the replacement of highly resistant sublineages with moderately resistant ones. These findings offer crucial scientific evidence for evaluating the impact of antibiotic management policies and inform strategies for the rational use of antimicrobials.

China↗

PubMed2026

Lipid-mediated activation of BLT2 promotes membrane repair to prevent cell death.

Various pathogenic microorganisms produce toxins that create pores in cell membranes, causing cell damage and disrupting the host epithelial barrier. Recently, we reported that mice lacking the G protein-coupled receptor leukotriene B4 receptor 2 (BLT2), which is expressed in vascular endothelial and alveolar epithelial cells, are highly susceptible to pneumolysin (PLY), a pneumococci-generated toxin. Although we clarified the protective roles of BLT2 in vascular endothelial cells, those in alveolar epithelial cells have not been elucidated. Here, we report that lipid mediator 12-hydroxyheptadecatrienoic acid (12-HHT), which is produced by membrane-damaged epithelial cells, prevents cell death by promoting membrane repair through BLT2. BLT2 promoted the release of PLY-bound plasma membranes as extracellular vesicles in a sphingomyelinase-dependent manner. Additionally, BLT2 activated Rac1 and subsequent actin polymerization, leading to resistance to cell death. Furthermore, inhibition of 12-HHT production by aspirin and treatment with a BLT2 antagonist abolished the protective effect of BLT2. These findings provide a new therapeutic strategy for bacterial infection.

Receptors, Leukotriene B4↗

PubMed2026

Comparative evaluation of molecular technologies for the identification of prevalent non-tuberculous mycobacteria in pulmonary infections: a systematic review and meta-analysis.

BACKGROUND: The increasing prevalence of non-tuberculous mycobacteria pulmonary disease (NTM PD) is a burden to public health. Successful management of NTM PD critically depends on accurate species identification and reliable drug susceptibility testing to guide appropriate antibiotic therapy. Emerging molecular technologies offer rapid diagnostic solutions compared to conventional methods, but their performance varies. This study aims to provide a comprehensive evaluation of current molecular techniques for NTM identification and to present a global antibiotic resistance profile. METHODS: A systematic literature search was conducted in PubMed and Web of Science for studies published between 2005 and 2024. Studies applying molecular methods for NTM identification and resistance detection in humans were included. Data on study characteristics, diagnostic methods, sample types, sample sizes, identification sensitivity, and drug susceptibility results were extracted. Meta-analysis was performed using R with the meta4diag package. The quality of included studies was assessed using the QUADAS-2 tool. RESULTS: The analysis included 49 studies on NTM identification and 33 studies on antibiotic resistance. For species identification, all evaluated molecular technologies (MALDI-TOF MS, PCR-based methods, Sequencing, DNA chip, and DNA strip) demonstrated high pooled sensitivities (>0.92). Subgroup analysis revealed that sample type significantly affected performance for MALDI-TOF MS. Preliminary analysis of antibiotic resistance rates revealed varying patterns. For slowly growing mycobacteria, a significantly high Ethambutol resistance rate was observed in M. avium (69.20%). Among rapidly growing mycobacteria, resistance to Imipenem was notable (54.22%), and Clarithromycin resistance varied significantly within the Mycobacterium abscessus complex. CONCLUSION: Emerging molecular technologies have revolutionized the methodology for NTM identification with excellent performance. However, their performance can be influenced by sample type, particularly for MALDI-TOF MS. The alarming and heterogeneous antibiotic resistance patterns also highlight the critical need for rapid and accurate species identification and drug susceptibility testing to inform effective therapeutic strategies. Key messagesMolecular technologies demonstrate high accuracy for NTM identification.Antibiotic resistance is a serious concern with variations among NTM species and subspecies.Rapid and accurate species identification and drug susceptibility testing are crucial for guiding effective clinical management of NTM PD.

Humans↗

PubMed2026

Do wound protectors reduce contamination in total shoulder arthroplasty? A randomized controlled trial.

HYPOTHESIS: Cutibacterium acnes is the most frequent cause of shoulder prosthetic joint infection with skin edges as a source of wound contamination. The primary purpose of this study was to determine if the use of a wound protector device decreases the deep wound bacterial colonization in primary shoulder arthroplasty. The secondary purpose was to assess the effect of device usage on deltopectoral muscle and cephalic vein injury. METHODS: This was a prospective, randomized controlled trial. A total of 100 patients undergoing primary total shoulder arthroplasty were enrolled and randomized into 2 groups: a wound protector group and a control group. Five patients withdrew from the study, leaving 48 patients in the wound protector group and 47 controls. Three deep wound culture swabs were taken after final arthroplasty implantation. The surgeon also graded deltoid, pectoralis major, and cephalic vein injury on a 0-3 scale based on modification to the Tscherne classification of soft tissue injury. The primary outcome of this study was positive culture results for C acnes. Secondary outcomes included total bacterial culture positivity as well as soft tissue injury grades. A subanalysis removing likely contaminant positive cultures (growth >7 days and 1 colony only) was also performed. Comparisons between groups were made using Fisher exact test for categorical outcomes and t tests and Mann-Whitney U tests for continuous variables. RESULTS: The use of a wound protector did not result in any significant differences compared with controls in the rate of positive cultures for C acnes (15% vs. 21%, P = .593) or all bacteria (15% vs. 26%, P = .304). Removing likely contaminant positive cultures did not demonstrate any significant difference in culture positivity (9% vs. 17%, P = .355, for C acnes; 9% vs. 19%, P = .231, for all bacterial species). The wound protector group had better soft tissue injury scores for the deltoid muscle (P < .001) and pectoralis muscle (P < .001). No difference in cephalic vein injury was noted between the 2 groups (P > .05). No difference in surgical time was noted. CONCLUSION: The use of a surgical wound protector device in total shoulder arthroplasty did not significantly decrease bacterial colonization of the deep wound. However, soft tissue damage to the deltoid and pectoralis muscle was less severe in the wound protector group. These findings suggest that this device reduces iatrogenic soft tissue injury.

Humans↗

PubMed2026

Genomic diversity and thermal niches of Aspergillus molds disrupting rind formation of surface-ripened cheeses.

Filamentous fungi play important roles in the development of surface-ripened cheese microbial communities and contribute to the aesthetics and flavors of these products. Much is known about the diversity and ecology of desirable cheese fungi, but our understanding of the natural history of cheese spoilage molds is limited. The goal of this work was to characterize the genomic diversity of Aspergillus species contaminating artisan cheeses and to identify how the abiotic environment of cheese (the substrate itself and temperature) may constrain the growth of Aspergillus. Comparative genomics identified two main species of Aspergillus, A. westerdijkiae and A. ostianus, as the spoilage molds across three different facilities in the Northeastern United States that experienced contamination events. Multiple genomic types of A. westerdijkiae were found across the different cheese production facilities, indicating that these contamination events are not caused by a single clonal strain. All A. westerdijkiae isolates produced ochratoxin A, but concentrations varied greatly across strains. RNA-sequencing of A. westerdijkiae on nutrient-rich lab media (malt extract agar) versus cheese curd agar identified a suite of pathways enriched in expression on cheese, including degradation of amino and fatty acids. Experiments measuring growth over a range of temperatures identified that spoilage Aspergillus species have a higher optimal growth temperature compared to desirable fungal species in cheese rinds and are outcompeted by Penicillium species at temperatures lower than 15°C. Global fungal metabarcoding databases suggest that A. westerdijkiae is not normally found in natural habitats of the Northeastern United States, and it may be introduced to this region.IMPORTANCEOver the past decade, disruptive contamination events of Aspergillus spoilage molds have occurred at cheese production facilities in Massachusetts, Connecticut, and Vermont in the United States, causing aesthetic, flavor, and potential safety issues. Our work highlights independent introductions of different strains of A. westerdijkiae into multiple cheese facilities and suggests that temperature could be used to control the abundance of Aspergillus spoilage molds. Based on our analysis of the global distribution of A. westerdijkiae, it is not invading cheese facilities from local fungal populations and may be a contaminant in materials used for cheese production.

Aspergillus↗

PubMed2026

Proteomics-based analysis of the defense mechanisms of disease-resistant grass carp against Aeromonas veronii.

Sustainable aquaculture of grass carp (Ctenopharyngodon idella, GC) is consistently threatened by bacterial diseases, particularly those caused by Aeromonas veronii. A disease-resistant grass carp (DR-GC) has been developed by backcrossing female gynogenetic GC with normal male GC, exhibiting improved resistance. However, the systemic molecular mechanisms of DR-GC defending against Aeromonas veronii infection remain largely unexplored. Here, a label-free quantitative proteomics approach was employed to systematically compare proteomic profiles across five tissues (intestine, liver, muscle, skin, and kidney) in DR-GC and GC under healthy and infected conditions. The intestine was identified as the central defense tissue, exhibiting the highest number of differentially abundant proteins (DAPs). In DR-GC, A0A3N0YEK7 (small ribosomal subunit protein eS28), A0A3N0YGT8 (ATP synthase-coupling factor 6) and A0A3N0YNS7 (apolipoprotein A-I) were significantly upregulated in intestine, while D5KZW6 (GCHV-induced protein), A0A3N0Z0A1 and Q8JH84 (hemoglobin subunit alpha) were significantly dysregulated across multiple tissues, which playing the critical roles in defense mechanisms at the protein level. Furthermore, cytochrome P450-associated pathways, cytosolic DNA-sensing and RIG-I-like receptor signaling pathways were identified as crucial coordinators mediating immune and metabolic responses. This study provides the first comprehensive proteomic view of multi-tissue defense mechanisms in DR-GC, and identifies key DAPs and pathways for subsequent functional validation.

Animals↗

PubMed2026

Climate and soil shape Daqu wheat quality and seed microbiome via rhizosphere taxa and microbial assembly.

The grain quality and seed microbiome of Daqu wheat are fundamental determinants of Daqu fermentation performance; however, the mechanisms by which cultivation environments influence these traits via rhizosphere microbial communities remain unclear. Bacterial and fungal communities across the bulk soil-rhizosphere-seed continuum of three wheat cultivars grown in four ecoregions were characterized using absolute quantitative amplicon sequencing. The rhizosphere microbiome was treated as a central intermediary, while the response variables were seed microbial diversity and grain-quality traits, including starch content, protein content, and grain hardness. Twelve physicochemical properties of soil and 11 climatic factors were integrated into a multidimensional association framework. Environmental conditions exerted stronger influences on both seed quality traits and microbial diversity than cultivar identity. Distinct regional signatures were also evident in rhizosphere microbiomes, with environmental gradients explaining community variation more effectively than geographic distance. Bacterial communities exhibited greater sensitivity to environmental fluctuations than fungi. Mantel analyses identified available nitrogen, precipitation, and atmospheric pressure as significant drivers of core rhizosphere taxa (P < 0.05). iCAMP revealed that stochastic processes predominantly governed rhizosphere bacterial assembly, whereas stochastic and deterministic mechanisms jointly shaped fungal assembly. Partial least squares path modeling further uncovered a rhizosphere-mediated environment-seed cascade, wherein sunlight intensity and duration, atmospheric pressure, and soil nitrogen directly or indirectly affected seed wet gluten content, grain hardness, and seed microbial diversity through their influences on rhizosphere microbiota. Rhizosphere bacterial diversity was negatively associated with seed bacterial diversity (path coefficient = -0.118, P < 0.05), indicating that rhizosphere communities may shape seed endophytic bacterial assemblages via environmental filtering and competitive interactions. Collectively, these findings elucidate how environments shape the quality and seed microbiomes of Daqu wheat, providing scientific guidance for optimal site selection and the standardized production of high-quality brewing wheat for industrial Baijiu.

Triticum↗

PubMed2026

Alternative genetic codes in bacteria and archaea identified with a fast k-mer-based algorithm.

The genetic code is conserved across all domains of life and is often described as universal. Nevertheless, many exceptions to the "universal" code have now been documented, most of these through manual or semiautomated inspection of highly conserved genes. Modern bioinformatics tools improved our ability to find alternative genetic codes but remain computationally expensive, preventing widespread use on thousands of new species identified by sequencing environmental samples. Here, I report a >100-fold accelerated method for inferring the genetic code directly from assembled genomes and apply it to thousands of previously uncharacterized assemblies from archaea and bacteria. I describe three candidate genetic code variations, one of which, an alternative genetic code used by a family of Asgard archaea, is a unique example of sense codon reassignments for this domain. Identifying genetic code variations is important for understanding evolution of the standard code and improving accuracy of protein databases and open reading frame identification.

Genetic Code↗

PubMed2026

Single-cell transcriptomics reveals heterogeneous stress responses and Mg2+-mediated survival mechanisms in Lactobacillus delbrueckii subsp. bulgaricus during freeze-drying and storage.

Maintaining the viability of lactic acid bacteria during dehydration and subsequent storage remains a significant challenge. Here, we employed single-cell RNA sequencing to reveal the heterogeneous stress responses of Lactobacillus delbrueckii subsp. bulgaricus, identifying seven distinct transcriptional clusters across the liquid culture, freeze-drying, and storage phases. The dominant clusters in the freeze-drying and storage were not completely consistent, showing significant functional differentiation. Genomic stability may be important for survival during freeze-drying and storage, while intracellular energy homeostasis appears important for viability during storage. The magnesium transporter mgtB was highly expressed in clusters tolerant to freeze-drying and storage, suggesting a critical role for Mg2+ homeostasis. Further experimental validation confirmed that Mg2+ treatment significantly bolstered stress resistance, increasing immediate post-freeze-drying survival by over 2-fold (up to 92.90%) and post-storage survival by over 5-fold (up to 5.98%). Proteomic data indicated that Mg2+ supplementation correlated with the maintenance of several biological functions potentially relevant to bacterial survival during freeze-drying and storage, including DNA repair, translation, and central carbon metabolism. These findings provide a map of microbial stress resistance through population heterogeneity and offer a potential strategy that may be adapted for enhancing the stability of other industrial lactic acid bacteria products.

Freeze Drying↗

PubMed2026

Genomic characterization and pathogenicity of ruminant Listeria monocytogenes isolates in a murine oral infection model.

Listeria monocytogenes is a major foodborne pathogen; its ruminant isolates display zoonotic characteristics, causing similar clinical signs in humans, including abortion and encephalitis. However, data on whole genome sequencing and pathogenicity of ruminant L. monocytogenes isolates remain sparse. This study aimed to analyze the genotypic characteristics of L. monocytogenes isolates from ruminants with listeriosis. Furthermore, we assessed the in vivo pathogenicity of four ruminant L. monocytogenes isolates, characterized via whole-genome sequencing-based genetic clustering, in orogastrically inoculated mice. The isolate LM18 (serotype 1/2b, ST224, SL6178) had the lowest lethal dose compared to the other three isolates including previous hypervirulence type (serotype 4b, ST1, SL1) and caused secondary bacteremia in lungs, with sustained bacterial loads in the spleen and liver. Genomic (listeria pathogenicity island -1 and -3) and virulence gene (actA and llsX) mutation analyses associated with virulence suggested from well-recognized studies could not elucidate the virulence of the isolates. SSI-1, which only exists in the isolate LM18 (serotype 1/2b, ST224, SL6178), may help L. monocytogenes survive in the gastrointestinal environment, thereby affecting its virulence. Further research should investigate the role of SSI-1 in the pathogenicity of L. monocytogenes. Moreover, additional studies utilizing larger datasets of ruminant isolates are required to validate our genotypic characterization and to obtain a comprehensive picture of further genotypic differences crucial for L. monocytogenes pathogenicity.

Animals↗

PubMed2026

Liver transcriptome analysis revealed multiple immune processes and lipid metabolism pathways involved in the defense response of the turbot (Scophthalmus maximus) against Aeromonas salmonicida.

Aeromonas salmonicida is a significant pathogen causing notable economic losses in Scophthalmus maximus aquaculture. This study utilized Illumina sequencing technology to examine the transcriptional response characteristics of S. maximus liver at 24 h following A. salmonicida infection. A total of 2363 differentially expressed genes (DEGs) were identified when compared to the negative control group. The immunity-related Toll-like receptor signaling pathway, NOD-like receptor signaling pathway, as well as metabolism-related PPAR signaling pathway and insulin signaling pathway, were notably enriched. Significant differences exist in the expression of key genes within the PPAR pathway, particularly cd36, acsl4a, pparαa, and plin2, all of which mediate the interaction between lipid metabolism and the immune response. These results offer valuable insights into the immunometabolic regulatory mechanism of S. maximus response to A. salmonicida infection.

Animals↗