Search Results (1,100)

Endophytic bacteria of the Bacillus subtilis species complex are known for plant growth promotion and antifungal activity, although strain-specific traits remain poorly understood. This study characterized the Bacillus siamensis strain BACIII, isolated from asymptomatic soybean roots in a charcoal rot-affected area, using whole-genome analysis and phenotypic assays. Genome sequencing identified BACIII as Bacillus siamensis and revealed a metabolically versatile genome containing twelve biosynthetic gene clusters linked to antimicrobial compounds such as difficidin, fengycin, and surfactin. Additionally, genomic islands associated with mobile elements, regulation, and stress response suggest adaptive potential. Inoculation with the BACIII strain significantly accelerated germination and increased early growth, biomass accumulation, and chlorophyll content in soybean and sunn hemp (p < 0.05), whereas no significant effects were observed in cotton or sunflower, indicating host-dependent responses. In vitro assays demonstrated consistent inhibition of several phytopathogenic fungi, including Sclerotinia sclerotiorum, Fusarium spp., and Macrophomina phaseolina, with variable intensity. Overall, BACIII combines host-specific plant growth promotion with broad antifungal activity, supporting its potential for biological control in sustainable agriculture. Full article

The Caribbean is a recognized biodiversity hotspot; however, on islands such as Jamaica, many faunal groups of ecological and forensic importance, including flesh flies, remain poorly characterized, particularly at the genetic level. This study represents an initial step towards addressing that gap through DNA barcoding. Forty-four specimens from 16 species were analyzed through partial sequencing of the cytochrome c oxidase subunit I (COI) gene. Of the 44 sequences, 30% shared 97–100% similarity with reference sequences in GenBank and BOLD; however, taxonomic resolution varied between databases. The remaining sequences gave lower similarity matches (88–96%), with assignments restricted to the genus level or higher taxonomic ranks, or were discordant with morphology-based identifications. With one exception, pairwise intraspecific genetic distances were low (0.17%), whereas interspecific distances ranged from 5.68% to 12.83%. Neighbor-joining analysis showed that Jamaican taxa, including five endemic species and two new records, formed largely distinct monophyletic clades relative to sequences from North and South America, Europe and Oceania, with >70% bootstrap support. These findings demonstrate the utility of COI barcoding for species discrimination among Jamaican flesh flies and represent an important step towards establishing a regional DNA barcode library. Expanding Caribbean representation in global databases will be essential for improving the accuracy of molecular identification and resolving uncharacterized taxa. Full article

Biogeographic barriers are well known to structure animal and plant diversity, but whether they are associated with variation in host-associated microbiomes, especially in tropical pollinators, remains poorly understood. Here, we investigated gut bacterial community variation in the stingless bee Tetragonula laeviceps (Apidae: Meliponini) collected from Bali and Lombok, two Indonesian islands situated on opposite sides of the Wallace Line. Using 16S rRNA gene V3–V4 amplicon sequencing, we analyzed 12 colony-level samples collected from forest and agroforestry habitats on both islands. Alpha-diversity analysis revealed variation in bacterial richness and diversity among colonies and sampling groups, with the highest richness observed in the Lombok agroforestry group. The gut microbiota was dominated by Firmicutes, Proteobacteria, Actinobacteriota and Bacteroidota, with several bee-associated genera, including Lactobacillus, Bombilactobacillus, Apilactobacillus, Bombella, Commensalibacter, Snodgrassella, Bifidobacterium and Bartonella, varying in relative abundance among island and habitat groups. Beta-diversity analyses showed significant group-associated differentiation in bacterial community composition (ANOSIM R = 0.444, p = 0.001), indicating that gut microbiome structure differed across the sampled island–habitat groups. Differential-abundance analyses identified candidate bacterial taxa associated with specific groups, suggesting that microbiome divergence was driven mainly by shifts in the relative abundance of shared bacterial lineages rather than complete replacement of dominant taxa. Predicted functional profiling further indicated that the taxonomic variation was accompanied by differences in putative functional potential. These findings suggest that the gut microbiota of T. laeviceps carries a detectable island and habitat-associated signal and highlight host-associated microbial communities as an underexplored dimension of tropical island biogeography. Because island identity and position relative to the Wallace Line are not independent in this design, these results should be interpreted as island associated microbiome variation within a Wallace Line context, not as direct evidence of a causal Wallace Line effect. Full article

Non-aeruginosa Pseudomonas (NAP) species represent a diverse and ubiquitous group of Gram-negative bacteria inhabiting a wide range of environmental niches, from soil and water to plant rhizospheres and clinical settings. While Pseudomonas aeruginosa has historically dominated clinical and research focus, the significance of NAP species, such as Pseudomonas fluorescens, Pseudomonas putida, and Pseudomonas stutzeri, as both opportunistic human pathogens and versatile biotechnological agents is increasingly recognized. Their remarkable genomic plasticity, driven by large accessory genomes and mobile genetic elements, underpins their metabolic versatility and adaptability but also facilitates the acquisition of virulence determinants and antibiotic resistance genes, contributing to their emergence in healthcare settings, particularly among immunocompromised individuals. This review provides a comprehensive analysis of NAP species, focusing on recent advances in their taxonomy facilitated by genomic tools like Whole-Genome Sequencing (WGS) and Multilocus Sequence Typing (MLST), which reveal complex species groups and challenge traditional classifications. We delve into the genomic landscape, exploring pangenome dynamics, horizontal gene transfer (HGT), and the genomic signatures that may differentiate clinical from environmental isolates. The clinical relevance of NAPs is examined, detailing the spectrum of infections, epidemiological trends, risk factors, and insights into virulence mechanisms, including secretion systems (T3SS, T6SS) and pathogenicity islands. Addressing a critical need, this review incorporates detailed sections on the diagnostic challenges posed by NAPs, including common misidentifications and the role of modern techniques like MALDI-TOF MS and WGS, and outlines current and novel therapeutic strategies, considering the growing problem of antimicrobial resistance (AMR) within this group. Furthermore, the biotechnological applications of NAPs in bioremediation and biocatalysis are discussed alongside evolving biosafety considerations, reflecting the shift from strict containment to integrated monitoring approaches for genetically engineered strains. By synthesizing current knowledge and highlighting research gaps, this review underscores the necessity of integrated, One Health approaches to understand and manage the dual nature of non-aeruginosa Pseudomonas species as both environmental inhabitants and clinically relevant pathogens. Full article

Helicobacter pylori possesses an unusually high number of restriction–modification (R-M) systems relative to its small genome, contributing to a methylome increasingly implicated in bacterial gene regulation. In this study, we analyzed the methylomes of two mutant strains of H. pylori 26695: ∆rdxA (control) and ∆rdxA/∆arsS. Each mutant was cultivated under neutral (pH 7) and acidic (pH 5) growth conditions. We identified one conspicuous hypomethylated region of 21 kBp possessing 21 annotated genes across each methylome. Notably, over 600 protein coding regions and 10 different promoters displayed differential methylation between pH conditions, including several virulence factors. The vacA gene, encoding the Vacuolating Cytotoxin A, exhibited eight differentially methylated positions between pH 7 and pH 5 within the H. pylori 26695 control mutant methylome, potentially contributing to its previously documented 32-fold down regulation of mRNA in acidic environments. pH-dependent methylation changes were widespread within the cag pathogenicity island, genes encoding cell envelope proteins including adhesin-encoding sabA, babA, and hopQ, and numerous flagellar-associated genes. These results reveal the plasticity of the H. pylori methylome and suggest that DNA methylation is responsive to environmental pH in both ArsRS-dependent and independent manners. Methylome dynamics may serve as an important layer of gene regulation in acclimation to hostile gastric environments and promote persistent infection. Full article

The Carpathian water buffalo represents a locally adapted but under-characterized genetic group found in Central and Eastern Europe. Genome-wide information on its genetic diversity, population structure and potential adaptive variation remains limited, particularly for Hungarian and Romanian populations. In this study, we genotyped 263 water buffalo individuals from Hungary and Romania using the GeneSeek Genomic Profiler Bovine 100K SNP array to evaluate genetic diversity, the population structure, runs of homozygosity (ROH) and candidate genomic regions showing signatures of selection. After quality control, 214 Hungarian and 33 Romanian individuals and 6605 SNPs were retained for downstream analyses. Both populations showed moderate genetic diversity, with the Romanian population displaying higher minor allele frequency, observed heterozygosity and nucleotide diversity than the Hungarian population. In contrast, the Hungarian buffalo showed a higher burden of runs of homozygosity, including a larger proportion of long ROH segments, suggesting stronger recent autozygosity or a more restricted breeding structure. Principal component analysis and neighbor-joining phylogeny separated the two populations, whereas ADMIXTURE indicated shared ancestry and a within-population substructure rather than complete population-specific differentiation. The integration of standardized F_ST, absolute allele-frequency differences and ROH islands identified six candidate regions under a positive signature of selection in each population. These regions harbored genes previously associated with immune response, reproduction, growth, milk production and thermotolerance in bovids. Functional enrichment was limited, with significant Gene Ontology terms detected only in the Hungarian candidate regions. Our results provide a regional genomic baseline for the future conservation and breeding management of Carpathian water buffalo. Given the use of a cross-species SNP array and unequal sample sizes, the candidate selection signals should be interpreted as hypothesis-generating and warrant validation using higher-density buffalo-specific genomic data. Full article

Sea Island cotton (Gossypium barbadense L.) is a premium raw material for high-end textiles due to its excellent fiber quality. The AP2/ERF transcription factor family plays critical roles in plant growth and hormone signaling. Here, 161 GbERF family members were identified in Sea Island cotton and classified into nine subgroups, with GbERF13 belonging to Group V. Expression analysis revealed that GbERF13 was specifically and highly expressed in fibers, with transcript abundance peaking at 15–30 days post-anthesis (DPA), coinciding with the transition from fiber elongation to secondary wall thickening. Exogenous abscisic acid (ABA) treatment significantly induced GbERF13 expression and inhibited fiber elongation. Heterologous overexpression of GbERF13 in Arabidopsis increased trichome and root hair numbers while suppressing primary root growth, confirming its role in cell elongation and development. A nonsynonymous SNP (A/C) at the 117th base pair of the GbERF13 coding region (GbERF13-117SNP) was identified in 213 Sea Island cotton accessions. Association analysis showed the C allele was significantly and positively associated with fiber length, strength, and uniformity. An allele-specific PCR marker was further developed for molecular breeding. Collectively, GbERF13 acts as a key ABA-responsive transcription factor regulating fiber development, and its functional SNP marker provides a valuable tool for improving Sea Island cotton fiber quality. Full article

Vibrio fluvialis is an important zoonotic pathogen that poses a growing threat to both public health and aquaculture, particularly to shrimp and fish farming. In this study, we report that a seafood-associated V. fluvialis strain, 10M-VF, possesses two genomic islands, SGI1-VfNDM1 and GIflu-1, in addition to hemolysins and type VI secretion systems (T6SSs). SGI1-VfNDM1 is a new member of the Salmonella genomic island 1 (SGI1) and harbors several antibiotic resistance genes. A potential transferable region, ISCR1-trpF-ble_MBL-bla_NDM-1, was observed in SGI1-VfNDM1, suggesting that ISCR1 may have mediated the integration of bla_NDM-1 into this island. Additionally, GIflu-1 represents a novel resistance island. Other GIflu variants carrying resistance genes in Vibrio all possess ISCR2, but their resistance regions vary. This indicates that ISCR2 may contribute to the integration of antibiotic resistance genes into GIflu islands. Notably, not every GIflu variant carries drug resistance genes. To the best of our knowledge, GIflu-1 is a previously unreported resistance island, and no previous report has documented the co-existence of two distinct resistance genomic islands in a single Vibrio isolate. The emergence of such resistance islands in a seafood-borne pathogen raises concerns for the maintenance and potential dissemination of clinically important resistance genes in aquatic food systems and underscores the need for ongoing surveillance of resistance determinants in seafood-borne Vibrio populations from a One Health perspective. Full article

Short-term captivity is widely used in experimental studies but may unintentionally alter host-associated microbiomes, potentially confounding biological interpretation of experimental outcomes. Here, we evaluated the effects of 35 days of captivity on the gut microbiome of Fundulus heteroclitus collected from Long Island Sound (Milford, CT, USA) using 16S rRNA gene sequencing. Comparisons between Field Control (FC) and short-term Captive Treatment (CT) groups revealed a marked reduction in microbial diversity under captive conditions. Observed richness decreased approximately five-fold (Field Control: 1026 features; Captive Treatment: 221 features), and Shannon diversity declined from 8.89 to 5.93. Beta diversity analyses based on UniFrac distances demonstrated clear separation between groups, indicating substantial shifts in community composition. Taxonomic profiling revealed reduced community complexity in captive fish, with increased dominance of Proteobacteria and loss of diverse environmental taxa. Predicted enrichment of pathways associated with stress response, altered respiration, and metabolic flexibility in captivity reflects inferred functional potential rather than direct functional activity. Given the use of pooled samples with limited biological replication, these findings should be interpreted as strong community-level patterns rather than population-level inference. Collectively, these results indicate that short-term captivity alters the F. heteroclitus gut microbiome. Full article

Listeria monocytogenes is a ubiquitous Gram-positive bacterium responsible for listeriosis, a foodborne zoonotic disease affecting humans and animals. Although infection in immunocompetent individuals is often asymptomatic or limited to mild self-limiting gastroenteritis, Listeria monocytogenes may cause severe invasive disease in vulnerable groups, including pregnant women, neonates, elderly individuals, and immunocompromised patients. Although the incidence of listeriosis is relatively low compared with many other foodborne pathogens, the high hospitalization and mortality rates associated with clinical cases make this bacterium a major concern for food safety and public health. The evolutionary success of L. monocytogenes reflects the interaction between a conserved core genome and a dynamic accessory genome shaped by horizontal gene transfer (HGT), ecological selection, and expansion of specific clones. Transient intestinal carriage in humans and animals, potentially influenced by gut microbiome composition, creates ecological interfaces where plasmids, transposons, prophages, and integrative conjugative elements contribute to the exchange of antimicrobial resistance determinants, virulence factors, and stress tolerance systems. Virulence diversification is further influenced by the differential distribution of pathogenicity islands such as LIPI-1, LIPI-3, and LIPI-4 across specific clonal lineages. These evolutionary processes occur across interconnected farm, food-production, environmental, and clinical ecosystems consistent with the One Health framework. Advances in whole-genome sequencing have clarified lineage-specific gene flow, expansion of specific clones, and the dynamics of the resistome and mobilome in L. monocytogenes populations. This narrative review aims to synthesize current knowledge on the mobile genetic elements and ecological interfaces that shape horizontal gene transfer in L. monocytogenes. Its novelty lies in integrating antimicrobial resistance, virulence-associated genomic islands, stress adaptation, and gut microbiome-mediated selection within a One Health and metapopulation framework. The main message of this review is that HGT should be interpreted as a context-dependent contributor to L. monocytogenes adaptation, acting together with clonal background, ecological selection, and mobile genetic elements. Full article

Fermented vegetables in Yunnan Province, China, harbor abundant microbial diversity. However, the development of indigenous starter cultures remains under-utilized. Genomic information regarding Leuconostoc (L.) mesenteroides isolates from this region is particularly scarce. To assess the genomic characteristics of eight L. mesenteroides isolates from traditional Yunnan fermented vegetables, we performed whole-genome sequencing and conducted a comparative analysis with 21 publicly available vegetable-derived genomes. Comparative genomic analysis revealed marked variation in genome size and plasmid content, and pangenome analysis indicated an open configuration. Core-genome multilocus sequence typing (cgMLST) of the eight indigenous isolates showed high allelic diversity, indicating a genetically heterogeneous and non-clonal population. Phylogenomic analysis revealed that the evolutionary relationships among the 29 strains were not strictly correlated with their vegetable sources, suggesting an influence from other factors, such as geographic origin and region-specific processing methods. Similar to the profiles of the 21 publicly available genomes, inactive prophages, intrinsic vancomycin resistance genes, and genomic island fragments were detected in eight isolates, whereas no known virulence genes were identified. Bacteriocin gene clusters varied among strains, while stress tolerance and probiotic-related genes were conserved. Overall, these results provide genomic indications relevant to the safety, adaptability, and fermentation potential of indigenous L. mesenteroides from Yunnan. However, because these functional traits are inferred solely from genomic predictions, subsequent experimental validation is essential to confirm their phenotypic properties and technological efficacy. Full article

DNA methylation is a key mechanism in epigenetic regulation and plays a pivotal role in tumor initiation, progression, and therapeutic resistance. We begin by elucidating how the dysregulation of key DNA methylation enzymes in tumors drives concurrent global hypomethylation and cytosine-phosphate-guanine (CpG) island hypermethylation. This aberrant epigenetic landscape promotes tumorigenesis through silencing tumor suppressor genes and triggering abnormal activation of oncogenic signaling pathways. Notably, DNA methylation is intimately linked to cellular pyroptosis. In particular, the hypermethylation-mediated silencing of pyroptosis effector genes represents a critical epigenetic mechanism underlying acquired drug resistance. Targeting DNA methylation with epigenetic drugs offers a novel strategy to resensitize tumors to chemotherapy, radiotherapy, and immunotherapy. Moreover, advances in nanomedicine have yielded smart platforms for the precise administration of epigenetic modulators and combination therapies. These platforms enable a coordinated “epigenetic priming-pyroptosis execution” strategy, which holds promises for reversing therapeutic resistance and remodeling the tumor immune microenvironment. By integrating DNA methylation regulation, pyroptosis mechanisms, and nano-targeted strategies, this review aims to provide a theoretical framework and novel perspectives for developing innovative, epigenetically driven anti-tumor therapies. Full article

Pathogenicity islands (PAIs) are regions of bacterial genomes that harbor genes encoding virulence factors. Identifying molecules that enhance pathogenicity is crucial for understanding the mechanisms pathogens employ to cause disease and their evolution. Corynebacterium pseudotuberculosis (C. pseudotuberculosis) is a pathogenic microorganism that causes caseous lymphadenitis (CLA) in sheep and goats. Despite its prevalence in Mexico, its genetic material has not been analyzed for virulence factors acquired through horizontal gene transfer. Therefore, the aim of this study was to characterize the complete genomes of Mexican C. pseudotuberculosis strains and identify virulence-related genes harbored with PAIs. Seventeen strains of C.pseudotuberculosis biovar ovis isolated from Mexico were whole-genome sequenced using illumina technology, assembled de novo with SPAdes, and annotated using Prokka. PAIs were predicted with GIPSy based on genomic signatures associated with horizontal gene transfer, including G + C deviation, codon usage, virulence factors, transposases, and tRNA-flanking regions. Positive selection was assessed using POTION v1.2 by identifying orthologous groups enriched in non-synonymous substitutions. This represents the first comprehensive PAI analysis of Mexican C. pseudotuberculosis strains, identifying 14 putative pathogenicity islands harboring 51 virulence-associated genes. Additionally, positive selection analysis identified five coding sequences, including radA and rpiB, that are undergoing adaptive evolutionary changes. These findings elucidate the pathogenic mechanisms and genomic plasticity of Mexican C. pseudotuberculosis strains. They also highlight novel genetic targets for vaccine and therapeutic development against CLA. Full article

Macrococcus is a genus of Gram-positive cocci in the Staphylococcaceae family and a close phylogenetic relative of Staphylococcus. It is not a significant human pathogen but is known to widely colonize different environments, including animal skin and food products. Phylogenetically, Macrococcus is distinct from yet closely related to Staphylococcus, particularly the sciuri group. The species is effectively identified through such molecular markers as hsp60 and 16S rDNA. A key biochemical feature is an identified FAD-dependent oleate hydratase in Macrococcus equipercicus (M. equipercicus). Critically, Macrococcus carries various mobile antibiotic-resistance genes, especially against β-lactams (e.g., mecB, mecD) and macrolides (e.g., mef(F), msr(G)); these genes are located on plasmids, SCCmec-like elements, or resistance islands (e.g., McRI_mecD), which facilitates their horizontal transfer. Surveillance confirms the widespread presence of methicillin-resistant Macrococcus, often with a multidrug-resistant phenotype, in food animals and their products. Although its own pathogenicity is low, Macrococcus acts as a reservoir and transmission platform for resistance genes: through horizontal gene transfer, it can potentially confer resistance to pathogenic Staphylococcus, thereby posing a threat to animal and public health. This review summarizes the basic biological characteristics and drug resistance-related research progress of the genus Macrococcus; it aims to provide a reference for subsequent studies as well as to establish technical support and a theoretical basis for the epidemiological investigation, drug-resistant strain identification, and clinical drug-resistance risk prevention and control of Macrococcus. Full article

Glatiramer acetate (GA) is a first-line disease-modifying therapy for multiple sclerosis (MS) with well-established moderate efficacy and high safety, yet its mechanisms of action remain incompletely understood. DNA methylation plays a significant role in MS development and is modulated by various environmental factors, including therapeutic drugs. In this pilot study, we report the first prospective analysis of genome-wide DNA methylation changes in peripheral blood mononuclear cells (PBMCs) from four female relapsing-remitting MS patients before GA initiation and after approximately four and eight months of therapy. We identified 365 loci that are characterized by differential methylation, distinguishing post-treatment time points from baseline, with significant enrichment in CpG islands, shores, and promoter regions. Two distinct temporal patterns emerged: (1) non-monotonic DNA methylation changes peaking at four months and associated with response to foreign antigenic stimuli, and monotonic changes progressively increasing by eight months and related to mTOR-associated pathways relevant to chronic inflammation and neurodegeneration. Integration of DNA methylation and transcriptomic data revealed significant methylation-expression correlations for eight genes, including HLA-DMA, PDE4A, and SMOX—genes with established roles in MS-associated antigen presentation, immunoregulation, and neuroinflammation. Cell composition of PBMCs remained stable throughout treatment. In general, GA therapy for MS appears to induce dynamic, locus-specific DNA methylation changes in PBMCs, with distinct temporal patterns suggesting a biphasic response of the immune system. However, given that none of the individual DMPs reached genome-wide significance, the results presented in this pilot study strongly require validation in larger independent cohorts. Nevertheless, we believe that our findings provide insights into the immunomodulatory effects of GA and lay the foundation for future hypothesis-driven studies to develop epigenetic biomarkers for therapeutic monitoring and generic GA product assessment. Full article