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Insights into the regulation of the HOTAIR proximal promoter.

HOTAIR (HOX transcript antisense RNA) is a HOXC-cluster long intervening non-coding RNA (lincRNA) whose cancer relevance is tightly coupled to how its transcription is wired into hormone, hypoxia, inflammatory, and developmental signaling. HOTAIR is known to associate with cancer cell proliferation, motility, tumor invasion, and metastasis. The present mini-review focuses on the regulatory architecture and mechanistic complexity of HOTAIR transcriptional regulation, with emphasis on three organizing principles. First, we consider the impact of promoter choice between a canonical proximal promoter (P1), which supports the 2.2-2.4 kb transcript, and an alternative upstream promoter/TSS (P2), which contributes to context-dependent transcription initiation. Second, we examine the long-distance enhancer-promoter communication between HOTAIR distal enhancer and P1/P2. Third, we summarize the recent epigenetic and epi-transcriptomic mechanisms involved in HOTAIR transcript initiation and elongation. A combination of these events determines isoform-specific transcription to govern cell-type-, context-, and cancer specific modulation of HOTAIR expression that promotes tumor formation and cancer progression. Finally, the review proposes how large-scale RNA datasets, long-read sequencing, and isoform-specific studies can refine our understanding of this versatile lincRNA's regulation.

Humans↗

nf-core/pacsomatic: a scalable somatic analytic pipeline using PacBio HiFi data.

MOTIVATION: Pacific Biosciences (PacBio) HiFi long-read sequencing enables robust characterization of complex genomic regions, repetitive elements, and structural variants (SVs) that are often inaccessible to short-read technologies. To fully leverage HiFi reads to advance cancer genomics and epigenetics, researchers require an end-to-end, scalable and optimized bioinformatics workflow. The nf-core framework meets this need by providing rigorously tested, community-curated pipelines that ensure reproducibility, transparency, and broad compatibility across computational environments. RESULTS: We present nf-core/pacsomatic, an automated Nextflow DSL2 pipeline designed for comprehensive paired tumor-normal somatic analysis using PacBio HiFi data. The workflow includes steps for read alignments against reference genome, somatic SNV/indel, SV, and CNV calling, CpG methylation profiling and differential methylation region (DMR) detection. Additional downstream modules support functional annotation, mutational signature analysis, tumor purity and ploidy estimation, and homologous recombination deficiency (HRD) assessment. Utilizing nf-core's modular design and containerized execution, nf-core/pacsomatic provides a stable framework for the reproducible discovery of biological insights. AVAILABILITY: nf-core/pacsomatic is available under the MIT License at nf-core (https://nf-co.re/pacsomatic) and github (https://github.com/nf-core/pacsomatic).

Software↗

ECHO: a nanopore sequencing-based workflow for (epi)genetic profiling of the human repeatome.

SUMMARY: The human genome is dominated by repetitive DNA, whose genetic and epigenetic variation plays a key role in gene regulation, genome stability, and disease. Recent advances in long-read sequencing now enable large-scale, haplotype-resolved, and DNA methylation-informative analysis of the human genome, including on previously inaccessible complex and repetitive regions. However, the comprehensive, simultaneous characterisation of the "human repeatome" remains challenging, largely due to the lack of comprehensive tools integrated in a single pipeline that can capture the full spectrum of variation across diverse types of DNA repeats. Here, we present ECHO, a user-friendly, Snakemake-based pipeline for the "(Epi)genomic Characterisation of Human Repetitive Elements using Oxford Nanopore Sequencing." ECHO provides a reproducible and scalable framework for end-to-end analysis of whole-genome nanopore sequencing data, enabling integrative but also tailored (epi)genetic analyses of the human repeatome. AVAILABILITY AND IMPLEMENTATION: ECHO is freely available at Github: https://github.com/leenput/ECHO-pipeline, with the archived version at Zenodo: https://zenodo.org/records/19068468.

Humans↗

RNA splicing and cardiovascular disease: a guide for cardiologists.

Alternative splicing (AS) is a fundamental RNA processing mechanism, which generates different RNA transcripts and consequently different protein isoforms from a single gene. This increases the diversity of proteins within an organism and can fine-tune biological processes. This review examines how cardiac-enriched RNA-binding proteins establish heart-specific splicing programs governing aspects of cardiac development, function, and disease. Developmentally, coordinated sarcomeric isoform switches underpin the foetal-to-adult transition and further isoform rewiring in ion channel and kinase genes determine electrophysiology and excitation-contraction coupling. AS contributes to the pathogenesis of several cardiomyopathies and emerging datasets suggest that pathological hypertrophy engages distinct splicing signatures compared with physiological hypertrophy. This review summarizes diagnostic and prognostic opportunities arising from bulk, long-read, and single-cell/nucleus transcriptomics, which resolve cell type-specific isoforms and disease-associated switches. Circulating RNA biomarkers (including splice ratios and circularRNAs) may signify myocardial remodelling and arrhythmic risk. Integrative approaches that link AS with proteomics and genomics improve variant interpretation, reveal previously unannotated protein isoforms, and enable tracking of disease progression and therapy response. Finally, an outline of therapeutic strategies to modulate AS in cardiovascular disease (CVD), including antisense oligonucleotides, small molecules, and genome-editing modalities (CRISPR, base, and prime editing), is provided. The major challenges that remain before splice-targeting therapeutics can be targeted to treat cardiovascular disease are highlighted. Lessons from neuromuscular indications establish clinical feasibility of splicing correction and motivate translation to cardiology. Together, mechanistic insight, biomarker development, and therapeutic innovation position RNA splicing as a tractable axis for precision cardiovascular medicine.

Humans↗

Conference report: the third Bacterial Genome Sequencing Pan-European Network conference.

The third Bacterial Genome Sequencing Pan-European Network conference, held in Engelberg, Switzerland (12-15 January 2026), brought together experts from six European countries to discuss the implementation of bacterial genome sequencing in clinical microbiology and public health. Key themes included regulatory frameworks (In Vitro Diagnostic Regulation, General Data Protection Regulation), standardization, quality control, data sharing, economic evaluation, and the integration of artificial intelligence and long-read sequencing into diagnostic workflows. Across presentations, panel discussions, and workshops, participants emphasized that successful implementation of genome sequencing requires more than technical capacity: it depends on robust validation, sustainable funding, interoperable data standards, ethical governance, and interdisciplinary collaboration. The meeting highlighted that sequencing should remain question-driven and clinically meaningful, balancing cost, turnaround time, and public health impact. Overall, the conference reinforced the need for coordinated European efforts to advance responsible, standardized, and sustainable genomic surveillance and diagnostics.

bacterial genome sequencing↗

Genome evolution and long-term demographic history in true crocodiles.

Reference-quality genomes remain scarce for true crocodiles (Crocodylus), limiting comparative analyses of genome evolution and demographic history. Here, we generated and analyzed 2 long-read genomes, 1 for Crocodylus intermedius and 1 for C. niloticus, to investigate genome architecture, coalescent effective population size (Ne), and patterns of molecular evolution across crocodilians. Comparative analyses revealed broadly similar repeat landscapes in both species and extensive macro-synteny with Alligator sinensis, indicating strong structural conservation across crocodilian genomes. Using phased diploid assemblies and MSMC2, we reconstructed historical Ne trajectories and found marked differences between species. Crocodylus intermedius exhibited persistently low Ne throughout most of the late Quaternary, with a pronounced decline during the Late Pleistocene-early Holocene transition. In contrast, C. niloticus showed substantially larger Ne over comparable time intervals. Genome-wide codon-based analyses identified significant heterogeneity in dN/dS (ω) among crocodilian lineages. Crocodylus niloticus showed the lowest genome-wide ω, whereas elevated values in C. intermedius and other lineages were consistent with reduced long-term efficacy of purifying selection under smaller historical population sizes. Branch-site tests identified candidate genes under positive selection in both focal species, with functional categories related to ion transport, endocrine regulation, and cellular signaling. Together, these results provide genomic resources for Crocodylus and support an association between long-term demographic history and genome-wide patterns of molecular evolution across crocodilians.

Animals↗

A chromosome-level, haplotype-resolved genome assembly for the barn owl, Tyto alba.

Recent advances in long-read sequencing have enabled near telomere-to-telomere (T2T) assemblies across diverse taxa. However, avian genomes remain challenging due to numerous microchromosomes, small, typically < 20Mb, DNA molecules that are gene-, GC-, and repeat-rich. As a consequence, microchromosomes are often missing from genome assemblies. Here, we present a chromosome-level, haplotype-resolved genome assembly for the Western barn owl (Tyto alba). Using a trio-binning strategy with Illumina parental reads combined with PacBio HiFi and Oxford Nanopore Technologies data, we generated two phased contig sets. These were scaffolded into 40 linkage groups using a linkage map. Comparative analyses identified unplaced HiFi scaffolds corresponding to microchromosomes, which we integrated into six additional microchromosomes using long reads information. The two assemblies present 46 chromosomes, matching the karyotype of the species. They exhibit strong synteny between parental haplotypes, except for a &#x223c;38 Mb complex region on chromosome 7 containing nested inversions. This high-quality reference provides a haplotype-resolved and chromosome-level genome for Strigiformes, enabling fine-scale studies of structural variation and avian genome evolution.

Tyto alba↗

Interplay between the role of DNA methylation in regulating gene expression and TE-silencing in a reptilian methylome.

DNA methylation is a major component of eukaryotic genomes with an important role in the defence against transposable elements, to transcriptionally silence their activity and prevent transposition. DNA methylation also plays a major role in the regulation of gene expression. This dual role can come into conflict, where DNA methylation in gene regulatory regions becomes perturbed due to transposable element transposition, leading to disruption of gene expression. Here, we describe how this conflict is reflected in DNA methylation patterns in the sand lizard genome where there is recent transposable element activity. Using long-read sequencing technology we show that CpG islands in gene transcriptional start sites are typically hypomethylated and associated with higher gene expression. Outside transcriptional start sites, a majority of CpG islands overlapped transposable elements and were associated with hypermethylation, consistent with a host-defence role in suppressing transposition activity. We identify 605 instances where transcriptional start sites were associated with transposable elements (4.3% of all genes). These instances were far rarer in conjunction with a CpG island, when methylation signatures would be in conflict. Transposable elements were found to be closer to and at higher density the more hypermethylated a transcriptional start site was, suggesting strong selection against selfish genetic elements transposing into hypomethylated transcriptional start sites.

CpG islands↗

A chromosome-level genome of the Nicobar pigeon, Caloenas nicobarica.

The Nicobar pigeon (Caloenas nicobarica), the closest living relative of the extinct Dodo (Raphus cucullatus), is endemic to Southeast Asia with a fragmented distribution across numerous small islands. It suffers from habitat loss, hunting, and predation from invasive species, resulting in its classification as Near Threatened by the International Union for the Conservation of Nature. We have generated a haplotype-resolved and chromosome-level genome assembly of the Nicobar pigeon using a combination of PacBio HiFi long-read sequencing and Arima Hi-C chromatin interaction mapping. This assembly includes two haplotypes, each spanning approximately 1.2 Gb. Haplotype 1 has a contig N50 of 25.2&#xa0;Mb and a scaffold N50 of 79.7&#xa0;Mb, whereas haplotype 2 has a contig N50 of 24.7&#xa0;Mb and a scaffold N50 of 107.9&#xa0;Mb. As the first high-quality genome assembly of any bird in the Columbidae Indo-Pacific clade, this resource provides valuable insights for phylogenetic studies. Furthermore, the phylogenetic proximity of the Nicobar pigeon to the Dodo (R. cucullatus) and the Rodrigues Solitaire (Pezophaps solitaria) offers a unique opportunity to study these extinct species, making this assembly a critical resource for evolutionary studies. It also offers a unique model for studying genetic diversity, adaptation, and speciation in island environments. This genomic resource will not only enhance our understanding of the evolutionary history of the Nicobar pigeon but also serve as a valuable tool for future conservation efforts aimed at preserving this unique species and its fragile island ecosystem.

Animals↗

Chromosome-Level Reference Genome of the Desert Night Lizard Xantusia vigilis.

We present a reference-quality genome assembly for the desert night lizard (Xantusia vigilis). The night lizards (Xantusiidae) are a family of small-bodied lizards found in North America (Xantusia), Central America (Lepidophyma), and Cuba (Cricosaura). The night lizard family has an independent evolutionary history of at least 80 million years from its sister taxa within Scincoidea. The Xantusiids have several unique ecological, behavioral and evolutionary characteristics. For instance, the family contains the only squamate species that form diploid, unisexual, parthenogenic lineages. In addition, most night lizards are viviparous and form stable kin groups that are maintained over multiple years, an unusual life history strategy among lizards. Combining PacBio long-read sequencing, Hi-C, and RNAseq data we developed a reference-quality genome for the desert night lizard, X. vigilis. We assembled a complete mitochondrion and&#x2009;~&#x2009;2.2 Gb nuclear genome, with 20 scaffolds that correlate in size to the X. vigilis karyotype. In addition, we found that X. vigilis chromosome 1 aligns with gene content of both of macrochromosome 1 and microchromosome 9 from a genome assembly of a species in the sister family Cordylidae (Hemicordylus capensis).

Xantusia↗

Reference genome of the Californian trapdoor spider Aptostichus stephencolberti Bond 2008 (Araneae: Mygalomorphae: Euctenizidae).

We present a reference genome assembly for the trapdoor spider Aptostichus stephencolberti. This species, described in 2008, is endemic to the highly fragmented coastal dune habitats of Northern California from Monterey to the San Francisco Bay Area. Trapdoor spiders are ideal taxa for landscape scale genomic studies owing to their extreme site fidelity and limited dispersal capabilities; these same characteristics make them prone to extinction. Genomic studies of species like A. stephencolberti can reveal novel areas of endemism and high conservation value that may not be evident in species with wider ranges and greater dispersal capabilities. As part of the California Conservation Genomics Project, we constructed the A. stephencolberti reference genome from high quality long-read sequences, scaffolded with proximity ligation Omni-C data. The primary assembly comprises 551 scaffolds spanning 3.63 Gbp, a scaffold N50 of 62.2 Mbp and BUSCO completeness of 95.6%. We estimate 52 chromosomes yet find no (TTAGG)n telomer repeats. Expanding the telomeric repeat search finds an ancestral loss of the repeat from all spiders. Automated annotation using the NCBI refseq pipeline and RNAseq data from whole adults finds 14,067 genes with a BUSCO annotation completeness of 95.56%. Repeat annotation identified 77% of the genome to be interspersed repeats. This resource, the first for family Euctenizidae will facilitate future study and resulting conservation actions of A. stephencolberti and other Aptostichus sp. populations associated with the rapidly changing California coastal dune ecosystem.

Aptostichus stephencolberti↗

A novel allele of Sh1 facilitates the development of waxy-sweet corn from waxy corn.

Waxy corn and sweet corn represent 2 major classes of fresh-eating corn, each with distinct sensory attributes and nutritional compositions. Developing a new variety that combines both waxy and sweet traits would address rising consumer demand and expand new market potential. From a fast neutron-mutagenized population of the waxy corn inbred line HB522, we isolated a novel mutant, designated as wx-sweet, whose kernels simultaneously exhibit waxy and sweet characteristics at the milk-filling stage. Through bulked segregant analysis combined with fine mapping, we mapped the causal locus to SHRUNKEN1 (Sh1) on chromosome 9, which was confirmed by an allelism test with a characterized Mu-insertion allele of Sh1. A 7,227-bp Copia-type long terminal repeat retrotransposon insertion was identified in exon 2 of Sh1 in the wx-sweet mutant by long-read sequencing. Consistently, the novel sh1 allele significantly reduced sucrose synthase activity. Genetic and physiological analyses demonstrate that sh1 and wx1 act synergistically to fine-tune carbohydrate metabolism in the endosperm. Integrated transcriptomic and metabolomic profiling uncover extensive transcriptional reprogramming and redirected metabolic flux, leading to substantial accumulation of sucrose and a range of oligosaccharides. These metabolic shifts underlie the unique simultaneous dual waxy-sweet texture in fresh-eating wx-sweet kernels. In summary, our work not only provides valuable genetic resources for breeding next-generation fresh-eating corn but also, for the first time, elucidates the molecular mechanism by which the sh1 and wx1 mutations cooperatively shape the waxy-sweet endosperm phenotype.

Zea mays↗

Convergence and conflict among telomere-specialized transposons across 60 million years of Drosophilid evolution.

The Drosophila telomere is one of the best-studied examples of active transposable elements (TEs) benefiting, rather than harming, the host genome. All Drosophila species lack telomerase, and most species instead have telomeres composed of head-to-tail arrays of specialized retrotransposons. These TEs ostensibly act as mutualists by elongating chromosome ends, but evidence from species closely related to Drosophila melanogaster suggests that telomeric transposons may also antagonize their host genome. Importantly, the limited number of Drosophila species characterized thus far has precluded our ability to delineate idiosyncrasies from universal evolutionary forces and genetic mechanisms that shape the history of these TEs. Here, we have surveyed long-read genome assemblies of more than 100 species of Drosophila, identifying a total of 396 telomeric TE families. Our findings show that these telomere-specialized elements evolve dynamically and also undergo striking convergent evolution: The complete loss of telomeric TEs has occurred repeatedly across the genus, whereas individual telomeric TE lineages have repeatedly lost one of their two protein-coding genes. These elements have also repeatedly undergone horizontal transfer between distantly related Drosophila lineages and have repeatedly captured host gene fragments that promote their selfish suppression of host TE-silencing systems. Furthermore, telomere specialization itself appears to have evolved convergently, as some nontelomeric families have gained the ability to target their insertions to telomeres. These results provide unprecedented resolution into the evolution of these unusual TEs and highlight several novel mechanisms by which they evolve in conflict both with each other and their host genome despite the essential telomere function they provide.

Animals↗

Serotypic and Genomic Diversity of Vibrio anguillarum in Rainbow Trout Farms in Turkey: Implications for Vibriosis Control and Vaccine Candidate Selection.

Outbreaks of vibriosis caused by Vibrio anguillarum are a persistent constraint on rainbow trout (Oncorhynchus mykiss) aquaculture. However, information on the population structure of field strains in Turkey has been lacking. Here, we report the first systematic serotypic, proteomic, and genomic characterization of 23 V. anguillarum isolates collected over 10&#x2009;years from rainbow trout farms located in six major aquaculture regions of Turkey. Serological analyses based on microagglutination, supported by ELISA characterization of hyperimmune sera, identified a clear predominance of serotype O1, whereas isolate V12 exhibited a non-agglutinating, atypical O-antigen profile. Protein profiling (SDS-PAGE) and immunoblotting showed largely conserved whole-cell protein patterns among the isolates, but distinct immunogenic bands at 14, 18, and 40&#x2009;kDa were detected in isolates V18 and V21. Long-read whole-genome sequencing revealed that most Turkish isolates grouped within the global O1 clade, while V12, V25, and V28 isolates occupied more distant branches. Comparative genomics demonstrated a conserved core virulence gene set (RTX toxins, siderophore and iron-uptake systems, motility and adhesion factors, Type VI secretion system), with strain-dependent variation in accessory loci such as anguibactin and T6SS-I. Experimental infections of rainbow trout demonstrated significant differences in virulence among isolates (p&#x2009;<&#x2009;0.05), with the V18 isolate showing high, the V15 intermediate, and the V12 low-mortality rates. By elucidating the relationship among the serotype, immunogenic protein profiles, virulence gene repertoires, and in&#xa0;vivo pathogenicity, this study provides a comprehensive overview of the antigenic and genomic diversity of Vibrio anguillarum isolates from Turkey. Notably, the identification of V18 and V21 as promising candidate strains for further vaccine evaluation, characterized by high virulence and unique immunogenic features, provides a scientific foundation for the development of serotype-specific vaccination strategies to mitigate vibriosis-associated losses in aquaculture.

Animals↗

The cold case of state transition 7 (stt7) mutants of Chlamydomonas reinhardtii, solved by whole-genome sequencing.

The process of State Transitions (ST) corresponds to an STT7 kinase-driven redistribution of the transmembrane LHCII antenna proteins between Photosystem II (PSII) and Photosystem I (PSI), which results from changes in their phosphorylation state. For the past two decades, two LHCII-kinase mutants, stt7-1 and stt7-9, have been instrumental in the study of STs in Chlamydomonas reinhardtii, the former being a null mutant for the kinase but quasi-sterile in crosses, while the latter, although fertile, has a leaky phenotype. Using long-read sequencing, this study further characterized the genetic lesions of the stt7 mutant strains through whole-genome reconstruction and de novo chromosome assembly. In addition, two new stt7 null mutants were generated, one derived by crosses from the original stt7-1 and one obtained by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-associated protein 9 (Cas9) technology. This work provides a comprehensive genomic characterization of the original stt7-1 null mutant, revealing extensive chromosomal rearrangements and high levels of aneuploidy, associated with increased cell size and meiotic dysfunction. Reassessment of their physiology and genetic backgrounds highlights the need for caution in interpreting genetic information. We thus produced more reliable null mutants for the LHCII-kinase, amenable to genetic crosses for the study of STs in a variety of genetic backgrounds.

Chlamydomonas reinhardtii↗

Megamimivirus double-stranded DNA linear genomes flanked by highly diverse terminal inverted repeats.

UNLABELLED: Giant viruses have fundamentally expanded our understanding of virology by challenging the conventional boundaries of both virion size and genome complexity. However, the scarcity of isolates has left many of their unique biological features unexplored. Here, we report the isolation and characterization of four new giant virus species belonging to the subfamily Megamimivirinae, sampled from distinct environments across China. Among these, Megavirus daqingense is the first giant virus isolated from an oil reservoir; it exhibits virion stability under high salinity, chloroform exposure, and elevated temperatures, suggesting fitness adaptations to subsurface conditions. Using a hybrid sequencing approach that integrates short- and long-read technologies, we assembled complete linear genomes for all four isolates, each flanked by long terminal inverted repeats (TIRs). Comparative genomic and synteny analyses identified 29 distinct TIRs from 46 megamimivirus genomes. Gene content within these TIRs was highly diverse, with no orthologous proteins conserved across all repeats. Furthermore, TIR genes experienced weaker purifying selection than those in non-TIR regions (i.e., the genomic regions excluding the TIRs), consistent with their role as drivers of genome plasticity. Notably, we discovered for the first time that identical tRNA genes are shared between TIRs and non-TIR regions of eukaryotic viruses. Collectively, our work provides insights into the structural and evolutionary complexity of megamimiviruses, revealing TIRs as reservoirs of genetic diversity and hotspots for gene transfer, thereby playing a pivotal role in shaping the dynamic architecture of giant virus genomes. IMPORTANCE: Terminal inverted repeats (TIRs) are critical structural elements at the termini of linear genomes essential for fundamental processes such as recombination, replication, and integration across diverse organisms. However, the inherent limitations of short-read sequencing technologies have left the complete structure, diversity, and evolutionary significance of long TIRs in giant viruses unexplored. In this study, we leverage hybrid sequencing and comparative genomic analyses to unveil the complexity of TIRs across the subfamily Megamimivirinae. We demonstrate that TIRs are dynamic genomic hotspots characterized by remarkable gene diversity and unexpected conservation of specific tRNA genes. These findings establish TIRs as key drivers of genome plasticity, serving as hotspots for horizontal gene transfer and genetic innovation. By resolving the long-hidden terminal structures of megamimivirus genomes, this work provides a foundational framework for understanding how TIRs shape the evolution of giant viruses and, more broadly, advances our understanding of genome architecture in large DNA viruses.

Megavirus↗

Optimizing a culture-enriched hybrid metagenomics pipeline to assess the AMR footprint of livestock manure in anaerobic digestate.

The role of environmental samples from livestock production systems, including manure and anaerobic digestate, as reservoirs of antimicrobial resistance genes (ARGs) is likely underestimated because conventional metagenomic approaches can overlook low-abundance ARGs and often lack the resolution to associate these genes with their microbial hosts and co-localized mobile genetic elements (MGEs). We evaluated whether culture-enriched metagenomics (CEMG), with and without antibiotic selection, enhances ARG detection in anaerobic digestate and improves the resolution of ARG-MGE-host associations using hybrid short- and long-read metagenomic assembly. CEMG increased ARG recovery; mean ARG abundance rose from 15.4 counts per million (CPM) in metagenomic fresh digestate (FD) to 124 CPM in CEMG without antibiotics and 160 CPM in antibiotic-selective CEMG. In FD, only 9 unique ARGs were detected, whereas CEMG recovered 112, including ARGs of clinical importance, such as glycopeptide resistance, beta-lactamase genes, and the cfr 23S rRNA methyltransferase conferring cross-resistance to multiple antibiotic classes. Antibiotic selection induced targeted, class-specific shifts in ARG profiles, with ARGs associated with tetracycline resistance consistently enriched across treatments. Hybrid metagenomic assembly resolved the genomic context of 784 ARGs, of which 59.3% were co-localized with at least one class of MGEs, predominantly plasmids and integrative conjugative elements/integrative mobilizable elements. Biocide and metal resistance genes frequently co-occurred with ARGs on the same contigs. Together, these findings demonstrate that antibiotic-selective culture enrichment enhances resistome surveillance by improving detection of low-abundance ARGs, while hybrid assembly provides critical genomic context for assessing their mobility and host associations.IMPORTANCELivestock manure and its byproducts, such as anaerobic digestate, are recognized as important environmental reservoirs of antimicrobial resistance genes (ARGs) and resistant bacteria, yet current metagenomic approaches may underestimate this risk by failing to detect low-abundance but clinically relevant ARGs. Here, we show that integrating culture enrichment with hybrid metagenomics improves ARG recovery and reveals ARG co-localization with mobile genetic elements and putative bacterial hosts. This approach captures a cultivable and condition-responsive fraction of the resistome that is not readily accessible through direct metagenomic sequencing alone, providing a more informative framework for environmental AMR surveillance.

anaerobic digestion↗

Coexistence of carbapenemase and hypervirulence-associated genes among Klebsiella pneumoniae high-risk clones in Hungary.

INTRODUCTION: Strains of Klebsiella pneumoniae carrying hypervirulence and carbapenemase genes represent a rapidly emerging global public health threat. Our study aimed to comprehensively characterise the genomics of hypervirulence-associated and carbapenemase genes carrying K. pneumoniae (hv(a)CpKp) isolates in Hungary. MATERIALS AND METHODS: Between January 2022 and April 2024, 89 aerobactin (iucA-D/iutA)-positive non-duplicate carbapenemase-producing K. pneumoniae isolates from 15 Hungarian healthcare institutes underwent short-read (Illumina, MiSeq, NextSeq) whole-genome sequencing, followed by detailed plasmid analysis using long-read sequencing (Nanopore, MinION) in a representative subset of 32 strains. RESULTS: Most isolates (79/89) belonged to the high-risk clone ST147. Hypervirulence-associated (hva) genes-including rmpA/rmpA2, peg344, shiF, iucA-D, and iutA-were universally present, and 59 isolates possessed chromosomally integrated yersiniabactin loci. Most isolates (87/89) carried the bla NDM-1 carbapenemase gene. Hypervirulence-associated genes were most frequently (29/32) associated with IncHI1B/IncFIB(Mar) plasmids. Notably, we identified plasmids carrying both hva and carbapenemase genes-designated as hybrid plasmids-in 13 of 32 strains. The bla NDM-1 was linked to the IS26 transposase and was present in conserved, identical cassettes on all bla NDM-1-carrying plasmids. DISCUSSION/CONCLUSION: Our study identified hv(a)CpKp strains, particularly the ST147 clone, circulating in Hungary. Our findings highlight the need for routine virulence gene monitoring and continuous genomic and plasmid-based surveillance to mitigate the clinical and epidemiological impact of emerging hv(a)CpKp lineages.

Klebsiella pneumoniae↗