Biology subjects

Ponsero, A. J.

Publications and source records attributed to Ponsero, A. J..

11 recordsLinked to original sources

bioRxiv2026

Soil viral response to drought disturbance and ecosystem recovery in an artificial rainforest

Anthropogenic climate change is driving increased temperature and altered precipitation patterns in tropical rainforests, yet the impact of severe drought on soil viral communities and their recovery capacity remains poorly understood. Soil viruses can exert strong controls on bacterial populations impacting microbially-mediated soil processes such as carbon cycling. At the same time, viruses are very sensitive to changes in the soil environment. We leverage meta-omics data from soils collected during a two-month drought and one-month recovery experiment carried in the Biosphere 2 Tropical Rainforest artificial biome. Our results indicate that soil viral community structure responds to small scale soil habitat heterogeneity more strongly than on overall changes in moisture. Additionally, the abundance of soil viruses was associated with a higher diversity of metabolites in the soil, suggesting viruses play a key role in soil biogeochemical processes. Altogether, our study suggests that soil viruses are an active part of tropical rainforest soil microbial communities and that is necessary to understand their response to drought.

microbiology↗

bioRxiv2026

Defining the ESKAPE pathogen prophage repertoire with PHORAGER

Prophages are major drivers of bacterial evolution, mediating horizontal gene transfer and lysogenic conversion to alter host phenotypes. Nevertheless, identifying prophages within bacterial genomes remains challenging due to their heterogeneity and similarity to other mobile genetic elements. Here we present PHORAGER (Prophage Hunting, vOtu Retrieval, Annotation and Genomic ExploRation), a scalable Nextflow pipeline for the standardised identification and quality assessment of prophages from bacterial genomes. PHORAGER incorporates bacterial genome pre-processing, consolidation of predictions from multiple mining tools, annotation-based filtering to reduce false positives, and generation of ready-to-analyse summary tables. We validated PHORAGER using 30,824 publicly available ESKAPE pathogen genomes. PHORAGER recovered more high-quality prophages than individual mining tools alone, and through extensive quality assessments removed a substantial number of false-positive predictions. In total 23,132 putative prophages were identified, the majority belonging to the class Caudoviricetes, and exhibiting a high degree of host-specificity. Putative antimicrobial resistance genes were detected in 0.48% of prophages, whereas virulence factors were most abundant in S. aureus prophages. ESKAPE prophages also frequently encoded anti-phage defence systems. PHORAGER is freely available as open-source software and the ESKAPE prophage collection generated in this study provides a reusable resource for further investigations. GRAPHICAL ABTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/742953v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@1ce582org.highwire.dtl.DTLVardef@11fc004org.highwire.dtl.DTLVardef@17765f5org.highwire.dtl.DTLVardef@1c6f0ff_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioinformatics↗

bioRxiv2026

Bacteriophage genomics: What has five years of INPHARED taught us?

Bacteriophages are key drivers of microbial ecology and evolution, and the rapid expansion of phage sequencing has created sustained demand for curated reference genome databases. We released the INfrastructure for a PHAge REference Database (INPHARED) in January 2021 to provide quality-controlled metadata for complete phage genomes from cultured isolates. Here, we compare the 2021 and 2026 snapshots, spanning a five-year period that included a substantial overhaul of bacterial virus taxonomy by the ICTV. The database has approximately doubled, from 14,244 to 28,777 genomes, yet the proportion representing novel species-level diversity has declined, indicating that redundant sequencing is outpacing new discovery. Host bias persists despite the addition of 97 new host genera. We have incorporated genome quality assessments, lifestyle predictions, and defence and anti-defence system annotations, providing an updated resource and a snapshot of the current state of phage genomics.

microbiology↗

bioRxiv2026

Microbiome stability in wild and rehabilitated insectivorous bats revealed by shotgun metagenomics

BackgroundWildlife rehabilitation can influence host-associated microbiota, yet little is known about how the gut microbiome of insectivorous bats responds to rehabilitation during temporary managed care. This study applied shotgun metagenomics to evaluate the impact of temporary managed care on the gut microbiome of wild and rehabilitated bats in Yorkshire, UK. ResultsWe analysed 25 faecal metagenomes from Myotis daubentonii, Pipistrellus pipistrellus, Nyctalus noctula and N. leisleri, including wild baseline bats and bats sampled during temporary managed care (1-49 days in rehabilitation). Microbial communities clustered strongly by host species and roost location, but not by rehabilitation status. Bacterial alpha diversity did not differ between wild bats, and bats in care (H = 2.30, p = 0.32). Archaeal communities were highly uniform across samples, showing far lower interindividual variation than bacterial communities (12.2% vs. 41.8% coefficient of variation). Rehabilitated bats showed increased relative abundance of Yersiniaceae and Lactobacillaceae, while environmental families such as Pseudomonadaceae and Erwiniaceae decreased, indicating modest but non-disruptive changes consistent with a controlled diet and reduced environmental exposure. ConclusionsAcross temporary managed care, the core gut microbiome of insectivorous bats remained stable, demonstrating notable microbial resilience. These findings provide an important baseline for monitoring microbiome health in wildlife rehabilitation and supporting post-release conservation programmes in the UK and beyond.

microbiology↗

bioRxiv2026

A Systematic Benchmark of Antibiotic Resistance Gene Detection Tools for Shotgun Metagenomic Datasets

1.Accurate detection of antimicrobial resistance genes (ARGs) from metagenomic data is essential for understanding resistance dissemination within microbial communities, yet tool performance remains influenced by sequencing coverage, community complexity, and dataset variability. In this study, we systematically benchmarked five widely used read-based ARG detection tools (ARGprofiler, KARGA, ARIBA, GROOT, and SRST2) across simulated metagenomic datasets representing varying sequencing coverages, microbial complexities, and approximate realistic metagenomic dataset. The results demonstrated that sequencing coverage is a major determinant of ARG detection accuracy, with reliable detection achieved at 10x coverage and performance stabilizing between 20x and 30x. ARGprofiler exhibited the highest overall F1-score (0.891 at [≥]10x), whereas KARGA showed higher recall at low coverage levels, but lower precision compared to ARGprofiler. Increasing community complexity led to a decline in accuracy across all tools, and under realistic uneven coverage, performance variability increased substantially, with KARGA achieving the highest mean F1- score (0.122 {+/-} 0.067). Runtime evaluation further revealed substantial differences in computational efficiency, with ARGprofiler, SRST2, and GROOT being the most resource-efficient, while KARGA imposed the highest computational burden. Collectively, these findings highlight that both sequencing coverage and community complexity profoundly shape ARG detection outcomes and that tool selection should balance accuracy with computational efficiency. The study also emphasizes the need for standardized benchmarking datasets that reflect true metagenomic complexity to ensure robust and comparable ARG surveillance across analytical pipelines.

bioinformatics↗

bioRxiv2025

Infant gut microbiota in multi-child families converges with adults without a sibling-specific signature

The human gut microbiota undergoes rapid development during early life. Sibling presence has been associated with altered infant microbiota composition and accelerated maturation, but distinguishing direct microbial transmission between siblings from confounding by maternal reproductive history (parity) remains challenging. We analysed >5,000 faecal samples from >800 mother-father-infant triads in the Finnish HELMi birth cohort to characterise microbiota patterns that could inform underlying mechanisms. While sibling presence was associated with accelerated microbiota maturation and modest compositional differences, infants who both had siblings (or both lacked siblings) were no more similar to each other than mixed pairs. Instead, infants with siblings exhibited non-specific convergence with adult microbiota profiles and contributed fewer unique genera to their family metacommunities (infant-mother-father triads). Multi-child families harboured smaller but compositionally distinct metacommunities. These patterns challenge simple models of direct sibling transmission and suggest that multiple factors associated with family structure may jointly influence infant microbiota development, though specific mechanisms remain unclear.

microbiology↗

bioRxiv2025

Bacteriophage diversity declines with COPD severity in the respiratory microbiome

Chronic obstructive pulmonary disease (COPD) severity correlates with airway microbial dysbiosis, yet bacteriophage roles remain unexplored. We characterised the lung virome by re-analysing 135 sputum metagenomes from 99 COPD patients and 36 healthy controls. We identified 1,308 viral operational taxonomic units, revealing progressively lower viral diversity correlating with disease severity. Whilst viral and bacterial diversity typically showed strong positive correlations, patients with frequent exacerbations uniquely exhibited decoupled viral-bacterial relationships, indicating disrupted ecological dynamics. Phages infecting anaerobic oral bacteria showed disproportionately lower abundance--Porphyromonas phages were 40-fold less abundant despite only 4-fold lower bacterial abundance--whilst pathogen-associated phages showed no significant differences. We detected virulence factor-encoding phages, including two neuA-carrying Haemophilus phages in 7.4% of Haemophilus-colonised patients, associated with 82-fold higher bacterial abundance. These findings establish altered bacteriophage ecology as an unrecognised feature of COPD pathobiology, with differential phage-bacteria relationships that reshape lung microbial ecosystems, offering new perspectives for microbiome-targeted interventions.

microbiology↗

bioRxiv2025

Life-Stage Transitions Drive Distinct Gut Viral Communities in Dairy Cattle

Ruminant gut microbial communities profoundly influence host health and environmental impacts, yet their viral components remain poorly characterised across developmental transitions. Here, we analysed the dairy cow gut virome across four life stages--calf, heifer, dry adult, and lactating adult. Using hybrid sequencing, we assembled 30,321 viral operational taxonomic units, including 1,338 complete genomes representing mostly novel lineages. Virome composition shifted dramatically with life stage, transitioning from low-diversity, temperate-dominated communities in calves to high-diversity, lytic-dominated communities in adults. Virome transitions paralleled but showed distinct dynamics from bacterial community development, with viral and bacterial diversity negatively correlated during drying-off. Dry cows exhibited elevated viral loads relative to their bacterial hosts. We identified 26 viral sequences targeting the methanogen Methanobrevibacter, absent in calves but present in adults. These findings reveal the dynamic nature of ruminant gut viral communities and highlight phages potential regulatory role during critical life transitions.

microbiology↗

bioRxiv2025

Differences in the genomic potential of soil bacterial and viral communities between urban greenspaces and natural arid soils

Urban green spaces provide essential ecosystem services are ever more important in arid cities. However, the design and management of these greenspaces often require physicochemical transformations whose effect in the balance of the arid urban ecosystems is normally not accounted for. In this project, we leverage metagenomic data from soil microbial communities of urban greenspaces and neighboring natural areas in a city from the arid Southwestern USA (Tucson, Arizona) to understand the differences in microbial (bacterial and viral) community structure and function in urban greenspaces compared to natural arid soils. We found bacterial and viral communities to be distinct between urban greenspace and natural arid soils, viral communities showing a starker differentiation. Urban greenspace bacteria were less versatile and showed higher genetic potential for the simple carbohydrate consumption and nitrogen reduction. Moreover, bacteria in urban greenspaces exhibit higher genetic potential for resistance to heavy metals, and certain clinical antibiotics. Our results suggest that the conversion of arid natural land to urban greenspaces determines the soil microbiome structure and functioning, and potentially its ability to adapt to the changing environment. IMPORTANCEUrban green spaces are critical for the sustainability of arid cities. Nevertheless, they require deep soil physicochemical transformations. Soil bacterial and viral communities are responsible for soil functioning and provision of some ecosystem services, but they are also highly influenced by changes in the soil environment. The significance of our research is in illustrating the structural and functional changes that microbial and viral communities undergo in urban soils of arid cities, and their potential impacts on urban greenspace soil processes.

ecology↗

bioRxiv2024

The Aggregated Gut Viral Catalogue (AVrC): A Unified Resource for Exploring the Viral Diversity of the Human Gut

Despite the growing interest in the role of the gut virome in human health and disease, identifying viral sequences from human gut metagenomes remains computationally challenging due to underrepresentation of viral genomes in reference databases. Several recent large-scale efforts have mined human gut metagenomes to establish viral sequence catalogues, using varied computational tools and quality control criteria. However, there has been no consistent comparison of these catalogues quality, diversity, and completeness, nor unification into a comprehensive resource. Here, we systematically surveyed nine previously published human gut viral catalogues, assessing their quality and the overlap of the viral sequences retrieved. While these catalogues collectively screened >40,000 human fecal metagenomes, 82% of the recovered 345,613 viral sequences were unique to one catalogue, highlighting limited redundancy. We further expanded representation by mining 7,867 infant gut metagenomes, retrieving 1,205,739 additional putative viral sequences. From these datasets, we constructed the Aggregated Gut Viral Catalogue (AVrC), a unified modular resource containing 1,018,941 dereplicated viral sequences (449,859 species-level vOTUs). Detailed annotations were generated for sequence quality, taxonomy, predicted lifestyle, and putative host. The AVrC reveals the gut viromes substantial unexplored diversity, providing a pivotal resource for viral discovery. The AVrC is accessible as a relational database and through a web interface allowing customized querying and subset retrieval, enabling streamlined utilization by the research community and future expansions as novel data becomes available. Author summaryThe human gut is home to a vast array of viruses, collectively known as the gut virome, which play a crucial role in human health and disease. Recently, several research groups aiming at providing an overview of the Human gut viral diversity, have created catalogues of viral sequences found in the human gut by analyzing a large number of fecal samples from different individuals. In this study, we compared nine of these existing catalogues and found that there was surprisingly little overlap between them, with 82% of the viral sequences being unique to a single catalogue. To further expand the available data, we analyzed nearly 8,000 additional fecal samples from infants. By combining all this ressources, we created a unified resource called the Aggregated Gut Viral Catalogue (AVrC), which contains more than a million distinct viral sequences, representing nearly 450,000 different viral species. This catalogue, which is easily accessible to the scientific community through a user-friendly web interface, provides a valuable tool for exploring the vast diversity of the human gut virome and its potential implications for human health.

microbiology↗

bioRxiv2021

Cyanolichen microbiome contains novel viruses that encode genes to promote microbial metabolism

Lichen thalli are formed through the symbiotic association of a filamentous fungus and photosynthetic green alga and/or cyanobacterium. Recent studies have revealed lichens also host highly diverse communities of secondary fungal and bacterial symbionts, yet few studies have examined the viral component within these complex symbioses. Here, we describe viral biodiversity and functions in cyanolichens collected from across North America and Europe. As current machine learning viral-detection tools are not trained on complex eukaryotic metagenomes, we first developed efficient methods to remove eukaryotic reads prior to viral detection and a custom pipeline to validate viral contigs predicted with three machine-learning methods. Our resulting high-quality viral data illustrate that every cyanolichen thallus contains diverse viruses that are distinct from viruses in other terrestrial ecosystems. In addition to cyanobacteria, predicted viral hosts include other lichen-associated bacterial lineages and algae, although a large fraction of viral contigs had no host prediction. Functional annotation of cyanolichen viral sequences reveals numerous viral-encoded auxiliary metabolic genes (AMGs) involved in amino acid, nucleotide, and carbohydrate metabolism, including AMGs for secondary metabolism (antibiotics and antimicrobials) and fatty acid biosynthesis. Overall, the diversity of cyanolichen AMGs suggests that viruses may alter microbial interactions within these complex symbiotic assemblages.

microbiology↗