Clade 2.3.4.4b H5N1 high pathogenicity avian influenza virus (HPAIV) from the 2021/22 epizootic is highly duck adapted and poorly adapted to chickens

James, J.; Billington, E.; Warren, C. J.; De Sliva, D.; Di Genova, C.; Airey, M.; Meyer, S. M.; Lewis, T.; Peers-Dent, J.; Thomas, S. S.; Lofts, A.; Furman, N.; Slomka, M. J.; Brown, I. H.; Banyard, A. C.

doi:10.1101/2023.02.07.527270

bioRxiv · 10.1101/2023.02.07.527270

Clade 2.3.4.4b H5N1 high pathogenicity avian influenza virus (HPAIV) from the 2021/22 epizootic is highly duck adapted and poorly adapted to chickens

James, J.·Billington, E.·Warren, C. J.·De Sliva, D.·Di Genova, C.·Airey, M.·Meyer, S. M.·Lewis, T.·Peers-Dent, J.·Thomas, S. S.·Lofts, A.·Furman, N.·Slomka, M. J.·Brown, I. H.·Banyard, A. C.

View original source ↗Export metadata ↓

Abstract

The 2021/2022 epizootic of high pathogenicity avian influenza (HPAIV) remains one of the largest ever in the UK, being caused by a clade 2.3.4.4b H5N1 HPAIV. This epizootic affected more than 145 poultry premises, most likely through independent incursion from infected wild birds, supported by more than 1700 individual detections of H5N1 from wild bird mortalities. Here an H5N1 HPAIV, representative of this epizootic (H5N1-21), was used to investigate its virulence, pathogenesis and transmission in layer chickens and pekin ducks, two species of epidemiological importance. We inoculated both avian species with decreasing H5N1-21 doses. The virus was highly infectious in ducks, with high infection levels and accompanying shedding of viral RNA, even in ducks inoculated with the lowest dose, reflecting the strong waterfowl adaptation of the clade 2.3.4.4 HPAIVs. Duck-to-duck transmission was very efficient, coupled with high environmental contamination. H5N1-21 was frequently detected in water sources, serving as likely sources of infection for ducks, but inhalable dust and aerosols represented low transmission risks. In contrast, chickens inoculated with the highest dose exhibited lower rates of infection compared to ducks. There was no evidence for experimental H5N1-21 transmission to any naive chickens, in two stocking density scenarios, coupled with minimal and infrequent contamination being detected in the chicken environment. Systemic viral dissemination to multiple organs reflected the pathogenesis and high mortalities in both species. In summary, the H5N1-21 virus is highly infectious and transmissible in anseriformes, yet comparatively poorly adapted to galliformes, supporting strong host preferences for wild waterfowl. Key environmental matrices were also identified as being important in the epidemiological spread of this virus during the continuing epizootic.

Source connections

Published article ↗

Explore related subjects

microbiology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

James, J., Billington, E., Warren, C. J., De Sliva, D., Di Genova, C., Airey, M., Meyer, S. M., Lewis, T., Peers-Dent, J., Thomas, S. S., Lofts, A., Furman, N., Slomka, M. J., Brown, I. H., Banyard, A. C.. 2023-02-07. Clade 2.3.4.4b H5N1 high pathogenicity avian influenza virus (HPAIV) from the 2021/22 epizootic is highly duck adapted and poorly adapted to chickens. https://doi.org/10.1101/2023.02.07.527270

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Polyphyletic origins and lineage-specific expansion of chemosensory systems in phylum Actinomycetota

Phylum Actinomycetota (syn. Actinobacteriota or Actinobacteria), one of the largest well-studied bacterial phyla, is renowned for complex morphology, non-motility, ecological versatility, and secondary metabolite production. Chemosensory systems (CSS) are among the most sophisticated prokaryotic signal transduction architectures, yet their evolutionary distribution in this phylum remains poorly understood. Here, a comparative genomic analysis of 693 high-quality genomes spanning the phylum resolves the diversity, distribution, and evolutionary trajectories of CSS. Despite extensive genomic complexity and ecological versatility, only 6.9% of genomes encode complete CSS clusters, confined to a subset of lineages within a few classes, indicating lineage-specific retention or loss. In contrast, two-component systems (TCS) are ubiquitously abundant, with hybrid kinases enriched in CSS-deficient classes, suggesting functional compensation for the absence of dedicated chemosensory pathways. Basal lineages retain simplified CSS (F1 or F5), whereas Actinomycetes show lineage-specific expansion into multiple classes (F5, F8, F9, and ACF), often co-occurring, indicative of enhanced sensory complexity. The phylogeny of CheA homologs shows a polyphyletic distribution, supporting a mosaic evolutionary history shaped by multiple independent acquisitions, diversification, and gene loss. Collectively, our findings show that, unlike motile bacteria, members of Actinomycetota rely predominantly on TCS-driven regulatory networks, with CSS retained only in select lineages where ecological demands require enhanced environmental sensing. This work provides a phylum-wide evolutionary framework for the emergence, diversification, and functional specialization of CSS in non-motile bacteria.

microbiology↗

bioRxiv2026

Integrating Microbial Ecology and Sustainability: Linking Agricultural Waste Gas Streams to Microbial Community Shifts in a Photobioreactor

Photobioreactors (PBRs) coupled to animal housing offer potential for mitigating gaseous emissions such as CO2 and NH3 while simultaneously producing biomass. Here, we present a time-resolved characterization of microbial community dynamics, with a focus on the genetic potential for carbon and nitrogen metabolism. Using a cone-shaped, helical PBR cultivating Arthrospira platensis (Spirulina) and supplied with exhaust air from a chicken house, we characterized microbial communities over continuous exhaust-air exposure and periodic biomass harvesting. Microbiome and gene-centric profiling revealed temporal variation in community composition and in the representation of genes associated with carbon and nitrogen metabolism. Cycle-based dissolved inorganic nitrogen balances showed that the decrease in dissolved inorganic nitrogen was only partially recovered in harvested biomass, while ammonia-oxidizing microorganisms were associated with structured, low-light niches. These observations indicate ammonia-oxidizing potential but do not establish a quantitatively relevant nitrification flux. Structured carrier matrices provided attached-growth niches harboring microbial populations underrepresented in the circulating suspension, while pre-colonized carriers facilitated biomass development during re-inoculation. Overall, our results show that coupling PBRs to agricultural exhaust streams can support biomass production while sustaining spatially structured microbial communities with taxonomic and functional potential. These findings may inform their further development for emission mitigation and circular biomass production.

microbiology↗

bioRxiv2026

Engineered DNA materials shape microbial physiology and ecological selection

Extracellular DNA (eDNA) is both a structural component of microbial biofilms and a potential reservoir of genetic information, yet its role as an ecological material remains largely unexplored. Here we establish engineered extracellular materials as determinants of microbial physiology and community assembly across increasing biological complexity. A three-dimensional DNA hydrogel altered bacterial stress-associated responses, elicited species-dependent phenotypes and transcriptional changes in a defined consortium, and shaped community succession in wastewater-derived microbiomes. Distinct responses to surface-bound oligonucleotides reveal that DNA presentation matters beyond its mere presence. Strikingly, metagenomic sequencing identified rare, hydrogel-specific candidate junctions linking material-derived DNA to microbial genomic sequences, suggesting a previously unexplored interface between extracellular DNA materials and microbial genetic information. These findings reveal a dual role for engineered DNA: its material organization shapes microbial physiology and ecological selection, while its encoded sequences may engage with microbial genomic processes.

microbiology↗