Biology subjects

Saghafian, M.

Publications and source records attributed to Saghafian, M..

3 recordsLinked to original sources

bioRxiv2026

Highly Pathogenic Avian Influenza Viruses H5N1 and H5N5 in Red Foxes (Vulpes vulpes) in Norway during 2022-2024

Since 2020, highly pathogenic avian influenza (HPAI) A(H5Nx) clade 2.3.4.4b viruses have spread globally, causing extensive outbreaks in domestic and wild birds. Increased circulation has resulted in frequent spillover to mammals, and occasional mammal-to-mammal transmission. Although human infections remain rare, the zoonotic potential of these viruses continues to be a public health concern. We investigated six cases of HPAI in red foxes (Vulpes vulpes) in Norway during 2022-2024 and identified infections with H5N1 and H5N5 viruses. Pathological and virological investigations demonstrated systemic infection, with prominent lesions in the brain and/or lungs. Phylogenetic analyses showed high similarity between viruses detected in foxes and those concurrently circulating in wild birds. The mammalian adaptation marker PB2:E627K was identified in one H5N1 virus and as a minority variant in a second H5N1 virus.

microbiology↗

bioRxiv2025

Highly Pathogenic Avian Influenza A(H5N1) Caused Mass Death among Black-legged Kittiwakes (Rissa tridactyla) in Norway, 2023

In 2023, highly pathogenic avian influenza (HPAI) heavily affected gulls in Europe. In July, a mass mortality event was reported in the Black-legged Kittiwake (Rissa tridactyla) breeding colony at Ekkeroy in Northern Norway. The cause was confirmed to be infection with the HPAI H5N1 clade 2.3.4.4b virus, genotype EA-2022-BB. We describe the outbreak in Kittiwakes, including pathological and virological investigations, and discuss the management and zoonotic potential. With more than 15,000 dead birds reported, we estimate that the outbreak caused a reduction in the Kittiwake population at Ekkeroy of at least 50%. Diseased birds exhibited neurological signs. Necropsy of ten birds revealed a peracute fatal systemic disease, with severe lesions in the brain and pancreas co-localizing with the presence of viral RNA and antigen. Vascular expression of 2,3-linked sialic acids and viral RNA/antigen may reflect hematogenous virus spread. Further studies should investigate the long-term impact of HPAI on Kittiwake populations.

microbiology↗

bioRxiv2025

Virus-inclusive single-nucleus RNA sequencing reveals two distinct endothelial response patterns in infectious salmon anaemia.

Viral replication in endothelial cells is a hallmark of many viral diseases in humans and other animals, underscoring the importance of understanding cellular mechanisms that restrict viral replication and the associated consequences for vascular health. Pathogenic variants of infectious salmon anaemia virus (ISAV, Isavirus salaris) target endothelial cells of Atlantic salmon (Salmo salar L.), causing severe systemic disease and major losses during outbreaks in aquaculture. To better understand the endothelial response to ISAV, we used single nucleus RNA-sequencing at pre-clinical (12 days post infection, dpi) and clinical (16 dpi) stages of infection. Our approach enables an assessment of transcriptomic responses for different endothelial subpopulations at unprecedented resolution. ISAV RNA was predominantly detected in endothelial cells, which, along with mononuclear phagocytes, showed the highest number of differentially regulated genes at both time points. At 12 dpi, differentially expressed genes in endothelial cells were enriched for pathways related to NOD-like receptor signaling, antiviral responses, and regulation of programmed cell death. By 16 dpi, we observed a shift toward enrichment of pathways associated with cellular senescence, apelin signaling, and insulin signaling. We identified two distinct infection-related states at both time points: a virus-permissive state characterized by upregulation of genes involved in protein synthesis, small GTPase signaling, and MAPK activity, and a bystander phenotype marked by activation of antiviral responses, immune signaling, and translational regulation. This study is the first to capture the individual cell type responses to ISAV infection, and to characterize the in vivo endothelial response to active viral replication at single-cell resolution in any species.

immunology↗