Inoue A, Goda I, Kojima I, Esaki M, Okuya K, Ozawa M . Establishment of a circular polymerase extension reaction-based reverse genetics system for porcine reproductive and respiratory syndrome2026 · 担当区分： 最終著者, 責任著者 記述言語： 英語 掲載種別： 研究論文（学術雑誌） 出版者・発行元： Veterinary Microbiology Porcine reproductive and respiratory syndrome virus (PRRSV) continues to cause substantial economic losses in the global swine industry. Reverse genetics is an essential approach for elucidating viral replication mechanisms, pathogenicity, and vaccine design; however, existing reverse genetics systems for PRRSV are often technically demanding and time-consuming due to the large and genetically unstable viral genome. Here, we established a reverse genetics system for PRRSV based on the circular polymerase extension reaction (CPER), a bacteria-free method for assembling full-length viral genomes. Infectious PRRSV was successfully rescued following transfection of CPER-assembled DNA into human embryonic kidney-derived HEK293T cells. The rescued virus exhibited growth kinetics and plaque morphology comparable to those of the parental strain in porcine alveolar macrophage-derived PAM-T43 cells. To demonstrate the applicability of this system for genetic manipulation, targeted synonymous mutations were introduced into the ORF5 gene, and the resulting mutant virus was successfully recovered and genetically confirmed. These results indicate that the CPER-based reverse genetics system provides a rapid and flexible platform for generating genetically defined PRRSV variants. This approach is expected to facilitate studies on PRRSV pathogenesis, antigenic variation, and vaccine development, thereby contributing to improved control strategies for this economically important swine disease. DOI： 10.1016/j.vetmic.2026.111053 Scopus PubMed
Esaki M, Okuya K, Onuma M, Ozawa M . Genetically distinct H5N2 high pathogenicity avian influenza virus isolated from a peregrine falcon on Amami-Oshima Island, Japan, harboring enhanced patho2025 · 担当区分： 最終著者, 責任著者 記述言語： 英語 掲載種別： 研究論文（学術雑誌） 出版者・発行元： Virology We report the first confirmed case of high pathogenicity avian influenza virus (HPAIV) infection in a peregrine falcon (Falco peregrinus) on Amami-Oshima Island, a region known for its unique biodiversity. The isolate, A/peregrine falcon/Kagoshima/5704A001/2025 (H5N2), showed genetic and phylogenetic divergence across all eight gene segments. Specific amino acids in the PA protein associated with increased pathogenicity in birds and mammals were also identified. Despite global surveillance, related ancestral viruses remain unreported. These findings highlight the need for expanded geographic surveillance and timely, transparent data sharing to better track and respond to emerging HPAIV threats. DOI： 10.1016/j.virol.2026.110794 Scopus PubMed
